Elliptic Curve Crypto - Recent changes [en]

SEPIC.tex

Rational Point — Fri, 24 Apr 2026 14:13:47 GMT

Source code for File:SEPIC.pdf

← Older revision		Revision as of 14:13, 24 April 2026
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	$$		$$

	Increasing the duty cycle $\tau/T$ will increase the potential $V_{P_\textrm{off}}$ which is available at the output less the forward drop through the diode $D_1$, but it will correspondingly decrease the clock-cycle-averaged current available at the increased potential. A Pulse Width Modulator with a feedback loop will assist in maintaining a stable output potential from a variable input potential from solar panels.		Increasing the duty cycle $D=\tau/T$ will increase the potential $V_{P_\textrm{off}}$ which is available at the output less the forward drop through the diode $D_1$, but it will correspondingly decrease the clock-cycle-averaged current available at the increased potential. A Pulse Width Modulator with a feedback loop will assist in maintaining a stable output potential from a variable input potential from solar panels.

	\section{Energy transfer per clock cycle}		\section{Energy transfer per clock cycle}
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	Zhang \cite{zhang} suggests choosing inductors of a value that will allow a 40\% ripple in current at the switching frequency. In effect, that causes perhaps 64\% of the total energy stored in an inductor to be transferred each clock cycle, which appears to be a good practical limit of tolerable ``ripple'' under conditions of light load or open circuit among other considerations.		Zhang \cite{zhang} suggests choosing inductors of a value that will allow a 40\% ripple in current at the switching frequency. In effect, that causes perhaps 64\% of the total energy stored in an inductor to be transferred each clock cycle, which appears to be a good practical limit of tolerable ``ripple'' under conditions of light load or open circuit among other considerations.

	We suggest using heavy gauge wire on a heavy iron core to carry large currents to avoid overheating and/or saturating the core. This only permits relatively few turns of wire and will not result in any excessively large inductance.		We suggest using heavy gauge wire on a heavy iron core to carry large currents to avoid overheating and/or saturating the core. This only permits relatively few turns of wire and will not result in any excessively large inductance. However this approach limits the system to low frequencies.

	The capacitors in a coupled SEPIC system are movable~~, and~~ their exact values do not seem to be critical.		The capacitors in a coupled SEPIC system are movable: their exact values and placements do not seem to be critical, and may need to be determined experimentally.

	\section{Size and scale of systems proposed}		\section{Size and scale of systems proposed}
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	The selection of components is based on how much ``ripple voltage'' and possible overheating of components we are willing to tolerate versus how much money we can afford and are willing to spend on bigger and better components for reliability and smoothness of the power supply system.		The selection of components is based on how much ``ripple voltage'' and possible overheating of components we are willing to tolerate versus how much money we can afford and are willing to spend on bigger and better components for reliability and smoothness of the power supply system.

			It is particularly important to pay attention to officially published datasheets on electronic component parts and ICs. Those are the legal contracts of technical specifications on which the chips are sold, and they contain all the information you need to know from the manufacturer on the particular product you are using. Other comments or opinions from engineers or salesmen, personal or otherwise, are ultimately irrelevant, as they have presumably already stated all of the information to which they can be held accountable on the datasheet.

			Once you ``make'' or ``build,'' you are no longer a consumer but a potential competitor and arch-rival making a possibly hostile use of the firm's component parts which you are effectively taking over and re-purposing as parts of your own final product. So if you are in direct competition with that firm, you would be well advised to avoid any ``vendor lock-in'' and be prepared to find alternatives or substitutes for their component parts.

			\begin{quote}
			``We sell electronic component parts and chips, and we have engineers who would love to talk to you about the technical details, but (obviously) our goals and objectives are merely to protect and defend our intellectual property and if at all possible to prevent you from making or building anything in direct competition with any of our own products.''
			\end{quote}

			\noindent To view the published datasheet with such a jaundiced eye and jaded opinions, the Amish farmer's honesty won't permit it at all.

	\subsection{Power MOSFETs or IGBTs}		\subsection{Power MOSFETs or IGBTs}
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	The ``Arduino'' also has a rudimentary pulse width modulation ``analog output'' running at about 0.5~kHz \cite{arduino-pwm}, which is adequate for our purposes as long as we design and plan for the very low frequency.		The ``Arduino'' also has a rudimentary pulse width modulation ``analog output'' running at about 0.5~kHz \cite{arduino-pwm}, which is adequate for our purposes as long as we design and plan for the very low frequency.
	~~\subsection{Logic level power supply}~~

	\begin{figure}		\begin{figure}
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	\draw (2,6) node[circ]{} to[resistor, label=$R_2$] ++(0,-3) node[circ, name=qb0]{}		\draw (2,6) node[circ]{} to[resistor, label=$R_2$] ++(0,-3) node[circ, name=qb0]{}
	to[zzDo, invert, label=$D_2$] ++(0,-3) node[circ]{};		to[zzDo, invert, label=$D_2$] ++(0,-3) node[circ]{};
	\draw (4,3) node[~~pnp~~, name=q1]{$Q_2$};		\draw (4,3) node[npn, name=q1]{$Q_2$};
	\draw (qb0) -- (q1.base);		\draw (qb0) -- (q1.base);
	\draw (2,6) -- ++(2,0) -- (q1.~~emitter~~);		\draw (2,6) -- ++(2,0) -- (q1.collector);
	\draw (2,0) -- ++(3,0) node[circ, name=j3]{} -- ++(2,0) node[circ, name=j4]{} -- ++(1,0) node[ocirc, label=$GND$]{};		\draw (2,0) -- ++(3,0) node[circ, name=j3]{} -- ++(2,0) node[circ, name=j4]{} -- ++(1,0) node[ocirc, label=$GND$]{};
	\draw (q1.~~collector~~) -- ++(1,0) node[circ, name=j1]{} to[cute inductor, inductors/coils=3, label=$L_4$]		\draw (q1.emitter) -- ++(1,0) node[circ, name=j1]{} to[cute inductor, inductors/coils=3, label=$L_4$]
	++(2,0) node[circ, name=j2]{} -- ++(1,0) node[ocirc, label=$V_{CC}$]{};		++(2,0) node[circ, name=j2]{} -- ++(1,0) node[ocirc, label=$V_{CC}$]{};
	\node[~~below~~ right, font=\scriptsize] at (q1.emitter){$E$};		\node[above right, font=\scriptsize] at (q1.emitter){$E$};
	\node[~~below~~, font=\scriptsize] at (q1.base){$B$};		\node[above, font=\scriptsize] at (q1.base){$B$};
	\node[~~above~~ right, font=\scriptsize] at (q1.collector){$C$};		\node[below right, font=\scriptsize] at (q1.collector){$C$};
	\draw (j1) to[curved capacitor, label=$C_5$] (j3);		\draw (j1) to[curved capacitor, label=$C_5$] (j3);
	\draw (j2) to[curved capacitor, label=$C_6$] (j4);		\draw (j2) to[curved capacitor, label=$C_6$] (j4);
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	\end{figure}		\end{figure}

			\subsection{Logic level power supply}
	A simple Zener diode voltage regulator with a transistor current buffer \cite{zd-tr} as depicted in Figure~\ref{f2} should be used to power logic level circuits directly from highly variable power supplies if possible. This simple circuit also has the effect of an undervoltage lockout or UVLO \cite{uvlo-se}. Some hysteresis \cite{uvlo-h} would be desirable in order to avoid an amplified chattering effect from transistor $Q_2$ when the voltage supply is barely adequate and teetering at the edge of the lockout level.		A simple Zener diode voltage regulator with a transistor current buffer \cite{zd-tr} as depicted in Figure~\ref{f2} should be used to power logic level circuits directly from highly variable power supplies if possible. This simple circuit also has the effect of an undervoltage lockout or UVLO \cite{uvlo-se}. Some hysteresis \cite{uvlo-h} would be desirable in order to avoid an amplified chattering effect from transistor $Q_2$ when the voltage supply is barely adequate and teetering at the edge of the lockout level.

File:SEPIC.pdf

Rational Point — Fri, 24 Apr 2026 14:13:19 GMT

Rational Point uploaded a new version of File:SEPIC.pdf

New page

See [[SEPIC.tex]] for the source code for this document.

SEPIC.tex

Rational Point — Fri, 24 Apr 2026 03:44:14 GMT

Show changes

File:SEPIC.pdf

Rational Point — Fri, 24 Apr 2026 03:42:45 GMT

Rational Point uploaded a new version of File:SEPIC.pdf

New page

See [[SEPIC.tex]] for the source code for this document.

Magnetic permeability

Rational Point — Tue, 21 Apr 2026 15:48:48 GMT

Calculating the magnetic permeability of a toroid core

← Older revision		Revision as of 15:48, 21 April 2026
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	Problem: calculate the magnetic permeability of the material of which this core is made.		Problem: calculate the magnetic permeability of the material of which this core is made.

			=== The Biot–Savart Law for air-core inductors and coils in free space ===

			...

Solar systems

Rational Point — Mon, 20 Apr 2026 04:45:04 GMT

Charge controller: Zener Diode Regulator with Transistor Current Buffer

← Older revision		Revision as of 04:45, 20 April 2026
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	Capacitance, inductance and transistor performance characteristics, etc. of all component parts should be carefully measured and verified with appropriate field or bench test equipment.		Capacitance, inductance and transistor performance characteristics, etc. of all component parts should be carefully measured and verified with appropriate field or bench test equipment.

			A Zener diode with a resistor and a transistor <ref> ''Zener Diode Regulator with Transistor Current Buffer.'' 2015-08-26. https://www.digikey.com/en/maker/tutorials/2016/zener-diode-regulator-with-transistor-current-buffers</ref> may be helpful as a logic-level voltage supply for the charge controller itself to enable "wide ''V<sub>in</sub>''" functionality for integrated circuit power directly from the solar panels under varying sunlight conditions.

	=== Component selection and Bill of Materials ===		=== Component selection and Bill of Materials ===

FM radio

Rational Point — Mon, 20 Apr 2026 03:27:05 GMT

start article

New page

Various circuits exist for building simple FM radio receivers <ref>''Simple FM Radio.'' https://electronics-diy.com/simple-fm-radio.php</ref><ref>D. Prabakaran. ''Designing Simple FM Radio Receiver Circuit.'' August 16, 2023. https://www.electronicsforu.com/electronics-projects/simple-fm-receiver </ref><ref>''LEAP #476: Simplest Direct FM Receiver.'' https://leap.tardate.com/radio/fm/simplestdirectreceiver/</ref><ref>''How to Build a Simple FM Radio Receiver on a Breadboard.'' https://en.eeworld.com.cn/circuit/view/105092</ref>.

This one <ref>Boris Landoni. ''DiY FM Micro Receiver.'' https://www.open-electronics.org/diy-fm-micro-receiver/</ref> has stereo output and uses an integrated circuit.

File:Crystal-radio.png

Rational Point — Sun, 19 Apr 2026 18:00:12 GMT

Rational Point uploaded a new version of File:Crystal-radio.png fixed capacitor value

New page

Basic Crystal radio circuit
https://www.allaboutcircuits.com/textbook/semiconductors/chpt-9/radio-circuits/

Crystal radio

Rational Point — Sun, 19 Apr 2026 17:56:42 GMT

minor edits

← Older revision		Revision as of 17:56, 19 April 2026
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	Building a simple crystal radio is, or ought to be, a basic survival skill.		Building a simple AM crystal radio is, or ought to be, a basic survival skill.

	This circuit <ref>All About Circuits. ''Textbook // Semiconductors // Practical Analog Semiconductor Circuits // Radio Circuits.'' https://www.allaboutcircuits.com/textbook/semiconductors/chpt-9/radio-circuits/</ref>		This circuit <ref>All About Circuits. ''Textbook // Semiconductors // Practical Analog Semiconductor Circuits // Radio Circuits.'' https://www.allaboutcircuits.com/textbook/semiconductors/chpt-9/radio-circuits/</ref>
	shows an antenna tuned with an inductor of 240μH and a variable capacitor of ~~365pF~~.		shows an antenna tuned with an inductor of 240μH and a variable capacitor of 365 pF.

	[[File:Crystal-radio.png\|frame\|center\|Simple crystal radio circuit]]		[[File:Crystal-radio.png\|frame\|center\|Simple crystal radio circuit]]

	The resonant frequency for this tuning ~~will be~~ about		The resonant frequency for this tuning with the variable capacitor set at 365 pF starts at about

	:''f'' = 1 / 2π√(LC) =~ 537.73472 kilohertz		:''f'' = 1 / 2π√(LC) =~ 537.73472 kilohertz

	If the variable capacitance is reduced to 36.~~5pF~~, then the resonant frequency will be increased to 1700.46649 kilohertz, the other end of the popular AM broadcast radio band, which is about exactly half a decade wide, spanning a ratio of √10 on the radio spectrum.		If the variable capacitance is ''reduced'' to 36.5 pF, then the resonant frequency will be increased to 1700.46649 kilohertz, the other end of the popular AM broadcast radio band, which is about exactly half a decade wide, spanning a ratio of √10 on the radio spectrum.

Crystal radio

Rational Point — Sun, 19 Apr 2026 17:53:12 GMT

Simple crystal radio circuit

New page

Building a simple crystal radio is, or ought to be, a basic survival skill.

This circuit <ref>All About Circuits. ''Textbook // Semiconductors // Practical Analog Semiconductor Circuits // Radio Circuits.'' https://www.allaboutcircuits.com/textbook/semiconductors/chpt-9/radio-circuits/</ref>
shows an antenna tuned with an inductor of 240μH and a variable capacitor of 365pF.

[[File:Crystal-radio.png|frame|center|Simple crystal radio circuit]]

The resonant frequency for this tuning will be about

:''f'' = 1 / 2π√(LC) =~ 537.73472 kilohertz

If the variable capacitance is reduced to 36.5pF, then the resonant frequency will be increased to 1700.46649 kilohertz, the other end of the popular AM broadcast radio band, which is about exactly half a decade wide, spanning a ratio of √10 on the radio spectrum.

File:Crystal-radio.png

Rational Point — Sun, 19 Apr 2026 17:51:37 GMT

Rational Point uploaded File:Crystal-radio.png

New page

Basic Crystal radio circuit
https://www.allaboutcircuits.com/textbook/semiconductors/chpt-9/radio-circuits/

File:SEPIC.pdf

Rational Point — Fri, 17 Apr 2026 05:55:16 GMT

Rational Point uploaded a new version of File:SEPIC.pdf

New page

See [[SEPIC.tex]] for the source code for this document.

SEPIC.tex

Rational Point — Fri, 17 Apr 2026 05:54:51 GMT

Arduino

← Older revision		Revision as of 05:54, 17 April 2026
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	url = {https://www.monolithicpower.com/en/learning/mpscholar/power-electronics/dc-dc-converters/sepic-converters}		url = {https://www.monolithicpower.com/en/learning/mpscholar/power-electronics/dc-dc-converters/sepic-converters}
	}		}
			@article{arduino-pwm,
			author = {Timothy Hirzel},
			title = {Basics of PWM (Pulse Width Modulation)},
			journal = {Arduino Docs},
			year = {2022},
			url = {https://docs.arduino.cc/learn/microcontrollers/analog-output/}
			}

	\end{filecontents}		\end{filecontents}
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	\subsubsection{Low frequency}		\subsubsection{Low frequency}

	The LM555 \cite{LM555} or similar ICs from many manufacturers may be used for frequencies below 20~kHz, but the 555 is a general purpose timer which will require additional customization and circuitry to use specifically for pulse width modulation. There is no reason we cannot go as low as 400, 60 or even 50~Hz. Larger inductors and capacitors will be required in these cases, but the converter will be more efficient may produce smoother, cleaner power.		The LM555 \cite{LM555} or similar ICs from many manufacturers may be used for frequencies below 20~kHz, but the 555 is a general purpose timer which will require additional customization and circuitry to use specifically for pulse width modulation. There is no reason we cannot go as low as 400, 60 or even 50~Hz. Larger inductors and capacitors will be required in these cases, but the converter will be more efficient and may produce smoother, cleaner power.

			The ``Arduino'' also has a rudimentary pulse width modulation ``analog output'' running at about 0.5~kHz \cite{arduino-pwm}, which is adequate for our purposes as long as we design and plan for the very low frequency.

	\subsection{The feedback loop}		\subsection{The feedback loop}

File:SEPIC.pdf

Rational Point — Fri, 17 Apr 2026 05:16:21 GMT

Rational Point uploaded a new version of File:SEPIC.pdf

New page

See [[SEPIC.tex]] for the source code for this document.

SEPIC.tex

Rational Point — Fri, 17 Apr 2026 05:15:27 GMT

something is missing

Show changes

File:SEPIC.pdf

Rational Point — Tue, 14 Apr 2026 04:08:09 GMT

Rational Point uploaded a new version of File:SEPIC.pdf new section; more refs

← Older revision	Revision as of 04:08, 14 April 2026
(One intermediate revision by the same user not shown)
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		See [[SEPIC.tex]] for the source code for this document.

SEPIC.tex

Rational Point — Mon, 13 Apr 2026 23:51:20 GMT

source code

New page

<syntaxhighlight lang="latex" line="">
\documentclass{article}
\usepackage{currfile}
\usepackage[utf8]{inputenc}
\usepackage{textcomp}
\usepackage{tikz}
\usepackage[american]{circuitikz}
\usepackage[backend=biber, style=numeric]{biblatex}
\usepackage{hyperref}
\hypersetup{
colorlinks=true,
linkcolor=blue,
filecolor=magenta,
urlcolor=cyan,
pdftitle={Controlling and Driving the SEPIC}
}
\begin{filecontents}[overwrite,nosearch]{\currfilebase.bib}
@misc{IXFN520N075T2,
author = {{Littelfuse/IXYS}},
title = {IXFN520N075T2: DiscMSFT NChTrenchGateGen2 SOT-227B(mini | Series: Gen2},
url = {https://www.littelfuse.com/products/power-semiconductors-control-ics/mosfets-si-sic/n-channel-trench-gate/gen2/ixfn520n075t2}
}
@misc{VS-FC420SA10,
author = {{Vishay Semiconductors}},
title = {VS-FC420SA10 PRODUCT INFORMATION:
SOT-227 Power Module Single Switch - Power MOSFET, 420 A},
url = {https://www.vishay.com/en/product/95793/}
}
@misc{STPS200170TV1,
author={{ST Microelectronics}},
title={STPS200170TV1: 170 V, 200 A dual Power Schottky Rectifier},
url={https://www.st.com/en/diodes-and-rectifiers/stps200170tv1.html}
}
@misc{VS-203CNQ100PbF,
author = {{Vishay Semiconductors}},
title = {VS-203CNQ100PbF PRODUCT INFORMATION:
High Performance Schottky Rectifier, 200 A},
url = {https://www.vishay.com/en/product/94155/}
}
@misc{apmcap,
author = {{Absolute Pro Music}},
title = {Search for ``capacitor'' ...},
url = {https://absolutepromusic.com/search?q=capacitor}
}
@misc{bossaudiocap,
author = {{Boss Audio}},
title = {Search for ``capacitor'' ...},
url = {https://bossaudio.com/collections/sale?q=capacitor}
}
@misc{LM5155,
author = {{Texas Instruments}},
title = {LM5155: 2.2-MHz wide VIN, 1.5-A MOSFET driver, non-synchronous boost controller},
url = {https://www.ti.com/product/LM5155}
}
@misc{LM51551,
author={{Texas Instruments}},
title = {LM51551: 2.2-MHz wide VIN nonsynchronous boost, flyback, {\&} SEPIC controller with hiccup},
url = {https://www.ti.com/product/LM51551}
}
@misc{LM5156H,
author = {{Texas Instruments}},
title = {LM5156H: 2.2-MHz wide VIN nonsynchronous boost, flyback, {\&} SEPIC controller with dual random spread spectrum},
url = {https://www.ti.com/product/LM5156H}
}
@misc{LM51561,
author = {{Texas Instruments}},
title = {LM51561: 2.2MHz Wide Input Nonsynchronous Boost, SEPIC, Flyback Controller with Spread Spectrum},
url = {https://www.ti.com/product/LM51561}
}
@misc{LM51561H,
author = {{Texas Instruments}},
title = {LM51561H: 2.2-MHz wide VIN nonsynchronous boost, flyback, {\&} SEPIC controller with spread spectrum and hiccup},
url = {https://www.ti.com/product/LM51561H}
}
@misc{TL5001,
author = {{Texas Instruments}},
title = {TL5001: PWM Controller with wide input range, with \textpm 5{\%} tolerance on reference, operation --20\textdegree C to 85\textdegree C},
url = {https://www.ti.com/product/TL5001}
}
@misc{TL5001A,
author = {{Texas Instruments}},
title = {TL5001A: PWM Controller with wide input range, with \textpm 3{\%} tolerance on reference, operation --20\textdegree C to 85\textdegree C},
url = {https://www.ti.com/product/TL5001A}
}
@misc{TL5001M,
author = {{Texas Instruments}},
title = {TL5001M: PWM Controller with wide input range, with \textpm 5{\%} tolerance on reference, operation --55\textdegree C to 125\textdegree C},
url = {https://www.ti.com/product/TL5001M}
}
@misc{TL5001AM,
author = {{Texas Instruments}},
title = {TL5001AM: PWM Controller with wide input range, with \textpm 3{\%} tolerance on reference, operation --55\textdegree C to 125\textdegree C},
url = {https://www.ti.com/product/TL5001AM}
}
@misc{LM555,
author = {{Texas Instruments}},
title = {LM555: Highly Stable 555 Timer},
url = {https://www.ti.com/product/LM555}
}

\end{filecontents}
\addbibresource{\currfilebase.bib}
%opening
\title{Controlling and Driving the SEPIC}
\author{--- NON-PUBLISHED WORK-IN-PROGRESS ---}

\begin{document}

\maketitle

\begin{abstract}
Investigating the ``Single Ended Primary Inductor Converter'' for use with residential, rooftop, commercial or industrial solar panels. The purpose of this study is to gain a more thorough understanding of the theory of operation of switching power supplies and ``charge controllers'' for solar panel systems before putting it in practice.
\end{abstract}
\tableofcontents
\begin{figure}
\begin{center}
\begin{circuitikz}
\draw (2,3) -- ++(-2,0) to[pvsource, invert, l_=$V_1$] ++(0,-3) -- ++(2,0);
\draw (2,3) node[circ]{} to[cute inductor, inductors/coils=5, l_=$L_1$, name=l1] ++(2,0) node[circ]{}
to[curved capacitor, label=$C_2$] ++(2,0) node[circ]{}
to[sDo, label=$D_1$, name=d1] ++(2,0)
to[cute choke, inductors/coils=3, label=$L_3$] ++(2,0) -- ++(0,-0.5) node[circ]{}
to[european resistor, label=$R_1$] ++(0,-2.5) -- ++(-2,0);
\draw (2,3) to[curved capacitor, l_=$C_1$] ++(0,-3) node[circ]{}
-- ++(2,0) node[circ]{};
\draw (4,1.5) node[nigfete, solderdot](Q1){$Q_1$};
\node [right, font=\tiny] at (Q1.S) {S};
\node [right, font=\tiny] at (Q1.D) {D};
\node [above, font=\tiny] at (Q1.G) {G};
\draw (Q1.D) -- (4,3); \draw (Q1.S) -- (4,0);
\draw (4,0) -- ++(2,0) node[circ]{} to[cute inductor, inductors/coils=5, l_=$L_2$, name=l2] ++(0,3);
\path (l1.lr dot) node[circ]{} (l2.lr dot) node[circ]{};
\draw[thick, double] (l1.core west) -- (l1.core east);
\draw[thick, double] (l2.core west) -- (l2.core east);
\draw (10,2.5) -- ++(-1,0) to[curved capacitor, l_=$C_3$] ++(0,-2.5) node[circ]{}
-- ++(-3,0);
\draw (Q1.G) --++ (0,-1) to[square voltage source, l_=$PWM$] ++(0,-2) node[ground]{};
\draw (10,0) node[circ]{} -- ++(0,-1.75) node[ground]{};
\draw (9,2.5) node[circ]{} -- ++(-1.33,0) -- ++(0,-3.25) -- ++ (-3.67,0) node[vcc, rotate=90, label={\qquad\qquad feedback}]{};
\end{circuitikz}
\end{center}
\caption{SEPIC circuit diagram}
\label{f1}
\end{figure}

\section{Introduction}

The SEPIC is one of a number of regulated switching power supply topologies, among which are included various versions of Buck, Boost, Buck--Boost, Flyback, Zeta and \'Cuk\footnote{Named after the prolific Serbo-Croatian--American inventor Slobodan \'Cuk of the California Institute of Technology.} DC-to-DC converters, to name a few.

\section{Discussion of the SEPIC topology}

If the inductors $L_1$ and $L_2$ in Figure~\ref{f1} are coupled, or wound on the same iron core as indicated by the black dots in the diagram, then the capacitors $C_1$ and $C_2$ are essentially placed in parallel, and one or the other may be removed without affecting the circuit much, because the inductance in canceled out for any electric current flowing through $L_1$ and back the opposite way through $L_2$. Nevertheless, the capacitors $C_1$ and $C_2$ as placed serve to protect the power MOSFET $Q_1$ from transient ``spikes'' in the inductive windings.

When $Q_1$ is switched on by the $PWM$, the current through $L_1$ increases, and when $Q_1$ is switched off, the remaining magnetic flux in the iron core forces the current through the other winding $L_2$ past the diode $D_1$ to keep the capacitor $C_3$ charged and continue supplying power to the load resistance $R_1$. This is omitting $C_2$ from consideration, and depending on mutual inductance alone.

However the circuit will still function if the inductors $L_1$ and $L_2$ are \textit{not} coupled and $C_2$ is present. In this case, $C_2$ is discharged by current flowing through $L_2$ when $Q_1$ is switched on, and additional supply current is admitted through $L_1$. Now when $Q_1$ is switched off, $C_2$ is charged again by current continuing through $L_1$, and the current that was flowing through $L_2$ as $C_2$ was discharging is suddenly switched and forced through the diode $D_1$ instead.

When the inductors $L_1$ and $L_2$ are coupled, and $C_2$ is present, there is additional redundancy, stability, and reliability for the circuit.

\section{Calculating the duty cycle of the PWM}

A simple way to figure out the duty cycle of the pulse width modulator needed to produce the desired potential at the output is to consider that the mean potential at the drain of $Q_1$ over the switching cycle must be equal to the input potential $V_1$, and that potential is equal to zero, or the forward voltage drop of the transistor during the time when it is on, which we want as small as possible. That potential must then be high enough during the time when the transistor is off to average out to the correct value over the entire clock cycle $T$. Let $\tau$ be the pulse width, or the time when the power transistor $Q_1$ is turned on and conducting electricity between its source and drain:

$$
\overline{V_Q} = V_1; \qquad V_{Q_\textrm{on}}=0;
\qquad V_{Q_\textrm{off}} = \frac{TV_1}{T-\tau}.
$$

Now consider the operating potential $V_P$ at the anode of diode $D_1$. At all times, $V_P$ is less than the potential $V_Q$ at the transistor drain by a difference equal to the input potential $V_1$.

$$
V_P = V_Q - V_1.
$$

So

$$
\overline{V_P} = 0; \qquad V_{P_\textrm{on}}=-V_1;
\qquad V_{P_\textrm{off}} = \frac{\tau V_1}{T-\tau}.
$$

Increasing the duty cycle $\tau/T$ will increase the potential $V_{P_\textrm{off}}$ which is available at the output less the forward drop through the diode $D_1$, but it will correspondingly decrease the clock-cycle-averaged current available at the increased potential. A Pulse Width Modulator with a feedback loop will assist in maintaining a stable output potential from a variable input potential from solar panels.

\section{Size and scale of systems proposed}

We propose off-grid solar electric power systems for use by ``sovereign citizens'' or ``freemen on the land'' (or even banks or broker houses that desire back-up power and money savings at the city electric meter) with about a dozen solar panels rated at 18V and 200W each, all connected in parallel to serve a common automotive-like 12V electrical system for which many accessories are commonly available, as well as inverters to generate 110VAC if desired.

\section{Selection of components and bill of materials}

The selection of components is based on how much ``'ripple voltage'' and possible overheating of components we are willing to tolerate versus how much money we can afford and are willing to spend on bigger and better components for reliability and smoothness of the power supply system.

\subsection{Power MOSFETs or IGBTs}

For $Q_1$ in Figure~\ref{f1}, the Littelfuse/IXYS IXFN520N075T2 \cite{IXFN520N075T2} or the Vishay VS-FC420SA10 \cite{VS-FC420SA10} might be useful. IGBTs are better than MOSFETs for higher frequency switching but are much less desireable for a low-voltage system because of the forward voltage drop. Power MOSFETs may also require a higher gate voltage to turn on.

\subsection{Power Schottky rectifier diodes}

The ST Microelectronics STPS200170TV1 \cite{STPS200170TV1} and the Vishay VS-203CNQ100PbF \cite{VS-203CNQ100PbF} are likely candidates.

\subsection{Power audio capacitors}

We suggest using power audio capacitors from a music supply store \cite{apmcap,bossaudiocap} for the capacitors $C_1$, $C_2$ and $C_3$ in Figure~\ref{f1}, and certainly for that matter our proposed system will be capable of powering the high-end stereo systems offered at those stores. Check ratings carefully for use with 18--24 V. It may be possible to use two identical capacitors in series to double the voltage rating. Some care will be needed to switch them on to avoid a short-circuit inrush current.

\subsection{Heavy iron inductors and power chokes}

Inductors and chokes are to be wound by hand with varnished magnet wire of adquate gauge on suitably heavy toroidal cores of laminated mild electrical steel or ferrite to prevent saturation in normal use. The use of closed toroidal cores reduces radio and audio systems interference.

\subsection{Pulse Width Modulators}

We suggest a Texas Instruments line-up of pulse width modulators depending on the desired frequency.

\subsubsection{High frequency}

The LM515xx series \cite{LM5155,LM51551,LM5156H,LM51561,LM51561H} of pulse width modulators offer a dynamically programmable switching frequency ranging from 100 kHz to 2.2 MHz. Switching in the megahertz range for our application may incur excessive power losses and inefficiency in the large power MOSFETs \cite{STPS200170TV1,VS-203CNQ100PbF}.

\subsubsection{Medium frequency}

The TL5001xx series PWMs \cite{TL5001,TL5001A,TL5001M,TL5001AM} operate in the range of 20 kHz to 500 kHz.

\subsubsection{Low frequency}

The LM555 \cite{LM555} or similar ICs from many manufacturers may be used for frequencies below 20 kHz, but the 555 is a general purpose timer which will require additional customization and circuitry to use specifically for pulse width modulation.
\subsection{The feedback loop}

There needs to be a stable and reliable automated method of adjusting the duty cycle of the PWM up and down between certain limits based on the difference between the desired correct output voltage and the actual output voltage measured.

\printbibliography
\end{document}

</syntaxhighlight>

Solar systems

Rational Point — Mon, 13 Apr 2026 23:45:28 GMT

link

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	=== Component selection and Bill of Materials ===		=== Component selection and Bill of Materials ===

			''See [[File:SEPIC.pdf]] for details.''

	The heart of the controller is a Pulse Width Modulation chip <ref>Some manufacturers and corporations will not like our attitude for referring to their integrated circuits as "chips" for sure, but at pawn shops and online auction sites selling jewelry and electronics one should not be ashamed to call them that. We have no opinions on offers of free samples direct from manufacturers or wholesalers, other than that they apparently contact local cops to enforce a litany of unwritten rules and unspoken codes sometimes pertaining to "intellectual property" by which hobbyists as opposed to professionals are supposed to abide.</ref> like the Texas Instruments TL5001AMJG <ref>PWM Controller with wide input range, with ±3% tolerance on reference, operation –55°C to 125°C https://www.ti.com/product/TL5001AM</ref>. These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.		The heart of the controller is a Pulse Width Modulation chip <ref>Some manufacturers and corporations will not like our attitude for referring to their integrated circuits as "chips" for sure, but at pawn shops and online auction sites selling jewelry and electronics one should not be ashamed to call them that. We have no opinions on offers of free samples direct from manufacturers or wholesalers, other than that they apparently contact local cops to enforce a litany of unwritten rules and unspoken codes sometimes pertaining to "intellectual property" by which hobbyists as opposed to professionals are supposed to abide.</ref> like the Texas Instruments TL5001AMJG <ref>PWM Controller with wide input range, with ±3% tolerance on reference, operation –55°C to 125°C https://www.ti.com/product/TL5001AM</ref>. These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.

File:SEPIC.pdf

Rational Point — Mon, 13 Apr 2026 23:43:33 GMT

Rational Point uploaded File:SEPIC.pdf

New page

Main Page

Rational Point — Sun, 12 Apr 2026 23:41:33 GMT

Alan Turing straight and narrow

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	[[Image:Elliptic-curve-1.png\|frame\|right\|The elliptic curve		[[Image:Elliptic-curve-1.png\|frame\|right\|The elliptic curve
	<math>y^2=x^3-x^2+\frac 12</math>.]]		<math>y^2=x^3-x^2+\frac 12</math>.]]
			There is cryptography here, the rudimentary framework of it.

	* [[TO DO]]: Reminders, work in progress ...		* [[TO DO]]: Reminders, work in progress ...

			However, life gets in the way. Life is about punishing our enemies, and making them pay for all the trouble and sorrow they have caused us and continue to cause us. The Pagans had a creed, "I will kill all my enemies." Once, having accomplished this, they accepted Christianity, but for a long time now, there is no peace, no rest on Sunday, since others we had thought to be friends and believed to be friends invited our enemies into our churches and usual places of worship to spite us. Perhaps they were ignorant, and perhaps in their ignorance they thought it was some small matter or another for which they could act as "peacemakers" — but no, those enemies really are our enemies, and they really are here to kill us, as that is their creed, on their side of the battle. Some of them wanted others to assume that we were all friends together, but that is not and cannot be the case. No. They bear malice which can no longer be concealed, and that is what bursts forth in open anger once ignorance is ruled out as a cause of their continual troublemaking.

			As an example of troublemaking one might consider the case of Alan Turing's dishonorable bosses and associates who insisted he was gay and tortured him to death on that account. All indications are that Alan Turing was simply much too straight and narrow for that "sort of nonsense up with which we will not put" to paraphrase Winston Churchill.

	== Introduction ==		== Introduction ==

Magnetic permeability

Rational Point — Sun, 12 Apr 2026 15:01:22 GMT

Example problem

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	:''μ'' = ''Lℓ'' / ''N''<sup>2</sup>''A''		:''μ'' = ''Lℓ'' / ''N''<sup>2</sup>''A''

			=== Example ===

			[[File:Inductor 20260412~2.jpg\|thumb\|alt=Measuring inductance\|Measuring inductance\|none]]

			For this example, L=1.813mH, ''Φ''=102mm, ''φ''=65.5mm, A=18.25mm×19.5mm, and N=23.

			Problem: calculate the magnetic permeability of the material of which this core is made.

File:Inductor 20260412~2.jpg

Rational Point — Sun, 12 Apr 2026 14:46:03 GMT

Rational Point uploaded File:Inductor 20260412~2.jpg

New page

Magnetic permeability

Rational Point — Sat, 11 Apr 2026 22:37:14 GMT

harmonic mean path length

New page

== Calculating the magnetic permeability of a toroid core ==

:''L'' = ''μN''2''A'' / ''ℓ''

where ''L'' is the inductance of a winding of wire about a magnetic core, ''μ'' is the magnetic permeability of the core, ''N'' is the number of turns of wire, A is the (constant) cross-sectional area of the core and ''ℓ'' is the harmonic mean path length of magnetic flux through the core. If ''Φ'' is the outer diameter and ''φ'' is the inner diameter of a toroidal core with a rectangular cross section, then the harmonic mean path length is calculated:

:<math>\ell = \pi\cdot\frac{\Phi-\phi}{\int_{\phi}^{\Phi} \frac {dx}x} = \pi\cdot\frac{\Phi-\phi}{\log\Phi-\log\phi}</math>.

Now

:''μ'' = ''Lℓ'' / ''N''2''A''

555

Rational Point — Wed, 08 Apr 2026 15:32:28 GMT

Notes

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			[[File:555-op-amp-ctl.svg\|thumb\|alt=555 op amp demo\|Simple Demonstration Circuit]]

	The '''555''' is a ubiquitous "timer" chip used by electronics hobbyists and experimenters.		The '''555''' is a ubiquitous "timer" chip used by electronics hobbyists and experimenters.

	[[File:555-op-amp-ctl.svg\|~~thumb~~\|~~alt~~=~~555 op amp demo~~\|~~Simple Demonstration Circuit~~]]
			== Clocking the 555 ==
			The simple demonstration circuit depicted above right is probably the simplest external clock for the 555. Below we have hastily constructed a true precision “clock” using four off-the-shelf bipolar transistors and some auxiliary resistors.

			This circuit below operates by charging capacitor C1 through resistor R5 only up to the trigger level of 2/3 the supplied voltage, and then discharging the same capacitor down to the threshold value of 1/3 the supplied voltage through resistor R2 only.

			[[File:555-op-amp-ctl-clock.svg\|frameless\|none]]

			=== Notes ===

			Transistors Q1 and Q4 operating in parallel appear redundant, and it would seem desirable to simplify the circuit to eliminate one of them. We have not determined the best way to do this with a simulated design, however.

			R9 is an arbitrary load resistor for the output, probably less than desirable.

			We have produced a simulated oscilloscope trace using Ngspice <ref>ngspice - open source spice simulator https://ngspice.sourceforge.io/</ref> and/or LTspice <ref>“LTspice® is a powerful, fast, and free SPICE simulator software…” https://www.analog.com/en/resources/design-tools-and-calculators/ltspice-simulator.html</ref> on KiCad <ref>KiCad: A Cross Platform and Open Source PCB Design Suite https://www.kicad.org/</ref>.

			[[File:Plot555-2026-04-06.png\|frameless\|none]]


	[[Category:Electronics]]		[[Category:Electronics]]

File:Plot555-2026-04-06.png

Rational Point — Wed, 08 Apr 2026 14:57:03 GMT

Rational Point uploaded File:Plot555-2026-04-06.png

New page

File:555-op-amp-ctl-clock.svg

Rational Point — Wed, 08 Apr 2026 14:32:11 GMT

Rational Point uploaded File:555-op-amp-ctl-clock.svg

New page

Main Page

Rational Point — Sat, 04 Apr 2026 14:45:04 GMT

TO DO

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	<math>y^2=x^3-x^2+\frac 12</math>.]]		<math>y^2=x^3-x^2+\frac 12</math>.]]

	[[TO DO]]		* [[TO DO]]: Reminders, work in progress ...

	== Introduction ==		== Introduction ==

TO DO

Rational Point — Sat, 04 Apr 2026 14:43:45 GMT

TO DO stuff moved off front page

New page

== TO DO: ==
'''It's a total show-stopper: Get rid of the third-party equation-running services.'''
=== Example error message when editing equations ===
<big><nowiki>Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E=mc^2}</nowiki></big>

* <tt>[https://wikimedia.org/api/rest_v1/ "https://wikimedia.org/api/rest_v1/"]</tt> Huh? What's that for?


Example workaround code is here: <big>'''[[Pure HTML Math]]'''</big> for equations without 3rd-party SaaS or equation-running malware. Please take a look and experiment yourself.


Mathjax and Mathoid or Restbase or related services or funky MathML browser plugins are notorious for containing malicious code and spyware, and hidden calls to third party API services.

Math equations cannot be made up “beautiful” or spread “all over the web” or ripped off or dynamically rendered on other people’s websites. Math equations are highly technical, and they need to be left alone on people's websites, precisely as is, without any extraneous garbage dependencies or third party API services or pop-ups or dollar-sign script-runners or other javascript nonsense called in to dynamically render or display them.

The math jerks and the malicious software math equation web APIs gotta go. Stop running off with all the math equations out the back door!

* https://www.etsy.com/market/hippity_hoppity_get_off_my_property_sign
* https://www.mysecuritysign.com/funny-hippity-hoppity-get-off-my-property-frog-sign/sku-s2-5588
* https://highceeaerials.com/hippity-hoppity-get-off-of-my-property/
* https://threeinfive.com/hippity-hoppity-get-off-my-property-kermit/

Main Page

Rational Point — Sat, 04 Apr 2026 14:42:37 GMT

@@ Line 2: / Line 2: @@
 <math>y^2=x^3-x^2+\frac 12</math>.]]
-== TO DO: ==
+[[TO DO]]
 == Introduction ==

Solar systems

Rational Point — Fri, 03 Apr 2026 15:55:01 GMT

Component selection and Bill of Materials

← Older revision		Revision as of 15:55, 3 April 2026
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	The heart of the controller is a Pulse Width Modulation chip <ref>Some manufacturers and corporations will not like our attitude for referring to their integrated circuits as "chips" for sure, but at pawn shops and online auction sites selling jewelry and electronics one should not be ashamed to call them that. We have no opinions on offers of free samples direct from manufacturers or wholesalers, other than that they apparently contact local cops to enforce a litany of unwritten rules and unspoken codes sometimes pertaining to "intellectual property" by which hobbyists as opposed to professionals are supposed to abide.</ref> like the Texas Instruments TL5001AMJG <ref>PWM Controller with wide input range, with ±3% tolerance on reference, operation –55°C to 125°C https://www.ti.com/product/TL5001AM</ref>. These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.		The heart of the controller is a Pulse Width Modulation chip <ref>Some manufacturers and corporations will not like our attitude for referring to their integrated circuits as "chips" for sure, but at pawn shops and online auction sites selling jewelry and electronics one should not be ashamed to call them that. We have no opinions on offers of free samples direct from manufacturers or wholesalers, other than that they apparently contact local cops to enforce a litany of unwritten rules and unspoken codes sometimes pertaining to "intellectual property" by which hobbyists as opposed to professionals are supposed to abide.</ref> like the Texas Instruments TL5001AMJG <ref>PWM Controller with wide input range, with ±3% tolerance on reference, operation –55°C to 125°C https://www.ti.com/product/TL5001AM</ref>. These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.

	The Littelfuse/IXYS IXFN520N075T2<ref>Littelfuse/IXYS IXFN520N075T2 https://www.littelfuse.com/products/power-semiconductors-control-ics/mosfets-si-sic/n-channel-trench-gate/gen2/ixfn520n075t2</ref><ref>Littelfuse/IXYS IXFN520N075T2 Datasheet https://www.littelfuse.com/assetdocs/littelfuse-discrete-mosfets-ixfn520n075t2-datasheet?assetguid=8706a9d1-94c2-4e6f-8277-46cab5c71388</ref> power MOSFET "trench gate" is essentially rated to handle 480A in the on state and 75V in the off state. The Vishay VS-FC420SA10 <ref>VS-FC420SA10 Product Information https://www.vishay.com/en/product/95793/</ref><ref>Vishay VS-FC420SA10 Datasheet https://www.vishay.com/docs/95793/vs-fc420sa10.pdf</ref> is another brand of power MOSFET rated to carry 435A when on or hold 100V when off. It comes in the same form factor, an SOT-227 which looks and acts like a miniature clothes iron, and requires an excellent heat sink rated for switching losses and forward voltage drop at the rated current. It would appear that if either of these devices functions as advertised, you could easily start an automobile with the electric current they are rated for handling if you wired one of them up in place of a solenoid for the starter motor.		The Littelfuse/IXYS IXFN520N075T2<ref>Littelfuse/IXYS IXFN520N075T2 https://www.littelfuse.com/products/power-semiconductors-control-ics/mosfets-si-sic/n-channel-trench-gate/gen2/ixfn520n075t2</ref><ref>Littelfuse/IXYS IXFN520N075T2 Datasheet https://www.littelfuse.com/assetdocs/littelfuse-discrete-mosfets-ixfn520n075t2-datasheet?assetguid=8706a9d1-94c2-4e6f-8277-46cab5c71388</ref> power MOSFET "trench gate" is essentially rated to handle 480A in the on state and 75V in the off state. The Vishay VS-FC420SA10 <ref>VS-FC420SA10 Product Information https://www.vishay.com/en/product/95793/</ref><ref>Vishay VS-FC420SA10 Datasheet https://www.vishay.com/docs/95793/vs-fc420sa10.pdf</ref> is another brand of power MOSFET rated to carry 435A when on or hold 100V when off. It comes in the same form factor, an SOT-227 which looks and acts like a miniature clothes iron, and requires an excellent heat sink rated for switching losses and forward voltage drop at the rated current. It would appear that if either of these devices functions as advertised, you could easily start an automobile with the electric current they are rated for handling if you wired one of them up in place of a solenoid for the starter motor. As far as we can tell, this can actually be done, except that the high power MOSFETS require 10V to drive the gate, and the drawdown on a 12V car battery from the starting current will reduce the voltage below the gate actuation level.

			Insulated-Gate Bipolar Transistors (IGBTs)<ref>Insulated-Gate Bipolar Transistors (IGBTs) https://toshiba.semicon-storage.com/us/semiconductor/knowledge/e-learning/discrete/chap3/chap3-16.html
			</ref><ref>Comparison of Forward Characteristics of IGBTs and MOSFETs
			https://toshiba.semicon-storage.com/us/semiconductor/knowledge/e-learning/discrete/chap3/chap3-21.html</ref> are another option for the high power current switching needed for the Buck-Boost or SEPIC controllers that need to be used for regulating the voltage from variably sunlit photovoltaic cells to a usable level.

			[[Category:Electronics]]

	== Batteries ==		== Batteries ==
	tbd ...		tbd ...

555

Rational Point — Fri, 03 Apr 2026 04:50:59 GMT

demo

New page

The '''555''' is a ubiquitous "timer" chip used by electronics hobbyists and experimenters.

[[File:555-op-amp-ctl.svg|thumb|alt=555 op amp demo|Simple Demonstration Circuit]]

[[Category:Electronics]]

File:555-op-amp-ctl.svg

Rational Point — Fri, 03 Apr 2026 04:47:50 GMT

Rational Point uploaded File:555-op-amp-ctl.svg

New page

File:Ss-2.svg

Rational Point — Thu, 02 Apr 2026 16:46:31 GMT

Summary

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	== Summary ==		== Summary ==
	Another model using the LM51561H		Another model using the LM51561H

			Very sketchy. We have not had success running the official SPICE simulation distributed with this product.

			It is a very delicate surface mount chip about 5mm×6mm with 14 pins spaced at a 0.65mm pitch, and requiring a heat sink. Another version is 2mm×3mm and has 12 surface mount solder pads with a 0.5mm spacing.

			We are not dealing with very high frequencies and we would prefer to avoid chips that are so tiny and delicate.

			However, for those who know what they are doing and have the knowledge and experience to make these things work, they might be just fine, assuming they do function as documented.

Solar systems

Rational Point — Thu, 02 Apr 2026 16:34:05 GMT

Component selection and Bill of Materials: alternative power MOSFET

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	==Charge controller==		==Charge controller==
	[[File:Ss-1.svg\|alt=Solar Cell System with Charge Controller and Battery\|thumb\|Solar Cell System with Charge Controller and Battery]]		[[File:Ss-1.svg\|alt=Solar Cell System with Charge Controller and Battery\|thumb\|Solar Cell System with Charge Controller and Battery (using TI TL5001AMJG)]]
			[[File:Ss-2.svg\|alt=Solar Cell System with Charge Controller and Battery\|thumb\|Solar Cell System with Charge Controller and Battery (using TI LM51561HPWPR)]]

	We find that off-the-shelf charge controllers are over-rated and overpriced, and we propose building one from scratch with adequate safety margins for high household power requirements.		We find that off-the-shelf charge controllers are over-rated and overpriced, and we propose building one from scratch with adequate safety margins for high household power requirements.

	A Buck-Boost Converter<ref>Buck-Boost Converter: What is it? (Formula and Circuit Diagram) https://www.electrical4u.com/buck-boost-converter/</ref> or Single-Ended Primary Inductor Converter (SEPIC)<ref>SEPIC Converters https://www.monolithicpower.com/en/learning/mpscholar/power-electronics/dc-dc-converters/sepic-converters</ref><ref>Dongbing Zhang. "AN-1484 Designing A SEPIC Converter." Application Report SNVA168E – May 2006 – Revised April 2013. https://www.ti.com/lit/an/snva168e/snva168e.pdf </ref> is typically used for this purpose.		A Buck-Boost Converter <ref>Buck-Boost Converter: What is it? (Formula and Circuit Diagram) https://www.electrical4u.com/buck-boost-converter/</ref> or Single-Ended Primary Inductor Converter (SEPIC) <ref>SEPIC Converters https://www.monolithicpower.com/en/learning/mpscholar/power-electronics/dc-dc-converters/sepic-converters</ref><ref>Dongbing Zhang. "AN-1484 Designing A SEPIC Converter." Application Report SNVA168E – May 2006 – Revised April 2013. https://www.ti.com/lit/an/snva168e/snva168e.pdf </ref> is typically used for this purpose.

	An inductor, coil or transformer may be wound by hand using a adequate gauge of thinly insulated Tefzel or similar wire on a used or salvaged laminated or powdered iron core. The core of a transformer or inductor, if not powdered cerrite, must be made of thin layers of soft tempered malleable iron or mild steel that will swing the needle of a compass, and it should never be "quenched" or "saturated." The laminated iron core should be "tanned" with oak gall and waxed with beeswax and/or lacquered with boiled linseed oil to form insulative layers of oxide and wax or lacquer between the layers of steel, so that the transformer will not short out between the layers of steel and melt down under load. The windings of wire on a homemade transformer or inductor should be of the purest copper, smoothly drawn, carefully annealed to a soft temper, ductile, and flexible, with the best quality of insulation that is not too thick. Take care that wire windings are smooth and not bent or creased on sharp corners.		An inductor, coil or transformer may be wound by hand using a adequate gauge of thinly insulated Tefzel or similar wire on a used or salvaged laminated or powdered iron core. The core of a transformer or inductor, if not powdered cerrite, must be made of thin layers of soft tempered malleable iron or mild steel that will swing the needle of a compass, and it should never be "quenched" or "saturated." The laminated iron core should be "tanned" with oak gall and waxed with beeswax and/or lacquered with boiled linseed oil to form insulative layers of oxide and wax or lacquer between the layers of steel, so that the transformer will not short out between the layers of steel and melt down under load. The windings of wire on a homemade transformer or inductor should be of the purest copper, smoothly drawn, carefully annealed to a soft temper, ductile, and flexible, with the best quality of insulation that is not too thick. Take care that wire windings are smooth and not bent or creased on sharp corners.
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	The heart of the controller is a Pulse Width Modulation chip <ref>Some manufacturers and corporations will not like our attitude for referring to their integrated circuits as "chips" for sure, but at pawn shops and online auction sites selling jewelry and electronics one should not be ashamed to call them that. We have no opinions on offers of free samples direct from manufacturers or wholesalers, other than that they apparently contact local cops to enforce a litany of unwritten rules and unspoken codes sometimes pertaining to "intellectual property" by which hobbyists as opposed to professionals are supposed to abide.</ref> like the Texas Instruments TL5001AMJG <ref>PWM Controller with wide input range, with ±3% tolerance on reference, operation –55°C to 125°C https://www.ti.com/product/TL5001AM</ref>. These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.		The heart of the controller is a Pulse Width Modulation chip <ref>Some manufacturers and corporations will not like our attitude for referring to their integrated circuits as "chips" for sure, but at pawn shops and online auction sites selling jewelry and electronics one should not be ashamed to call them that. We have no opinions on offers of free samples direct from manufacturers or wholesalers, other than that they apparently contact local cops to enforce a litany of unwritten rules and unspoken codes sometimes pertaining to "intellectual property" by which hobbyists as opposed to professionals are supposed to abide.</ref> like the Texas Instruments TL5001AMJG <ref>PWM Controller with wide input range, with ±3% tolerance on reference, operation –55°C to 125°C https://www.ti.com/product/TL5001AM</ref>. These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.

	The Littelfuse/IXYS IXFN520N075T2<ref>Littelfuse/IXYS IXFN520N075T2 https://www.littelfuse.com/products/power-semiconductors-control-ics/mosfets-si-sic/n-channel-trench-gate/gen2/ixfn520n075t2</ref><ref>Littelfuse/IXYS IXFN520N075T2 Datasheet https://www.littelfuse.com/assetdocs/littelfuse-discrete-mosfets-ixfn520n075t2-datasheet?assetguid=8706a9d1-94c2-4e6f-8277-46cab5c71388</ref> power MOSFET "trench gate" is essentially rated to handle 480A in the on state and 75V in the off state.		The Littelfuse/IXYS IXFN520N075T2<ref>Littelfuse/IXYS IXFN520N075T2 https://www.littelfuse.com/products/power-semiconductors-control-ics/mosfets-si-sic/n-channel-trench-gate/gen2/ixfn520n075t2</ref><ref>Littelfuse/IXYS IXFN520N075T2 Datasheet https://www.littelfuse.com/assetdocs/littelfuse-discrete-mosfets-ixfn520n075t2-datasheet?assetguid=8706a9d1-94c2-4e6f-8277-46cab5c71388</ref> power MOSFET "trench gate" is essentially rated to handle 480A in the on state and 75V in the off state. The Vishay VS-FC420SA10 <ref>VS-FC420SA10 Product Information https://www.vishay.com/en/product/95793/</ref><ref>Vishay VS-FC420SA10 Datasheet https://www.vishay.com/docs/95793/vs-fc420sa10.pdf</ref> is another brand of power MOSFET rated to carry 435A when on or hold 100V when off. It comes in the same form factor, an SOT-227 which looks and acts like a miniature clothes iron, and requires an excellent heat sink rated for switching losses and forward voltage drop at the rated current. It would appear that if either of these devices functions as advertised, you could easily start an automobile with the electric current they are rated for handling if you wired one of them up in place of a solenoid for the starter motor.

	== Batteries ==		== Batteries ==
	tbd ...		tbd ...

File:Ss-2.svg

Rational Point — Mon, 30 Mar 2026 15:30:23 GMT

Rational Point uploaded File:Ss-2.svg Another model using the LM51561H

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== Summary ==
Another model using the LM51561H