https://revspace.nl/wiki/index.php?action=history&feed=atom&title=PowerInductorTester 2026-05-13T09:50:30Z Revision history for this page on the wiki MediaWiki 1.43.6 https://revspace.nl/wiki/index.php?title=PowerInductorTester&diff=29824&oldid=prev 2022-06-20T21:36:48Z

<p>Created page with &quot;{{Project |Name=Power Inductor Tester |Picture=ProjectCoilTesterClickbait.jpg |Omschrijving=test inductors to find their saturation current and inductance-current character...&quot;</p> <p><b>New page</b></p><div>{{Project<br /> |Name=Power Inductor Tester<br /> |Picture=ProjectCoilTesterClickbait.jpg<br /> |Omschrijving=test inductors to find their saturation current and inductance-current characteristic.<br /> |Status=In progress<br /> |Contact=AlexanderB<br /> }}<br /> <br /> <br /> <br /> == What ==<br /> Inductors are often specified with just one inductance figure, but in reality their behaviour is non-linear. <br /> <br /> Once an inductor goes into saturation, the inductance decreases quite drastically.<br /> <br /> This is especially important for power inductors in DC-DC converters, as going into saturation can lead to magic smoke escaping.<br /> <br /> This also makes it possible to test and characterize self-built coils, or coils of unknown origin for which no datasheet exists.<br /> <br /> Perhaps not as useful for the people looking to quantize frequency response, but the space has a signal generator for that.<br /> <br /> == Hardware ==<br /> The project is based on an existing project that I found here:<br /> <br /> https://ludens.cl/Electron/lmeter/lmeter.html<br /> <br /> and similar to the one here:<br /> <br /> http://elm-chan.org/works/lchk/report.html<br /> <br /> <br /> I&#039;ve posed myself the extra challenge of making it fit inside of a peppermint tin.<br /> <br /> === Schematic ===<br /> [https://ludens.cl/Electron/lmeter/LMETERsmall.png|Original schematic from Ludens]<br /> <br /> And my own version ---&gt;<br /> <br /> [[File:PowerInductorTesterSchematic.jpeg|thumb|My own schematic in KiCAD]]<br /> <br /> === Component Selection ===<br /> Mostly identical to the original schematic.<br /> <br /> Capacitors are 30x 1500uF Low ESR. <br /> <br /> A mix of SMD and THT parts to optimize for board space.<br /> <br /> === PCB ===<br /> Partly drawn up, I want to verify the components fitting in the enclosure before I finalize the design though.<br /> <br /> == Usage ==<br /> Solder the silicone leads to the legs of the inductor under test. This provides lower resistance than connecting with any kind of clamp.<br /> <br /> Set the tester to it&#039;s lowest setting<br /> <br /> Connect the BNC connector to an oscilloscope.<br /> <br /> Connect the meter to a lab power supply set to 10 volts, current limited to 1 amp.<br /> <br /> Turn up the tester until the saturation point is visible on the scope.<br /> <br /> === Tiny inductors ===<br /> Start with the tester pulse time very low, otherwise it&#039;s quite possible to blow up very tiny inductors with too strong of a current peak.<br /> <br /> === Big inductors ===<br /> The tester should be capable of saturation current of 100A. Higher currents (&gt;60A) may require the power supply be increased to 12V and up to 3A. <br /> <br /> This will also overheat the tester, so don&#039;t leave it running at 3A.<br /> <br /> === Math ===<br /> I refer you back to the original until I write an explanation myself.<br /> <br /> https://ludens.cl/Electron/lmeter/lmeter.html<br /> <br /> Every millivolt on the scope is 1 amp of current in the inductor. <br /> <br /> The slope of the trace can be calculated to the inductance value at that current.<br /> <br /> == And now? ==<br /> I&#039;m making two, so I can loan/donate one to the space so others can use it at any time.</div>

AlexanderB