Is there a simple way to convert a PWM(-) or ground to a PWM(+) or 12-14v signal? .. #2

Thread Starter

randallc79

Joined Sep 17, 2022
10
All You need is a "P-Channel" MOSFET, and 1 Resistor.

This FET is way over-kill, on purpose,
this will allow it to withstand wiring "mistakes", without getting instantly smoked.

You will also need to physically protect it, Heat-Shrink-Tubing will work great.

All Connections must be Soldered.

If this setup is used to Switch a significant Load, ( more than around 1-Amp ),
then it must be mounted to some sort of Heat-Sink,
like an Aluminum-Project-Box.

For more than a ~15-Amp Load, a heavier FET, and a proper Heat-Sink, should be selected.
Motor-Loads will need additional RFI noise protection.
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View attachment 269769
Thank you! This helped a lot trying to figure out ideas to get my Holley Terminator X Max (PWM-) signal for the speedo converted to an aftermarket Speedo Gauge! Holley told me I would need a solid state relay (15620NOS) to be able to do this (this honestly looks like what they did). But after seeing this, going to give this a try first for sure! Also 3D Printed an enclosure for it as well, just to be safe added a small (raspberry pi) heat sink. I had laying around as well. Any idea on what Pulse Per Mile, I should use in the Holley settings? I know it's currently defaults to 4000 (4k). Holley's 15620NOS say's it can only handle 1k, I'm just not spending the $80 to break it open and see.
 
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Wendy

Joined Mar 24, 2008
23,057
Looked like you were asking a question on someone else's thread, that is the very definition of hijacking.
 

Thread Starter

randallc79

Joined Sep 17, 2022
10
Looked like you were asking a question on someone else's thread, that is the very definition of hijacking.
I was asking if they had ran across that with their issue. PWM and PPM are so similar they could technically be two ways of saying the same thing. I had no intention on hijack anything from their thread, if anything it would have added value to it.
 

Thread Starter

randallc79

Joined Sep 17, 2022
10
@LowQCab @TimC787 Just wanted to say THANKS! @TimC787 your original post that got me wondering if and how you were using that mosfet would work with my application regarding holley's terminator x max. AND a even bigger thanks to @LowQCab for the help with part numbers and simply diagram to solder everything up!

I just tested using this to convert Holley's PWM- (speedo output), to GlowShift Speed'o'Meter. Using Holley's Default 4000 ppm (setting in the terminator x max) and Setting the GS-Speed'o to Switch 2 (1998 ~ 9999 PPM) then with some slight tweaking to the Speedo's calibration. Worked like a champ and the mosfet (using 18gauge wire) can't even feel it getting hot either.

Documenting all this so anyone else with Speedo output from Holley terminator will have some guidance!

Parts:
https://www.digikey.com/en/products/detail/ixys/IXTH50P10/1652486
https://www.digikey.com/en/products/detail/vishay-dale/CMF55500R00FEBF/3621957
https://www.digikey.com/en/products/detail/wakefield-vette/CD-02-05-247/7070009

Attaching my test build, before I 3D-Print an enclosure.
20220922_171700.jpg
 
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