Joined: 12 Dec 2008
Location: Erie PA.
|Posted: Tue Oct 25, 2016 6:49 pm Post subject: DIY Automotive oscilloscope probes.
|I always wanted an automotive Oscilloscope, now that I'm older I figured I'd just buy one. I really liked in the old days how we would show all of the secondary ignition patterns at one time and be able to compare them(parade).
Now most cars have a coil per cylinder and most of them are driven internally so the sensible choice was inductive pickups since the old style scopes aren't well suited to COP systems.
There are a few Inductive pickups out there but the cheap ones don't have a reputation for working and the nice ones are pretty pricey considering I wanted 8 of them.
After some research I found an 8 channel scope interface for PC (and I use it with the portable:http://forum.hackedgadgets.com/viewtopic.php?t=2006) that was inexpensive so I followed a non-working diagram (smart huh?)that I found online and tweaked the circuit until it worked.
Ultimately I ended up with 8 inductive scope probes and a Hantek 1008c, the Hantek isn't exactly a piece of precision equipment but for automotive use it's just fine and has already diagnosed a couple of cars.
My Hantek came with an inductive probe but as predicted it didn't work.
The diagram below is my version that works, at some point I may put a couple small variable resistors in them so I can tune them all precisely the same but as of now I can't see any difference in them in the patterns.
My total investment was $200 US give or take a couple bucks.
Use this information at your own risk, I assume no liability for anybody else's project or equipment.
The only foolish question is one that is left unasked.