Alternator circuit - still not working. Why...
 

Hi Guys,

I just finished of my DIYPNP and made a stupid electronics rookie mistake.

I swapped the +/- sides of the big capacitor 25V 100uF and the thing went PLOPP! :facepalm:

Stupid bloody unnecessary mistake...

The DIYPNP works normal (re-flashed the firmware, loaded the MSQ, sent all the sensor calibrations.)

The alternator circuit though doesn't do what he is supposed to. What did I fry within the circuit?

https://www.miataturbo.net/forum/att...alternator.png

Of course I changed the Cap to a new one with the right direction...

Thanks - Greets

the e-rookie
Sven

Nobody? I just need to now, what of the parts of the probably have been killed, that prevent the circuit from working.

The transistors? the 2 small capacitors? The resistors? All?


Thanks

I don't think the capacitor would cause something else to blow (except maybe a copper trace on the board because of too much current). If anything, the 2907's are a candidate so you might want to do a diode test on them. Clicky. First, I'd triple check if you built the circuit correctly though.
If you still have my circuit, you could compare voltages on different points of the circuit.

Thanks Frank, that is at least a hint.
I checked the circuit really careful and it should be correct.

I have enough parts to build another one - so I may build another one on a little piece of extra-board and test it first, then adapt it to the DIYPNP board.

I tested your board too (btw. you did forget to make one connection on the alternator circuit) and it should give me the hints, how the voltages should read.

Greets

Hi Frank and all,

I built a new little circuit (I copied your circuit 1:1).

When I have +12V and ground attached I get a similar voltage between the field and ground - varies with voltage input-higher input higher voltage at the field, also with lesser voltage.

But I cannot get a current reading (neither with your or my circuit - I know I already got a reading with yours) Am I doing something wrong?

Greets

that's odd, as I tested the alternator circuit on the workbench, and it worked fine. IIRC, the output followed the input up to 14.3V, above that, the output dropped to zero.
I did not test the other circuits on the board though (can't remember what they were though, fan output or so?)

I had issues when I first built mine because I didn't use 1% resistors. This thread might be of help.

There was no connection between C2 an R3, they both ended in a single spot.

I just tried your circuit with my laptops cable 19V - seems to work. No reading at the field.
I haven't got a adjustable power source.

Greets

I spent a good amount of time on this, but I think I found your problem. Your cicuit should look like this.

WTF? What should this be?

Oh, O.k. haha. See, I laughed. Now go play with yourself.

I seriously think this could be interesting for the DIYPNP 99-00 guys.

Sjees, you actually spend your time just to insult people. Nice. Now run along.

You Europeans need to loosen up a little. Its a damn joke.

I thought the jokes belong to the <insert BS here> corner... ;)

We Germans never laugh - we always start wars about those little things... :fawk: