Diode question

JackConrad · February 18, 2009, 10:56:27 AM

I want to install a diode on a solenoid to prevent any voltage spikes when solenoid is de-energized. I cannot find my notes I saved on this subject, so I have 3 questions:
1. Which terminal on the solenoid does the diode connect to?
2. Does other end of diode connect to ground?
3. Diode is black with a white ring around one end. Which end of diode connects to what?
Thanks, Jack

WEC4104 · February 18, 2009, 11:08:31 AM

The following link has the info I think you are looking for...

http://www.kpsec.freeuk.com/components/diode.htm

... about halfway down the page there is a discussion of using diodes to protect electronics connected to relays.

Don4107 · February 18, 2009, 12:12:03 PM

The diode is connected across the coil with the cathode, or banded end hooked to the positive activation lead. This is for a negative ground system.

1. Which terminal on the solenoid does the diode connect to?

The cathode or banded end connects where you have connected the activation lead, be it 12 or 24 volts.

2. Does other end of diode connect to ground?

The other end, or anode, connects to the other end of the activation coil whether it is a separate terminal on the relay or ground if the relay has an internal ground.

3. Diode is black with a white ring around one end. Which end of diode connects to what?

See above.

rv_safetyman · February 18, 2009, 12:16:24 PM

Jack, on a relay the diode is placed across the two signal wires. The diode arrow points towards the positive side. I would assume it would be the same with a larger relay (solenoid).

Our resident expert (Sean) is basking in Hawaii off line. He may answer when he gets back.

Jim

wrench · February 18, 2009, 01:33:26 PM

I can tell you, if that diode is not connected on HD starter it will hang on till the starter is toasted or battery dead.
wrench

JackConrad · February 18, 2009, 02:43:58 PM

Thanks guys. That is what I needed. Jack

David Anderson · February 18, 2009, 07:14:48 PM

Here is another picture:

http://www.busconversions.com/bbs/index.php?topic=6186.0

David

David Anderson · February 18, 2009, 07:20:12 PM

I reread these answers. Mine is not hooked to the coil. It is hooked to the battery cabling. Click on the link I posted above and go to page 2 and look at Tim Stroman's drawing. Are we all talking about the same wiring???

David