Homemade diode block, XJ650J

After testing the diode block on my 650J I have determinded that at least one of the diodes are bad. (No continuity between W and W/G, regardless of polarity).

With diodes no more $0.05 each I can't justify buying an actual diode block.

How much current do these diodes need to handle? Can I use a 4n4001 or similar?

I have seen a few threads discussing a DIY diode block, but noone mentioned success.

Any thoughts?

 

If it helps, I think the alternator is rated for 19 amps output.

 

For a whopping 64 cents each you could use a FR601 package (or the 604 or 606 but I think they are overkill). They are a larger package (not the DO-35 everyone sees everywhere). I was unable to find the 4N4001 at any source I know of (findchips.com is your friend). Wikipedia mentions it as a 1 amp silicone power rectifier but I think that is a mite too small in current rating. Could you furnish a data sheet on it? I'll talk to my engineers at work about whipping up a replacement and the correct diode to use. Stay tuned...

 

Robert,
1 amp sounds about right.
http://www.tnw.utwente.nl/onderwijs_ove ... 1n4007.pdf

1amp, 50v

I don't see anything in the Haynes wire diagram that looks like it needs much power. Mainly relays, etc. They shouldn't need even an amp.

 

digikey # 36MT10-ND
all in one chip

 

I just talked to my engineers and they agreed, the 1N4001 would work fine but in the event you can't find it, the 1N4004 at Digikey is running 0.07 apeice for 10 and will work just fine (higher voltage rating but still the same part).
I thought that a higher current rating would be a better idea (i.e. build it overkill!). The coil current on a standard auto relay needs only a few hundred milliamps so even 5 relays could be served by a 1 amp part.
Polock, I don't have my diode block schematic handy so I'll look at your part suggestion tonight, it sounds like a great idea (if it is wired to our needs).

 

Won't work, at least if you want to make something plug compatible - It's a bridge rectifier and the diode block is not. The diode block (on a 650J) is 3 diodes and a resistor. Should be easy to replace with discrete parts.

On some bikes (some 750s) it is a single diode and on 650G it is 2 diodes and a resistor.

I haven't traced the schematic to see how the diodes are used exactly but doesn't matter if you want to build a compatible unit.

 

Thanks guys. I was going to pick up the parts at work#1 today, but I got busy and forgot. I've got to study for a test over the next few days. Hopefully I'll get this done before the weekend. I'm also going to try to encase it in rosin/epoxy, similar to the OEM part.

 

I would encase it once you have it working it will protect the assembly.

 

Ahh, not enough hours in the day.

Just realized I posted the link to the wrong diode... a 4001 is a 1amp, 50v diode.

Just for fun I tried holding one against the correct contacts in my headlight bucket and it worked great. So maybe (ha!) tomorrow I can build a new diode block.