F4A33 kiggly mod diode question

[DannyE]

Hey fellas, I have a quick question regarding the kiggly manual matic mod for the F4a33 trans. I know I need 2 amp diodes but what about volts? When I go to purchase diodes in 2 amps they offer a wide range of volts. A majority of the 2 amp diodes are 800 volts, just want to make 100% sure before making a purchase. I searched all over but just could not find it.

Thanks in advance for all of the help.

 

[steve]

Your working with blocking 12v via the diode so the voltage rating isn't too critical any of the 1N540X diodes should be fine. The key spec Kiggly gives is that it needs to be at least a 2A diode for the common 1N400X series wont cut it.

 

[DannyE]

I see, well my local radio shack has some FR207 fast recovery 2amp 1000v diodes. Was just wondering if these will be fine or not?

I’m pretty sure that they will work but better get an experts advise before pulling the trigger

I appreciate all the help man.

 

[bastarddsm]

Yes the probably should.

I was just checking to see if they are freewheeling diodes. Doesn't look like it. I would probably go for the 1000V because of back emf.

 

[DannyE]

@bastarddsm ok, so the fr207 2amp 1000 volt ones should be fine? I mean there cheap so if they don’t work at least it’s not to much wasted, well except time .

Thanks for the help bro.

 

[bastarddsm]

Yes I would suspect they should be fine. My inquiry was due to the voltage spike that occurs when you de-energize a solenoid. Prudent practice would to be to put a diode backwards across the soilenoids - a freewheel diode. A google search will explain the idea.

Anyway as far as things go, it's generally acceptable to use a diode with a higher rating than you need, current and voltage. Except a zener diode.

 

[DannyE]

Yeah that’s what I read as well, I guess the fr207’s will do then.

Thanks again for all of the help bud.