For shopping similar diodes, the IN400X series are all 1 amp, 30A
surge rectifier diodes. IN4005 is 600 volts, IN4006 800V, IN4007
1000V. Here's discussion of the potential problem:
http://www.leachintl2.com/english/english2/vol6/properties/how7.htm
They say probably a 750V spike, but could be 3,000V, but on 28V system
in an airliner. One-half thereof may be valid for 14V, but on the
scope it looks like a few hundred on a relay we would use. If a diode
is there and it's working, I have trouble picturing there's any high
voltage across it, just some response time effect (the spikes are
really skinny).
But in any event, it doesn't follow that a millisecond shot to the
diode above the reverse volts rating kills it. Besides some Zener
effect, the data sheet says add 20% for isolated voltage events, but I
could not get some 100V 1N4002's to avalanche even at 200V. So 1KV
diodes are cheap and common, e.g., Radio Shack P/N 276-1114, a PTC205
3-amp'er. Or 1N5407.
Regards,
Fred F.
Mike Gregory wrote:
>
> The 1N4000 series diodes show their peak inverse voltage rating (ie the max
> 'spike' they can take) according to the final digit. This gives the rating
> in hundreds of volts: 1N4005 should stand 500v without failure. So the
> 1N4006 at 600v would be OK, but the 1N4001 to 1N4004 series might break down
> in an application such as this where 1N4005 is recommended. Any higher
> rating would be suitable, but the lower-rated diodes should not be placed in
> series in an attempt to achieve a higher rating. Additional diodes in
> parallel are unlikely to be a problem, provided they are each of adequate
> rating.
>
> Fly safely
>
> Mike Gregory
> Europa Club Safety Officer
> m.j.gregory@cranfield.ac.uk
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