Late at night, by candle light, Eeyore
penned this immortal opus:



"John E." wrote:

Ah, another ITT diode on the board starts with "ZY" (where "Z" could be
mistaken for a "4" on the charred carcass). So I looked up ZY47 and get a
4.7v power zener diode, 2W.

http://www.allcomponents.ru/diotec/zy47.htm

Also, according to a National data sheet I found, a 1N4147 (a.k.a. 1N914A) is
glass, and way too lightweight physically compared to my charred sample.
Wrong turn, I think.

So it looks like ZY47?

BZY47-C47?

2 watt zener 47V ? The number after the C is the voltage. 4.7 volts would be
BZY47-C4V7 btw.

Graham

Spot-on I think. It'll normally have 42 V across it, not enough to
conduct. When de-energizing there'll be a spike wich it clamps at 47
V. Dunno why the 1 uF cap.

- YD.

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