hey, I need help IDing a Zener diode. it has a glass body, black ring on one end, and the marking "47B" in very small letters. I need to know what the stats are on this thing. what I'm TRYING to find is a 4.7V, 400mW Zener for a project. (Nixie clock, actually) and if this is one, great, 'cause I can't get them at Rat shack, and I really don't feel like ordering .40 worth of diodes and paying shipping from jameco. My google-fu has failed me. help me bit-techians. you're my only hope.
Do you have any voltage regulators that are near/above that voltage? If the load resistance does not change much and does not draw much current, you could create a voltage divider. Do you have a local Fry's Electronics?
here's the schematic I'm trying to follow it's Diode D1 (upper left corner, to the right of the 220V rectifier)
That's a rather dangerous design, generating 220V DC from US mains with a voltage-doubler (or using rectified UK 230V) and using R1 & R2 (to spread the waste heat produced over two resistors) and the zener to get the 4.7V supply for the chips. A normal 7805 regulator won't handle that ingoing voltage, safe way is to use a small 9V transformer, rectifier bridge, smoothing and 7805 to produce 5V DC to run the chips. Otherwise find a 4.7V zener and don't assume anything is safe to touch.
generally the numbers on zener diodes dont have anything to do with output voltage, for future reference. (at least on all ive come in contact with at school)
