1N4934 as Zener?

[Nixie]

Can I use a 1N4934 as a 100 V reference?

[wrenchone]

The vast majority of 1N4934 diodes will not break down anywhere near 100V, as this is merely the guaranteed PIV. When the diode does break down, there is no guarantee whatsoever regarding noise or stability. You would be far better off with something like a 1N4764, which is a real 100V, 1W zener diode. Y

[Nixie]

1N4764 must be a pretty rare beast, as even Digikey doesn't have it in stock.

[EchoWars]

3 x 33V zeners perhaps...?

[lineup]

Originally posted by Nixie
Can I use a 1N4934 as a 100 V reference?

Originally posted by wrenchone
You would be far better off with something like a 1N4764, which is a real 100V, 1W zener diode. Y

1N4934 can only be used as a bad 1 volt reference.
As told, 1N4764 is a 100 volt zener-diode, which you can use.
As well as, using 3 x 33 volt, zener diode in series.
This last is what we often find in good electronic circuits for audio ( Nelson Pass ).


Here is an article on the subject of
High Voltage References.
Even if this article is good reading for tube, valve people
it also shows howto use solide state transistors,
to get a nice higher voltage reference.

High Voltage References

There are three main types of high-voltage references:
... a high-voltage zener diode
... a "pseudo-zener" based on a low-voltage reference
... and a gas breakdown tube.

Zener diodes come in voltages as high as 200V, but are more commonly seen up to 75 or 100V. If higher voltages are needed, zeners can be strung in series.
The primary problem with high-voltage zeners is that they have a constant positive temperature coefficient of around 0.1% per °C.

Weblink: http://www.tubecad.com/june2000/page3.html


Lineup Audio & High Voltage References Ltd
Zener Street 100
London

[wrenchone]

Mouser has the 1N4764 in stock. Using 3X 33V zeners in series may give you a lower incremental impedance than the single 100V device (good thing - better regulation) - check the spec sheets to be sure. Using 2X51V would be another option. If you want the pretty glow, you could also use an 0B2 VR tube. If you decide to synthesize an active reference, the possibilities are endless.