Zener Diode

Hi
I'm in need of a 18 Volt 5 Watt Zener diode, I have only 18 Volt 1 Watt Zener diodes. My question is, can I put 5 one Watt Zener diodes parallel to make it 5 Watt
?
Thank you in advance Gerhard.
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The short answer is no: the first to fire will take the entire load.
You can do some form of balancing by adding series resistance to each zener, but that loses the voltage stability you want.
Use the zener to establish the voltage at the base of a 5 watt power transistor, and use the emitter as your stablized voltage source.
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Tony wrote:

Or the OP could put half a dozen 3v 1W zeners in *series* to produce the desired voltage.
Or use a three terminal regulator eg LM7818.
etc..
--
Sue



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