Subject: [Amps] Bias Zener Diodes In Parallel ?
> I have an amp that I have put several 5.6Volt @ 5watt zeners
> in series for cathode bias. They get way too hot with
> about 800ma of current. Can I parallel zeners to divide the
> current without problems with balance between them?
>
> Doug, N4IJ
Hi Doug,
I have been doing for years as Henry and other Commercial
amp makers do; I use 50 watt zeners on a heat sink, and have
no problems. They are available from R.F. Parts, Henry Radio,
And K2IW's Silicon Alley.
There is a cheaper approach shown in some of the older ARRL
Handbooks that use a smaller zener in conjunction with a power
transistor, but that just complicates matters and adds vulnerable
parts to the circuit, IMO.
Circa 1982, I quit using glass tubes, diode strings, electrolytic
capacitors, and carbon resistors. Life has been so much more
enjoyable since, with 99% of my hobby time free for operating.
(((73)))
Phil, K5PC
(((73)))
Phil, K5PC
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