At 08:12 10/10/01 Wednesday, G3OLB wrote:
I recently opted for the 'Palstar PS-50' from Nevada which is a linear
PSU giving 40 amps continuous, 50 amps intermittent, at 13.8V. It is big
and heavy but economically priced and no noise. At least, there is no
electrical noise but a slight audible hum from the transformer -
something which you need to consider with a linear supply; a buzzing PSU
can drive you nuts! One with a toroidal transformer should be quieter
than one with a laminated one.
Tom, I also have one and it's fine until it gets a little hot and the fan
cuts in. Then it sounds like a jet taking off. I played with it quite a
bit and eventually found that the best way round it was to rewire so the
fan runs all the time on a reduced voltage just barely enough to start it
and run - about 9volts. That creates enough draught that the heatsink
never gets much more than warm and the fan never needs to run at full
power. Howver, I left the heat sensor connected so if it gets really hot it
a relay switches it onto full 28v, but that has never happened yet even at
25A continuous.
Walter G3JKV.
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