[AMPS] Power Supply Progress & a question

[km1h@juno.com]

You forgot to mention the transformer ratings...........
Readings are meaningless without a KVA reference.

73  Carl  KM1H



73  Carl  KM1H

On Fri, 19 Mar 1999 05:27:43 GMT kf4kl@ipass.net (Doug Hall) writes:
>
>Greetings all,
>   Tonight I finally did some load testing on the power supply I'm
>building for my homebrew amp project. (Pair of 3-500Zs.) The supply is
>a full wave design with capacitor input (16uF 7500v oil filled), and
>produces 3900v with no load. I can adjust this up or down some by
>changing taps on the primary.
>   I've got a resistive load (buncha big resistors) that I used for
>testing, and by shorting out various resistors I can vary the load.
>When I connect a 4K ohm load to the DC output the voltage drops from
>around 3900v no-load to 3250v. At this point the current is a little
>over 0.8A. If I decrease the load R to 3500 ohms, the voltage drops to
>around 3200v for a current of just over 0.9A. The secondary voltage
>drops about 350v from 5800v to 5450v AC, no load to full load. (Center
>tapped secondary, rated 2800-0-2800)
>   So here's my question: I have a drop of 350v AC on the secondary,
>and a drop of around 650v DC at the output under full load. Does this
>all sound OK, or does it sound like I need more filter C?
>   I realize I don't need 900 mA for a pair of 3-500Zs, but this amp
>is going to be used for RTTY contesting, among other things, so I want
>a supply that's up to the task. During all my testing, nothing got hot
>except the resistors.
>Thanks & 73,
>Doug, KF4KL
>
>
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>

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