I switched to capacitor input and changed the load to 5300 ohms. Now I am getting 438V and
83 MA. I stuck a fuse on the transformer just in case and I will let it run for a while.
It is noticeably warm but not uncomfortable to touch. If it can operate at this level it
will be fine for my project.
On 9/1/2012 1:37 PM, Vic K2VCO wrote:
Some of you will remember that I was wondering about utilizing a small Philco power
transformer (model 45-7011-7) for a screen supply. It puts out 380-0-380 vac plus 5 and
6 v for filaments. I have hooked it up jn a full-wave ct circuit feeding a choke-input
filter and 20 uf capacitor. It is feeding a 4300 ohm 50w resistor for a load.
I measure an AC voltage of 378v on either half of the secondary and 315v DC across the
load (83% of the AC). Current is about 73 ma. It has been sitting for about 20 minutes
and I can detect a very slight rise in temperature of the transformer. I am going to let
it sit for at least an hour.
I think that I am proving that I will be able to draw this much current, but the voltage
is too low. Next I am going to try it as capacitor-input and see what happens.
--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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