Gary,
1/2 voltage can be caused by a rectifier, main filter cap, or the voltage
regulator. I'd check the voltage regulator first off to see if I had high
enough DC voltage from the rectifiers going into the collectors of the pass
transistors. If it's low there, it's in the transformer, rectifiers, or filter.
A 20 amp supply generally is only 110 Vac. The biggest thing to fail on these
is the regulator transistors because they handle all the power. Next would be a
bad bridge rectifier. If it's not that, the regulator IC could be bad, the
driver transistors, or the voltage divider resistor network used to set the
output voltage. If you have the proper DC voltage going into the pass
transistors, then it will be in the regulator circuit itself.
Best,
Will
*********** REPLY SEPARATOR ***********
On 5/7/06 at 10:59 PM Gary Schafer wrote:
>I need to know what the primary resistance is of the Astron RS20A
>transformer. I would like to know the resistance of a 220 volt transformer
>and a 120 volt transformer.
>
>Maybe someone has a 220 volt RS20A that could measure the resistance across
>the power plug, that will do it.
>
>
>
>I have a power supply here that is supposed to be a 120 volt unit but it
>looks like it has a 220 volt transformer as I only get around ½ the voltage
>out on 120. This transformer measures around 6 ohms primary resistance.
>
>
>
>Thanks for any help.
>
>
>
>73
>
>Gary K4FMX
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|