[Amps] Bridging 120v loads across HV primary windings

[Vic K2VCO]

On 5/31/2010 4:32 PM, Bill, W6WRT wrote:
> ORIGINAL MESSAGE:
>> Another option is bridging the 120V loads across the two halves of the 240V plate
>> transformer's primary. I've seen this done with fans, etc. The primary acts as an
>> autotransformer to provide half voltage. Then I could use a simple 3-wire hookup.

> The second option is more problematical. The transformer will function
> as an autotransformer like you suggest, but the question is how good
> the regulation would be as the loads are varied. You will have two
> loads which vary: The screen supply on the primary side, and the plate
> load on the secondary side. Both will affect the other and both will
> be affected by resistance of the transformer windings and the
> tightness of coupling between the primary and secondary. If the
> regulation is not good, that will have a bad effect on your heater
> voltage as well.

I've decided to use a 4-wire circuit, including a neutral for the 120v loads. The 
connectors are expensive and most of the local hardware stores didn't have the 4-conductor 
cable for the line cord, but these difficulties have been surmounted.

I have lots of areas for experimentation in my project, so I think I'll do this part 
conventionally.
-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/