[ARC5] Radio Shack transformers - was:Vibrator Power Supplies

[J. Forster]

I just measured the core loss of a Radio Shack 12.6V @ 2A transformer. The
unit is low loss to about 115 VAC, then rises rapidly:

VAC      Power

090       2
100       2
110       3
120       4
130       6
138       8

The instrument was a Sencore PR570 which analog multiplies V & I, so it's
real power, not reactive. This is virtually all core loss. Since the
transformer is unloaded, the copper losses are small.

-John

===========================




> Hi,
>
> I have a 12 volt CT model and 2 24 volt CT RS transformers. The 24 Volt
> unit is on my bench right now to power the heaters in an ARC-5 receiver
> (BC-453). It's only being called on for about 450 mA but does not even
> get warm to the touch after running for several hours. I have another 24
> volt unit here. I'll check them out with a heavier load, too. I'll check
> the temps and look at the waveforms. Might get to that over the weekend.
> I am using and planning to use more old iron and I want to *know*, too.
> In fact I can double the load by running the heaters in my BC-454 at the
> same time. They are sitting side by side.
>
> Line voltage here has been around 125 volts when I have looked.
>
> 73,
>
> Bill  KU8H
>
>