RE: [CAD_CAM_EDM_DRO] Toroid Transformer update

Chris,

There was a lot posted about a month ago on how to connect a center tap
transformer to get in your case 44V at 9 amps. It it just takes 2 diodes
or using a bridge in a couple different configurations depending upon
what you want.

Tim
[Denver CO]
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> -----Original Message-----
>
> Well, Thanks to you guys in the group, I was able to run one of my
> Toroids loaded on the bench for about two hours today. I
> conclude that
> it is rated for 44v 4.5amps.I fused the transformer with a 10
> amp fuse.
> The first load I connected, A calrod, was about 4 amps
> according to my
> clamp-on Amp meter. After about a half hour, I could not
> detect any heat
> by hand in the transformer, but I noticed the Amp load
> dropped now that
> the Calrod was hot, to just over two amps. So, I added
> another 1500 watt
> heater in parallel. This jumped the amp load to just under 9 amps.
> Nothing started to smoke, so I left it run. After about 15
> minutes, the
> amp meter showed 4.9amps. The Transformer was showing 85
> degrees. After
> an hour of this running, the temp was just a tweak over 80
> degrees which
> I assume dropped because the load was lessened as things
> warmed up. At
> this point, I recall the AC load on the primary was just over 2 amps.
>
> So, Cool ! looks like I found my transformers. I doubt I need
> more than
> 3.5 amp per axis.
>
> Now, Bob Thomas indicated that I could "parallel" these three
> transformers ?? Or should I just use one per axis ?? If I did
> parallel
> them, I assume I could take one half of each transformers
> secondary, and
> simply parallel them. Not sure. I see fuses blowing already !!
>
> If you remember, these were "dual" secondarys. I guess each
> leg could
> put out 4.5 amps 44v, but I threw a 2 amp fuse between the
> two hot legs
> and it popped. Obviously I can not combine the "dual"
> secondarys on one
> transformer to get 9 amps, but I could run two drives off of one
> transformer....
>
> I will do some full day testing yet and get it all written
> down, But, I
> sure was thrilled to find out they were capable of at least
> 4 amps per
> leg !
>
> Thanks to all,
>
> Chris L
>
>
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