Re: [CAD_CAM_EDM_DRO] Stepper Power Supply. Question about Voltage

Hi Tom,

Sounds like two diode drops. AND, without the cap, you won't see (the
cap) charging to the P-P voltage. Add the cap, your voltage should come
up to about 37V. You should do fine.

Alan KM6VV


kaynrc wrote:

>
> Hello
>
> I am just getting around to selecting some transformers to build
> sparate little power supplies for Dan Mauch's 5 amp boards, and each
> transformer is rated at 26 VAC, 5 amps. I plugged one in, and read it
> at 29.2 VAC, which is fine by me.
>
> Then I connected the bridge rectifier and got a surprise, which is a
> reading of 26 VDC. I had not yet hooked up the 10,000uf, 50 VDC
> capacitor. Because the VAC is supposed to be higher than the VAC (by
> a factor of 1.41) I expected the DC voltage to be higher, around 35
> to 39 VDC. Again, it might be important that I did not attach the big
> cap yet.
>
> So, what's going on? Will I notice a voltage increase when I add the
> capacitor? Why is my DC voltage so low just taken right off the
> rectifier, since it's only suppose to consume around 1.7V? Is the
> transformer perhaps too small to supply proper voltage? And last,
> these 521 oz-in motors that I got from Camtronics (and the circuit
> boards) can run up to 40VDC, so am I simply going to operating slower
> with somewhere around 25 to 30 VDC? Noticably slower?
>
> Thanks, Tom.