Power supply
 

Karl Townsend wrote:
Turns out I have a power supply for my Matsurra bedmill. After
stripping everything not needed away I ended up with this:
http://www.metalworking.com/dropbox/supply1.jpg
http://www.metalworking.com/dropbox/supply2.jpg

A few questions. Each of the twelve diodes has a pair of wires, 24
connections on the terminal strip. I don't know the function here and
if anything needs to be connected.

Is the part labeled 1 an isolation transformer? If so, should DC- be
grounded?

Can the part labeled 2 be used to read current? There are four leads,
how would they be connected. The part says "Nana Electronics NNC-05AF"

Karl


That part is half of a DC drive unit for a DC spindle motor. The parts
that look like diodes are actually SCR's since there are 12 of them it
is a full wave unit vs. a half wave unit using a center tapped Y type
transformer with the center tap being the motor return attach point.
The vfd you are going to dismantle is probably the other half of this
unit. The "transformer" attached to the unit is the reactor to keep
harmonics from getting back into the power line.

The unit could be used to build a nice regulated dc power supply if you
can find the rest of the stuff to go with it. Follow the leads that
went to the 12 thin wires on the terminal strip. Instead of having the
tach feedback from a motor you could use a voltage divider feedback into
the tach input ( you may have to isolate the input) to regulate the
output voltage.

John