Ignoramus20905 wrote:

On Sun, 26 Feb 2006 12:14:30 -0600, Don Foreman wrote:
On Sun, 26 Feb 2006 01:11:04 GMT, Ignoramus2596
wrote:

I have a few power supplies PP-1104C that are rated 100 A at 14 VDC
and 50 A at 24 VDC. Not quite sure yet, but I think that they are CC
power supplies. I would like to know if I could rig up one or even two
in parallel or in series (100A at 28V) with a mig gun like Ready
Welder and weld with that.

Some pictures of them are at

http://web.govliquidation.com/auctio...ctionId=767646

I figure that 200A at 14 VDC can weld just about anything.

Any thoughts?

i
You're probably going to want 22 to 28 volts.

Thanks. If their DC output is isolated from ground, then, I hope, I
can put them in series instead and switch them to 100A, 14V
outputs. In series of two, that would give me 100A, 28 volts. As they
seem to be able to go beyond

100 amps is enough for thin metal, maybe up to 1/8" with fluxcore.
However, if they have foldback current limiting they'll trip out
when the wire touches the work.

That would be unfortunate.

The manual for them is he

http://www.tpub.com/content/elecequi...1-6130-246-35/

The schematic (that I printed out and have in front of me) is he

http://www.tpub.com/content/elecequi...0-246-35_8.htm

Here's what it says about regulation at

http://www.tpub.com/content/elecequi...0-246-35_9.htm

``The difference between the power supply output voltage and the
reference voltage con- trols the degree of saturation of magnetic
amplifier T2 to provide regulation of the power supp]y dc output
voltage. Any deviation of the power supply output voltage results in a
variation of the control current applied to the saturation control
winding of magnetic ampli- fier T2. This action controls the degree of
saturation of the magnetic amplifier core and changes the impedance of
the saturable reactor windings. This impedance change is presented to
the transformer T1 secondary winding volt- ages to control the voltage
applied to rectifiers CR1 and CR2 and to return the power supply
output voltage to the correct value.''

also:

``The reference circuit maintains a constant voltage to
the load as the load conditions vary. The reference circuit
consists of reactor L4, transformer T3, bridge rectifier CR3,
variable resistor R4, filter choke L3, and magnetic amplifier
T2. The input ac voltage is applied to transformer T3. During
each half-cycle of the ac voltage appearing across transformer T3
secon- dary, two diodes in bridge rectifier CR3 conduct in series and
produce a direct current (dc) pulsw in the output. During the
second half-cycle of the ac voltage that appears across
transformer T3 secondary, the two other diodes in bridge
rectifier CR3 conduct in series, and produce another dc
output pulse in the same direction. These dc pulses are then
applied as reference voltage to the saturation control winding
(ter- minals 5 and 6) of magnetic amplifier T2. Variable
resistor R4 adjusts the output of bridge rectifier CR3.''

So, it seems to my uneducated eye that they do not have foldback
current limiting, or really much current limiting at all. There is a
breaker CB1(A,B) though. (on the top left, on the AC power line side)

i

As long as you don't get any oscillation in the mag amp. it should work
fine. The unit has voltage regulation and also you can vary the output
voltage which is necessary to vary the heat of the welding process.

John