Re: Power Supply and Capacitor Questions Help!!

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "rogersmach"

Wire the capacitors in parallel, you only need 1 resistor if you feel
you need a bleed. Check the wire size of the transformer
secondaries, if they are similar, wire the 31 V in series with the 10
V, check with a voltmeter you should get 41 VAC, if its 21V swap one
pair of windings. Use one bridge rectifier across the 41VAC, when
connected with the capacitors you will get (41 x 1.414) - approx 1.5
(bridge diode drop) VDC, near enough 55 VDC, you can increase it to
slightly over 60VDC by also including the 4 volt tap, again if it is
of similar gage ( or bigger) than the other two. The 320s are
conservatively rated at 80VDC.

Bernard

> Hello,
>

I'm using a

> power supply from the old control of my bridgeport which has 4 set

of

> output taps on the secondary and their voltage values are: 1 set at
> 31 volts AC, 1 set at 10 volts AC, 1 set at 4 volts AC and the

other

> set read 0. In talking with Mariss at Gecko drive (brilliant man,
> hate to bother him), he suggested that I use about 60 volts DC with
> his drives. Which would reduce the speed with little effect on the
> torque (if I understood him correctly). And I would need a 100 volt
> DC capacitor rated at 45,000 macrofarad or greater. I could not
> locate a cap with this value and had to settle for 3 100 volt
> computer grade DC caps at 15,000 macrofarad. Question: Can I wire
> these 3 capacitors in series to achieve the same Macrofarad value?

I

> intend on using a 1.2k 5 watt bleed resistor on each. Next

Question:

> Would it be possible for me to run the 31 volt taps through one
> bridge rectifier and 10 volts through another bridge rectifier,

wire

> them in parallel to get my output up to around 41 volts DC? Is it
> possible to change the configuration of the primary side and get
> higher values? I intend to use the present supply temporarliy to

get

> operational, then acquire a more adequate supply later. At the 31
> volts it appears to be pushing the X axis (servo running directly

off

> of bridge at 31 volts DC without capacitor and a 2.5:1 reduction)
> about 30 inches/min Id like to get it around 70 or 80 inches /min
> rapid. Any more than that is unsafe on a bridgeport. Any input on

my

> inquiries would be appreciated.