Re: Lightbulbs and Power Resistors?

Hi Chris,

I have what Mariss listed as a permanent connection on my power
supply, but I also have a manual switch to drain it fast when I am
testing and setting it up.

a momentary push button switch, and 2 automotive light bulbs in
series. the lights will drain the cap so fast that the bulbs will
not burn out. I put alligator clips on this rig so I can use it on
any machine I am working on.

Another idea passes along is to put a fan in the case that runs on
the power supply. when you power off, the fan drains the caps
quickly.

Since you mentioned you are electronicaly challenged, you might be
interested in looking in the files section for the POWER SUPPLY.pdf
posted by Mariss. needs someone with some electronical competence.

just some ideas.

Dave


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Mariss Freimanis
<mariss92705@y...>" <mariss92705@y...> wrote:

> Chris,
>
> Get a 2.7K 3-Watt resistor and an LED. Connect one end of the
> resistor to the "+" side of your supply. Take the other end to the
> anode of your LED. Take the cathode end of the LED to your power
> supply "-". Your'e set then.
>
> Mariss
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Chris and Dee
> <brunoblazer@y...>" <brunoblazer@y...> wrote:
> > Just after Thanksgiving I fired up my CNC retrofit for the first
> > time. I was quite excited when I ran my first G-code program on

my

> > modified machine and watched the machine mill a ..... square.
> >
> > Now I'm taking some time to:
> >
> > 1.) Build my power supply (original testing was done on a 6a 40v
> > switching supply from work). I'm building a 63 v 22 amp p/s with

a

> > 1KVA torroid I bought.
> >
> > 2.) Package the motor drivers, breakout board, and p/s in a nice
> box.
> >
> >
> > So I built my power supply and it outputs 63v. Great! Except

that

> > once its charged, even if I shut down the p/s, I can't hookup
> > anything to the connector I have coming off of the capacitor

unless

> I
> > creatively and safely discharge the capacitor (we all know how

much

> > DC voltage likes to ARC). I also don't have anything but my
> > multimeter to tell me if the capacitor still has a charge. I

tried

> > using a power resistor from Rad shack on the capacitor so that

when

> > the AC power was removed the cap would discharge somewhat

quicker.

> > However, they don't have any that are rated high enough (or I'm

too

> > electronically challenged to know what one to buy or how to hook

it

> > up). I also wanted to hookup 4 lightbulbs (or LEDS, I don't

care)

> to
> > show me when the cap has a charge and for each of my 3 drivers to
> > show when power is going to the driver. The only problem with

this

> > is that I can't find any bulbs rated for that voltage does rad
> shack
> > carry any voltage regulators for that voltage (not to mention

that

> I
> > would prefer not to have to solder voltage regulators to each

bulb).

> >
> > Can anybody tell me what resistor to buy and how to hook it up
> safely
> > (I thought it just went across the leads of the cap, but maybe

this

> > is wrong). Also, any ideas on how to install bulbs or LEDs to

tell

> > me when the cap and drivers have voltage?
> >
> > Thanks!
> >
> > -Chris Bruno
> > http://www.slideruleracing.com