Re: Lightbulbs and Power Resistors?

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