Re: Lightbulbs and Power Resistors?

Hi Bob,

I wouldn't want the load on my PS when running.
A 110VAC relay on the mains, and the light on the DC bus. power on
and the relay energizes, power off and the light gets in the
circuit. You could use almost any light, probably even an auto light
as the high ohm load will bring the time constant down to 2 or 3
which means the bulb will never get hot. They make Pilot lights and
Radio Shack has some cheap ones that take screw in bulbs. you can
get screw in bulbs for 110VAC that are the same size as flashlight
bulbs to fit.

Heck, you should be able to get most any voltage, pilot lights from
old equipment still use filament bulbs. Your old soldering iron had
a 110 screw in bulb.

Dave





--- In CAD_CAM_EDM_DRO@yahoogroups.com, "echnidna <echnidna@y...>"
<echnidna@y...> wrote:

> You could be a little bit unorthodox and just fit a simple

household 110 volt globe across the cap. At 63 volts it will
illuminate in the yellow range instead of white light but will be
quite visible. By altering the wattage of the globe you can alter the
cap discharge time. More watts means faster discharge.

>
> Regards
> Bob Thomas
>
> --- 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