Battery charger for supply

Hi, just wanted to clear up a few things.

I did mention that battery chargers could be used as power supply,
and Mark added some remarks about it. What I said was that you
could often find a usable transformer. The most simple ones, just
have a transformer + bridge rectifier + ammeter + current limiter.
You don't have to connect a battery. You use a capacitor instead. (
Tom in NY - gave a good description on the subject )

More advanced chargers, will also work with a large capacitor, but
you will get a regulated voltage and you may also have some
electronic current limiting. Many of these, use very common voltage
/ current regulators. You can replace trim pots, with an axle
type, - and have a variable supply.

If it is a switch mode supply, then it can be a little more tricky.
But they will work too.

On some, you need a small current to flow, and in many cases a light
bulb will work fine. All I intended to point out, - is that they are
easy get hold of, and in many cases, they will do the job.

Some have calculated that : " I have 3 step motors, each draw 5 Amp
- I have to find a power supply that will output 15 Amp "
This is not that simple, but let say it is - you can just as well
use a separate power supply for each motor. You even may have an
added bonus: less interference.

I am not favoring this or that, just saying that you may find it a
simple solution, - and in my case I have had some old chargers
given to me for free. Can't get it much cheaper.


To Ray Henry:

I have not tested Tim's script, so I don't know how that works, -
but I guess you only have to list out the lilo.conf to see if the
dos/Win is still there.
And, no - the EMC sim don't use RT modules. To see any modules - use
the command <lsmod> .

Terminator:

Well, you will not be able to see much with a led, - and I guess -
not much fun. I do understand that you would like to have something
to run, so I just pass on this idea, and see if anyone in the group
would have something to say about it.

I guess most of you already have some stuff stored away, - and I bet
some have some old floppy drives. This has all you need. A step
motor driver electronics.

Pin 10 = input Motor Enable floppy no. 1
Pin 12 = input Select floppy no. 2
Pin 14 = input Select floppy no. 1
Pin 16 = input Motor Enable floppy no.2

On an old 5 1/4 floppy drive, they either have a twist on the cable,
so you select either floppy 1 or 2 ( drive A or B ) - but there may
be jumpers on the
floppy drive as well, so you can select which one it should be. The
Motor Enable signal will spin it up, - you could "pretend" you
started a pump or spindle on a real machine.

The select signal, could be wired to a motor enable signal from the
EMC, - and the led on the floppy should turn on.

Then,

Pin 18 - input Direction
Pin 20 - input Step pulse

Here you can run the head in or out.

Pin 26 - output Track 0

This can be used as an end switch input, or a "home" input

All odd numbered pins is ground.

--------------------------------

All you need is some wire ! You have power/motor/ switches/led/
etc.

I have not checked the EMC step motor interface or the Machine
control IO, but maybe there could be some use for the index pulse
output on pin 8, if you have a floppy inserted. This could count
revs, or what ever. If you added some parts from another floppy, -
you could mount the optical sensors, cut some holes in the floppy,
and make encoder pulses. But if used as it is, - it could be a nice
little testing device. There should be a little G code program to
run.

Add floppy drives, and you could run run x, y, z axis. You could
even make a miniature machine out of it.

So maybe there should be made a little cable - to interface a floppy
drive as a test device ?


//ARNE