Commodore 64 Floppy Drive Transformer

[CivicProtection]

In the process off looking for a big beefy transformer for my mag-amp project, I pulled out of my closet this big old floppy drive I had bought about 4 years ago. I'd never owned a Commodore 64 but the drive was at a thrift store for $5 and I thought it might be useful, and it had a nifty look to it.

This morning I pulled it out and took the cover off. I looked at the transformer and it looked really robust. So I powered the drive up and tested the four lines running out of the secondary to the motherboard.
I didn't write it down and I'd forgotten it, but I tested two hot lines and it read around 14-16 volts, and trying one of the hot lines with a neutral I got either 4-8 volts respectivly.

It was a big hairy piece of iron, and I was wondering if anybody else takes these olf diskdrives and uses the transformer for tube stuff or anything else.
I extracted the transformer and it came out in a nice bundle, no desoldering was needed. I got a nice clicky high power rocker switch, a fuse in a screw holder, and a nice computer power cord type socket. No reconstruction of the circuit is needed its all in one piece.

Never mind that it might be worth money now, no. I just tore it all apart and plucked the sucker right out.

It looks like it will handle atleast an amp of power. There is a red wire jutting out of the transformer with the end shrink tubed closed. I wonder what it could have been? It wasn't connected to anything.......interesting.

[CivicProtection]

Took some pictures after making the thread:

Size comparison with coffee cup:
Imageshack - im000012.jpg

Close up of transformer and writing:
Imageshack - im000013.jpg

A look at the secondary wiring:
Imageshack - im000014x.jpg
I am begining to suspect that red wire might be for another hot incoming line.
Maybe the transformer could be adapted for 220v with the use of the red wire, but in my model being run on 110v it is simply not used and covered with srink tubing. Ideas?

[CivicProtection]

I unscrewed the fuse from the little holder, and it is indeed a 250V 1A fude.
Is this a 110/220v transformer?
I looked closely at it and pinched the rubber shrink tube covering the end of the unused red wire, and it has a terminal connector attached to it in there. I think that is what is in there.

What the hell is that red wire for!?

[Pano]

That's a lot of transformer for a floppy drive! Was it the giant 8" floppy?
Hard to tell, but you may have a dual voltage primary. It's pretty common. You could find out with an ohmmeter.

FWIW, my 1st home computer was a Commadore PET. So found memories for me. Before the C-64 (circa 1978) and it used cassette drive, not floppy.

[CivicProtection]

Originally Posted by panomaniac

That's a lot of transformer for a floppy drive! Was it the giant 8" floppy?
Hard to tell, but you may have a dual voltage primary. It's pretty common. You could find out with an ohmmeter.

FWIW, my 1st home computer was a Commadore PET. So found memories for me. Before the C-64 (circa 1978) and it used cassette drive, not floppy.

I know right!? It was taken from a "Commodore 1541" 5 1/2 drive.
Here is a picture I found: http://nielsthooft.com/images/12.jpg

[CivicProtection]

Originally Posted by panomaniac

That's a lot of transformer for a floppy drive! Was it the giant 8" floppy?
Hard to tell, but you may have a dual voltage primary. It's pretty common. You could find out with an ohmmeter.

FWIW, my 1st home computer was a Commadore PET. So found memories for me. Before the C-64 (circa 1978) and it used cassette drive, not floppy.

I have a multi meter, I didn't get much of a reaction when I tried the red lead, I don't think my probe was making contact. Hmmm.
I tried looking up the specs on the tranny, no dice!

[Pano]

1st thing to do is measure the DC resistance of the primary winding at it's set up now.
Then measure the DC resistance of the red wire to both of the current primary wires. If there is no continuity, then it's not part of the primary winding.

If there is, you may be able to figure out how it fits in.
BTW, why do you care? Are you trying to run this on 220V, or do you have some other use in mind?

[CivicProtection]

Originally Posted by panomaniac

1st thing to do is measure the DC resistance of the primary winding at it's set up now.
Then measure the DC resistance of the red wire to both of the current primary wires. If there is no continuity, then it's not part of the primary winding.

I'll try that.

[CivicProtection]

Originally Posted by panomaniac

BTW, why do you care? Are you trying to run this on 220V, or do you have some other use in mind?

No I won't be running it on 220v. I was just curious thats all.
They decided to use the same model transformer for both Europe and US/Canada. For 220v regions; I assume all they needed to do was use the red wire and then tape off the neutral wire. And still use the existing input socket and fuse.

Also the other reason I was trying to figure the red wire out is because I was hella bored this morning.

[Pano]

That's a legit reason. +)