Floppy drive AC adapter

[Junya]

Hi. I am Junya and I come from Japan. Hello everyone. Sorry my English is not good.

My question: I want to make a power adapter to feed power to floppy disk drive. From my understanding (according to website) I can use the floppy with DC+5V ±10%.

http://www.teac.co.jp/dspd/product/magnetic/fd-235.html

I have AC adapter that output 5+ DC, but no idea how I can run it. It comes from old celluar phone. I know I need cutting the cables and connect them to wire, but how I can connect the ground (middle two of the four pins on floppy). How I can do this?

Also, is important that I connect certain cable to certain pin? The AC adapter has two cable inside and if connect them to floppy with a 4-pin adapter then which cable goes to data and which goes to power? Also how I can know which one I should put where?

Sorry my confusing question. Thanks all

[Thorondor]

Older (and even some newer) computer power supplies may still have floppy drive power connectors. For a stand-alone power supply you can buy a floppy power adapter and use its connector.

Floppy drive power connectors have 12VDC (yellow wire) and 5VDC (red wire).

[Gyro]

Junya, your written English is excellent. 

[electr_peter]

I have AC adapter that output 5+ DC, but no idea how I can run it. It comes from old celluar phone. I know I need cutting the cables and connect them to wire, but how I can connect the ground (middle two of the four pins on floppy). How I can do this?

I assume you have some AC-DC adapter that plugs in mains AC outlet and provides 5V DC to charge the phone. You could modify it to work with the floppy, however, this charger may not have enough current capacity for floppy drive. Do you see any specs on the charger?

Also, is important that I connect certain cable to certain pin? The AC adapter has two cable inside and if connect them to floppy with a 4-pin adapter then which cable goes to data and which goes to power? Also how I can know which one I should put where?

4 pins are [12V DC, Ground, Ground, 5V DC]. Two inside pins are connected to each other. If your floppy could work on 5V DC supply, you would put positive wire from the AC-DC adapter to 5V line and negative wire to Ground.

Floppy specs mentions ~1.4W operating power, which is 280 mA under 5V. If you AC-DC charger is capable of 500 mA or more, floppy disk drive should work.

[Junya]

Hello thank all for every replies. Yes. I think using older PC supply might be a solution but it would be not very cost effective to use it just for a floppy drive hehe.

This is information for adapter:

INPUT: AC 100V  50/60Hz, 30VA

OUTPUT: +5V, 2.5A

I think I can understanding it now. Only question is how I can know which is positive vs negative wire?

Thanks 

[electr_peter]

Only question is how I can know which is positive vs negative wire?

Do you have a DMM (digital multimeter)? If not, then get one and you could test voltage level, polarity, current, resistance with it - very useful item.

Red wire usually means positive voltage and black wire usually means negative voltage or ground. You could also test polarity with some LEDs connected in series.

[Richard Crowley]

You can identify the positive output from the power supply with a simple meter.
If you are going to be doing any work with electricity or electronics, you should at least have a meter.
Even a very basic and inexpensive (US$5 or 600 Yen) meter would be very useful.

You need a special connector for the power.  Millions of these connectors and power cables were discarded along with the obsolete drives.
If you search a junk pile or a computer recycling place, you can probably find a floppy drive power cable/connector.

Once you have the +5V and GROUND wires identified, you can connect the +5V to pin 1 and the ground to pin 2.
Pins 2 and 3 are connected together. You do not need to connect to both 2 and 3.

The connector at the top is for a larger 8-inch floppy drive.
The connector at the bottom is for the 3.5 inch floppy drive