Anyone with a psu for Microperipherals Floppy Interface?

[cercamon]

Hi all.

Old thread, but instead of opening a new one, I try to write here.
I have recently acquired the Micro Peripherals interface and a single floppy disk drive. In details:

Micro Peripherals FDD interface SPC-BBT
QLFDC v5.1 (ROM v5.3 Italian) - DD50 S/N: 5501600

I don't have the PSU to be connected to DIN6 plug so I'm looking for the original one or a good replacement.
Also looking for the QJump ROM to switch from FDK_ to FLP_ device names.

TIA
Cercamon

Adding some pictures may help.

[cercamon]

Seems like a replacement PSU should convey 15V and 9V to some pins of the DIN6 plug, according to this picture I've found:



Will keep on looking...

[1024MAK]

I'm sure this subject has come up elsewhere (maybe on World of Spectrum, on StarDot or another retro forum).

Anyway, we need to see inside the case. As there should be the real DC power supply inside. The external power supply is just a mains transformer in a neat plastic case.

The DC PSU can run from either suitable AC inputs, or from suitable DC inputs. The problem is, however, neither type is very common

It is possible to still get custom wound transformers, but I suspect they will be expensive. And you still need a suitable case, plus the need to wire everything up in compliance with electrical and safety regulations.

The easier route is to buy a 12V DC regulated power supply that can supply at least 2A. Then if you can solder, use a "simple" 5V SMPSU chip and four capacitors to generate the +5V supply from the +12V rail. You could even fit the 5V SMPSU chip to the PCB of the existing DC PSU.

Mark

[cercamon]

Thank you, Mark.

I'm almost useless with a soldering iron in my hands, still I guess I'm going to open up the drive box and see the actual type of plug to the disk drive.
But it would be too difficult for me to build up an AC adaptor, even starting from a standard 12V PSU as you suggest. If I happen to make any progresses, I'll update this thread.

[cercamon]

Just a shot in the dark, but what if I buy one of these modern PSUs and replace the DIN6 plug at the end?

http://www.ebay.ch/itm/Cargador-Corrien ... Sw5dNWkjgQ

Voltages of +12V and +5V (2A) are provided, so given the right pinout of the disk drive's input plug, this should work, shouldn't it?

[Bloodnok]

Hi,

I have used these type of PSU for floppies and they work fine. They are plentiful on ebay, and other markets, and quite a bit cheaper as well (http://www.ebay.co.uk/sch/i.html?_from= ... SK&_sop=15). I've had problems with some of the IEC power cords being of low quality but otherwise OK.

I've checked my MIcro-peripheral's connections inside and it's very straight forward. Just two standard linear supplies for +12V and +5V:

PSU

The connector to the floppy seems to be standard as well (unlike the Amstrad 3" drives!) :

Floppy drive - PSU connection circled

The left hand DIN connector on the case (from the rear) has +12V and +5V from the internal PSU and connects directly to the floppy so could use that to provide power from the external DC supply with the appropriate DIN connector.


So just the usual caution of checking and double checking all connections before powering up and all should be fine. If you've got another 720K 3.5" floppy drive that you know is good then best to try that out first.

Charles

[1024MAK]

Warning
There is a reason that these "Power-Supply-12V-5V-AC-Adapter-For-Hard-Disk-Drive-HDD-CD-DVD-ROM" (and other similar descriptions) power supplies / power adaptors / mains adaptors / power bricks are very cheap. They are rubbish. Why do I say that? Well, for a rather large list of reasons. To keep the price low they:

1. Don't bother with any components to provide filtering on the mains side, so they will leak all kinds of electrical noise into your electrical wiring / system;
2. Most don't comply with our regulations on having sufficient clearance and creapage distances between the PCB tracks at mains voltage and the low voltage output circuitry, some PSUs have been found to have track spacings of 0.5mm. A properly designed and engineered power supply would have a spacing of 5mm or more;
3. The type and construction of the high frequency transformer normally does not have sufficient isolation between the primary (connected to the mains input) and the secondary (which provides the output);
4. They use the cheapest components possible, some of which may not perform very well and may not last very long;
5. They use a very basic, poorly performing circuit design;
6. As a result of the above, they run hot, have a poor efficiency, have very poor regulation of the output(s) and the output is electrically very noisy, and may not actually supply the "rated" current;
7. The poor regulation of the output(s) and the noise on the outputs can cause malfunction of the electronics of the device you are using it to power;
8. As they run hot, some may be a fire risk, as I doubt the plastic used in the cheap, thin walled case has any fire rating.

So even if you are okay with all of the above, keep in mind that your excellent value power supply may die much sooner than you would like. They are not designed to last...

When buying a power supply, I strongly recommend you buy from a shop or supplier in your own country, from a shop or supplier that has a good reputation. So that in the event of problems, you can get a refund. They are also more likely to only sell power supplies that meet the safety requirements in your country.

Mark

[1024MAK]

As Bloodnok says, inside the outer case, the actual FDD is using a normal DC FDD type power connector. So it's standard +5V and+12V DC supplies.

If you have a unused older type working ATX power supply (the type that has a main 5V output, NOT a main 3.3V output, the main output is normally the one with the highest current rating), you can use this to power your floppy drive.

Mark

[1024MAK]

I have used these type of PSU for floppies and they work fine. They are plentiful on ebay, and other markets, and quite a bit cheaper as well (http://www.ebay.co.uk/sch/i.html?_from= ... SK&_sop=15).

Please read my warning a couple of posts up.

The left hand DIN connector on the case (from the rear) has +12V and +5V from the internal PSU and connects directly to the floppy so could use that to provide power from the external DC supply with the appropriate DIN connector.

I recommend that the wiring between the internal (power supply) regulator board and the output DIN connector / internal FDD power connector be disconnected. As it is unlikely that the regulator board has protection for powering "in reverse". Some regulator chips don't like having their outputs powered with no input voltage. The reverse current flow may cause the device to break down causing excessive current consumption and heat.

@Charles - thank you for posting up the pictures

Mark

[1024MAK]

Just a shot in the dark, but what if I buy one of these modern PSUs and replace the DIN6 plug at the end?

http://www.ebay.ch/itm/Cargador-Corrien ... Sw5dNWkjgQ

Voltages of +12V and +5V (2A) are provided, so given the right pinout of the disk drive's input plug, this should work, shouldn't it?

At first glance, this PSU looks okay. But when looking at the pictures, I am concerned that there are two different pictures both showing the pin-out of the mini DIN output plug. Which is the correct picture for the item that the seller is actually selling?. So something is wrong here. There is a supplier in the UK with the URL of http://www.power-adapters.co.uk I do not know enough about this company, so don't know if it sells overseas.

And to answer your second question, yes you could cut-off the existing mini DIN plug and solder the wires to a DIN plug suitable for your disk drive.

Mark