PRES AP3 Floppy Disk Drive

for bbc micro/electron hardware, peripherals & programming issues (NOT emulators!)
User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

PRES AP3 Floppy Disk Drive

Postby richardtoohey » Sun Apr 30, 2017 1:11 am

AP3 and PRES drive. Seemed reasonably/fairly priced ... is the retro market slowing? Discuss.

IMG_6542s.jpg
IMG_6541s.jpg
I think the drive needs an adapter or cable for power - anyone know what is required? (I'll do a bit more R&D just asking on the off-chance one of you has the same sort of drive sitting right next to you!)

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: PRES AP3 Floppy Disk Drive

Postby 1024MAK » Sun Apr 30, 2017 1:53 am

I do have one. The AP3 works fine (now upgraded to a AP34). But the PRES floppy drive does not work. I'll have a look at the PSU for you later... (as it is nowhere near me...)

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

Re: PRES AP3 Floppy Disk Drive

Postby richardtoohey » Sun Apr 30, 2017 2:23 am

Thanks, Mark, this is what the PSU looks like (don't know if a useful photo). Tried an Electron & Plus 3 power connector (just for size, not powered on) and they both seem a little too big to physically insert (didn't push too hard.)

IMG_6543s.jpg
(It's been discussed before but I'm not 100% sure what the outcome was - looks like the poster there *was* able to use the standard Electron connector: viewtopic.php?t=2203 so maybe just need to give it a bit more welly?!)

Urk, drifting OT again ... [-X

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: PRES AP3 Floppy Disk Drive

Postby 1024MAK » Sun Apr 30, 2017 3:11 pm

Well, there's good news :D and bad news... :-({|=

The good news is that I have found my PRES Floppy Disk Drive \:D/

The bad news is that the PSU has become separated from it, and I have no idea where it is :(

But all is not lost :D

First, my disk drive is fitted with a 2.5mm ID 5.5mm OD mini power connector "socket". That's why a Electron PSU plug will not fit (it uses a 2.1mm ID 5.5mm OD mini power connector).

Any PSU that has an AC output of 15V or 16V AC at a current of 1.2A or greater (VA of 18 or greater) will do.
DC power supplies with an output of 17V DC or 18V DC with current ratings of 1A or greater are also suitable.

If the drive is not worked hard, PSUs with voltages up to a maximum of 18.5V AC are also okay, but for every increase in input voltage, more heat will have to be dissipated by the voltage regulators. 18.5V AC is the limit as the voltage on the electrolytic capacitors gets close to their rating.

IMG_4468.JPG
Top view of the regulator PCB

IMG_4467.JPG
Close up of the regulator PCB

IMG_4466.JPG
Close up of the 7805 and 7812 voltage regulators

IMG_4469.JPG
Trackside / bottom view of the regulator PCB

IMG_4465.JPG
Schematic of the regulator board in the drive case

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
fordp
Posts: 866
Joined: Sun Feb 12, 2012 9:08 pm
Location: Kent, England

Re: PRES AP3 Floppy Disk Drive

Postby fordp » Sun Apr 30, 2017 3:35 pm

Lots of modern USB to IDE external enclosures have a suitable brick style PSU with +5 and +12 outputs.
FordP (Simon Ellwood)
Time is an illusion. Lunchtime, doubly so!

User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

Re: PRES AP3 Floppy Disk Drive

Postby richardtoohey » Mon May 01, 2017 3:41 am

Thanks, guys.

Looks like I've been mixing up terminology as well?

The PSU is the box with/on the cable, and then that connects to the regulator board? So my photo of the regulator board NOT the PSU?

User avatar
daveejhitchins
Posts: 3620
Joined: Wed Jun 13, 2012 5:23 pm
Location: Newton Aycliffe, County Durham

Re: PRES AP3 Floppy Disk Drive

Postby daveejhitchins » Mon May 01, 2017 7:12 am

I think I should be able to help here :wink: Not really one of my most taxing designs :lol:
The Power Block is 15V AC @ 18VA, the connector is: Outside diameter 5.5mm inside diameter 2.5mm.

I'll add a photo, for prosperity, later today - just so people can identify it - Although it does have a P.R.E.S. Disc Drive Power Pack label one it!

Hope that helps - Dave H :D

Edit: Here's a photo of the Power Pack:
IMG_1345.jpg
Last edited by daveejhitchins on Mon May 01, 2017 8:33 am, edited 1 time in total.
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ABR, ATI, AP6, MGC, AP5 . . .
For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: PRES AP3 Floppy Disk Drive

Postby 1024MAK » Mon May 01, 2017 8:10 am

richardtoohey wrote:Thanks, guys.

Looks like I've been mixing up terminology as well?

The PSU is the box with/on the cable, and then that connects to the regulator board? So my photo of the regulator board NOT the PSU?

Both! The whole power supply system is split into two parts.
The box that has a mains plug and lead is a transformer. So the best terminology for this is power supply transformer.
The regulator board in the disk drive case takes the low voltage AC from the transformer and converts it to nice smooth and regulated +5V DC and +12V DC supplies. I call it a regulator board, but it is also fine to call it a PSU as well :D

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
daveejhitchins
Posts: 3620
Joined: Wed Jun 13, 2012 5:23 pm
Location: Newton Aycliffe, County Durham

Re: PRES AP3 Floppy Disk Drive

Postby daveejhitchins » Mon May 01, 2017 8:33 am

Photo added ^^^ above ^^^

Dave H :D
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ABR, ATI, AP6, MGC, AP5 . . .
For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

Re: PRES AP3 Floppy Disk Drive

Postby richardtoohey » Sat May 06, 2017 5:08 am

1024MAK wrote:First, my disk drive is fitted with a 2.5mm ID 5.5mm OD mini power connector "socket". That's why a Electron PSU plug will not fit (it uses a 2.1mm ID 5.5mm OD mini power connector).

Any PSU that has an AC output of 15V or 16V AC at a current of 1.2A or greater (VA of 18 or greater) will do.
DC power supplies with an output of 17V DC or 18V DC with current ratings of 1A or greater are also suitable.
Thanks, Mark & Dave.

So something like this?

https://www.jaycar.co.nz/mains-adaptor- ... d/p/MP3059

It comes with different adaptors so that should get the 2.5mm physical connection.

Output is 15V ... but I don't understand if the current is right (1.5A is more than 1.2A so OK?)

Voltage Input: 240VAC @ 50Hz
Voltage Output: 15VAC @ 1.5A Unregulated
Current: 1500mA

And this is unregulated (?), some are switchmode (?), etc.

User avatar
flaxcottage
Posts: 2735
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire

Re: PRES AP3 Floppy Disk Drive

Postby flaxcottage » Sat May 06, 2017 5:59 am

That would do OK but it seems very expensive for what it is.

Haven't you a spare laptop PSU kicking around? I used one myself rated at 19V 4.2A. The 7805 and 7812 can accept an input up to 35V. Since the laptop PSU output is DC, the voltage on the circuit after the bridge rectifier is less than 19V, whereas with a 15V AC input it would be around 21V. Your disk drive PSU should run cooler. :D

Laptop PSUs on eBay are cheap too.
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer

User avatar
1024MAK
Posts: 6676
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: PRES AP3 Floppy Disk Drive

Postby 1024MAK » Sat May 06, 2017 9:51 am

richardtoohey wrote:So something like this?

https://www.jaycar.co.nz/mains-adaptor- ... d/p/MP3059

It comes with different adaptors so that should get the 2.5mm physical connection.

Output is 15V ... but I don't understand if the current is right (1.5A is more than 1.2A so OK?)

Voltage Input: 240VAC @ 50Hz
Voltage Output: 15VAC @ 1.5A Unregulated
Current: 1500mA

And this is unregulated (?), some are switchmode (?), etc.

Yes, interesting description. There are no consumer PSUs / mains adaptors that output a regulated AC output, as there is no demand for them (and the transformers required are large, noisy, run hot and are rather expensive). So any PSU like this is just a normal transformer, and as such is unregulated. Normally the term "unregulated" is not used as it is redundant.

Yes, that PSU / mains adaptor is suitable. As John (flaxcottage) says, it does look expensive though.

flaxcottage wrote:Haven't you a spare laptop PSU kicking around? I used one myself rated at 19V 4.2A. The 7805 and 7812 can accept an input up to 35V. Since the laptop PSU output is DC, the voltage on the circuit after the bridge rectifier is less than 19V, whereas with a 15V AC input it would be around 21V. Your disk drive PSU should run cooler. :D

Laptop PSUs on eBay are cheap too.
John is correct in that a 19V laptop supply will work. Laptop PSUs are regulated PSUs. One thing that I should make clear, there is a difference between an unregulated DC PSU and a regulated DC PSU. You can use any regulated DC PSU with a output voltage between 17V and 22V. Polarity of the DC supply does not matter in this case, as the internal bridge rectifier diodes on the regulator PCB in the disk drive case sorts out the polarity automatically.

Although the 7805 and 7812 have a input voltage range upto 35V, the limiting factor is the voltage rating of the electrolytic capacitors. In this case, the two input smoothing capacitors are rated at 25V maximum. So leaving a head room of 3V, gives 22V.

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
richardtoohey
Posts: 3354
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand

Re: PRES AP3 Floppy Disk Drive

Postby richardtoohey » Sun May 07, 2017 1:23 am

Thanks all ... think I've got a multi-connector adaptor like this already ... somewhere :shock: :-k ... and definitely got lots of laptop power cables around the place ... Vendor wasn't sure if the drive even worked so worth seeing if I can scavenge something up power-wise before spending any more $$$s.


Return to “hardware”

Who is online

Users browsing this forum: Google [Bot], trixster and 8 guests