Power supply option?

[taximan]

I was going to throw this digibox away and decided the case might come in useful fom my mbfm project as well as being a subject for soldering/desoldering practice.

This is a shot of the power board

These are the leads out from the power board

This is the information on the board itself

I tested it with the meter and the 12v is shoving out 16.3 volts (can I choke it somehow?)

The 5v out is showing 4.87 volts which I suspect may be enough.

Long post shortened…is this power board useable for the mbfm box?

Cheers

Paul O

[lylehaze]

I was going to throw this digibox away and decided the case might come in useful fom my mbfm project as well as being a subject for soldering/desoldering practice.

This is a shot of the power board

These are the leads out from the power board

This is the information on the board itself

I tested it with the meter and the 12v is shoving out 16.3 volts (can I choke it somehow?)

The 5v out is showing 4.87 volts which I suspect may be enough.

Long post shortened…is this power board useable for the mbfm box?

Cheers

Paul O

That appears to be a switching supply (I can’t be sure)

I have two concerns..

A switching supply can add noise to an analog signal.

Switching supplies often require a minimum load to regulate properly.

If you were building an all-digital project like a MB64(e), the first concern would not apply.

Your comment about the 12 volt output seems to confirm my second concern above.

Good Luck,

LyleHaze

[taximan]

That appears to be a switching supply (I can’t be sure)

I have two concerns..

A switching supply can add noise to an analog signal.

Switching supplies often require a minimum load to regulate properly.

If you were building an all-digital project like a MB64(e), the first concern would not apply.

Your comment about the 12 volt output seems to confirm my second concern above.

Good Luck,

LyleHaze

Based on your reply I am going to look elsewhere and not use it.

Many thanks for your input

Paul

[seppoman]

I have two concerns..

I’ve got a third one - it doesn’t have a -12V output

S

[nILS]

I’ve got a third one - it doesn’t have a -12V output

That’s less of a concern than a knockout-criteria :yes:

[taximan]

Guys,

Thanks for trying to put me straight with this but rest assured I have come down on the side of safety and put the power board in my part box…probably never to be seen again..lol.

Okay now for the serious stuff,I am a noob (as I guess you guessed) and have been trawling forum posts and documentation from ucapps,trying to figure it all out myself (which I think is the best way to learn by the way.

The thing is this,I am building a minimal mbfm as a way of getting my feet wet as I have a sammich on order and I am also on the seqv4 waiting list (wilbas kit).

I cannot get my head around the power supply needed for the mbfm (the +/- 12v)

If anyone could tell me what exactly I am looking for I can get my nose back into my maplins catalogue and see if they have anything.

To summarise this post,bad bits gone in bad bits box,I need a dummies explanation of what 12v transformer I need. (I followed a link to pollins but I can only order beer and kebabs in german so that was a non starter).

All help really appreciated.

Paul

[frailn]

If anyone could tell me what exactly I am looking for I can get my nose back into my maplins catalogue and see if they have anything.

Try an <___base_url___>/index.php?/topic/13368-amiga-psu/&do=embed I just checked eBay UK and there are several for sale. Just make sure you get the correct type. There were two types produced by Commodore. The correct type is very heavy, because it is a linear PSU. The wrong type is very light, because it is a switching supply. You don’t want the switching supply.

The one I plan on using:

Type: A500 type 1

Part number: 312503-02

Current: 5V/2.5A * 12V/1.0A * -12V/0.1A

Total power: 25.7W

There are at least two of these for sale on eBay UK with buy it now option. The only thing you will have to do is modify the PSU by removing the connector that plugs into the Amiga and replace it with a more standard connector. The connector is not standard and you will be hard pressed to find a receptacle to match it, unless you choose to cannibalize one from an old Amiga (which I would not recommend - save the Amigas!)

This option will not fit in your case, but would be an external solution.

[taximan]

Thanks for the detailed info frailn,I have ordered the psu from the link (weight 2.4kg!!!) the postage was nearly as much as the psu.

I will be buying the 4 pin connector you mention as well.

So my mbfm parts list now looks like this …

Many many thanks

Paul

[frailn]

Thanks for the detailed info frailn,I have ordered the psu from the link (weight 2.4kg!!!) the postage was nearly as much as the psu.

I will be buying the 4 pin connector you mention as well.

So my mbfm parts list now looks like this …

Many many thanks

Paul

Glad to be of help! Let me know how that 4 pin connector works out.