Author Topic: Odd power supply request  (Read 3591 times)

tiges_ tendres

Odd power supply request
« on: January 05, 2015, 05:11:19 PM »
Hello,

I am trying to figure out the best way to make a power supply to provide me with the following:

5v at 2A
10v at 1A

What I'd like to do is use a standard wall-wart to get the voltage, and then somehow drop it to get those voltages/amperages as above.

What this is actually for is a Neo Geo CD, video game system.  The standard power supply is hard to come by and has a proprietary connector, making it difficult to get affordable replacements. 

Thanks!
Try a little tenderness.

R.G.

Re: Odd power supply request
« Reply #1 on: January 05, 2015, 07:47:08 PM »
I would find a 10V/3A or 12V3A power supply, then make the 10V/1A out of 12V (if that's what you started with) and the 5V/2A from the original supply.
R.G.

Quick IQ Test: If anyone in a governmental position suspected that YOU had top-secret information on YOUR computer, how many minutes would you remain outside a jail cell?

ACS

Re: Odd power supply request
« Reply #2 on: January 05, 2015, 07:58:34 PM »
^^^ LM7810 from "anything" should give you the 10V/1A, LM7805 + http://www.electroschematics.com/1961/lm7805-voltage-regulator/ gives you the 5V/2A.

A cheap laptop power supply could be the answer for your initial source voltage - it's about the only easily accessible item I can think of that will give you 3A+

tiges_ tendres

Re: Odd power supply request
« Reply #3 on: January 05, 2015, 08:18:04 PM »
Thanks to you both!

I'll check my parts bin for those regulators, and I believe I even have a laptop power supply that may hit those numbers.

I'll keep you posted on my results.

Try a little tenderness.

PRR

Re: Odd power supply request
« Reply #4 on: January 06, 2015, 04:35:15 PM »
>5v at 2A
> 10v at 1A


Very awkward.

I wonder if the "10V" is really a cheap 12V. This thing is a CD player (among other things), right? CD transports often ate 5V and 12V, standard PC voltages. However they would (usually) work with less of the 12V (perhaps slower, which seems to be a comment).

5V/12V supplies are or were VERY common for external PC drive cases.

As you are not sure this particular unit can eat 12V, and 2V is a slim drop for many regulators, I'd consider three 3A rectifier diodes in series between 12V and 10V. (I've run a few 3V systems on 5V this way.)

ACS

Re: Odd power supply request
« Reply #5 on: January 06, 2015, 06:25:50 PM »
Laptop P/S's are often 18-20 V, should should be fine regulating from that - but you will need to heat sink if drawing the full current!!

Curious thought on the 10V vs 12V though - certainly the first time I've seen 10V 'required'...

tiges_ tendres

Re: Odd power supply request
« Reply #6 on: January 21, 2015, 04:48:39 PM »


5V/12V supplies are or were VERY common for external PC drive cases.



Ah ha!

As it turns out, I have a power supply to connect to a hard drive that puts out 5v/12v at two amps.  If I drop the voltage on the twelve volt line, is there any danger of giving it the extra amp if the voltage is correct?
Try a little tenderness.

newperson

Re: Odd power supply request
« Reply #7 on: January 21, 2015, 05:04:27 PM »
Your item should pull the amps it needs.  So having more amps available should not matter.  When you plug it something into a wall you have 15-20 amps available for use, but most items will usually be pulling much much less.  If your item is broken and pulls too many amps the fuse should blow.

Is your new power supply 2 amps total or 2 amps per side?   You on KLOV?

« Last Edit: January 21, 2015, 05:07:25 PM by newperson »

tiges_ tendres

Re: Odd power supply request
« Reply #8 on: January 22, 2015, 06:38:38 PM »
Your item should pull the amps it needs.  So having more amps available should not matter.  When you plug it something into a wall you have 15-20 amps available for use, but most items will usually be pulling much much less.  If your item is broken and pulls too many amps the fuse should blow.

Is your new power supply 2 amps total or 2 amps per side?   You on KLOV?



I don't know what KLOV is.  I think the power supply is likely 2 amps total, now I think about it.  I'll have to double check?
Try a little tenderness.

newperson

Re: Odd power supply request
« Reply #9 on: January 22, 2015, 06:50:00 PM »
http://forums.arcade-museum.com/
Arcade forum.  You might find the part you are looking for there.