HOMEBREW HELP?????

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BRIAN KB0CIG
Posts: 12
Joined: Fri Sep 30, 2011 10:04 pm
Location: NEW YORK

HOMEBREW HELP?????

Post by BRIAN KB0CIG »

I HAVE TWO 12 VOLT POWER SUPPLIES ONE A 10 AMP AND THE OTHER A 12 AMP..I NEED A 22 AMP SUPPLY..HOW DO I GO ABOUT MAKING THESE TWO WORK FOR 22 AMP? PLEASE , NO INSULTING REPLIES, I ALREADY FEEL BAD ENOUGH..TNX, BRIAN KB0CIG

BTW, YOU CAN EMAIL INFO IF YOU LIKE
KB0CIG
k9yli
Posts: 229
Joined: Fri Aug 12, 2005 11:35 pm
Location: northwest wisconsin

Post by k9yli »

Basically you need a circuit to isolate the two outputs from each other so , if one is slightly lower in voltage, it doesn't mess with the others regulator, trying to compensate. With the output of that circuit to the load.

In a word,, it can't be done........... with out some serious engineering..
plus you need some protection circuitry so that if one supply fails
it will shut down the other.

Yes you can just hook them in parallel like two batteries and you can draw the 22 amps..
to do this you would need to VERY accurately adjust both supplys individually to exactly the same out put voltage,, and since a regulator is quite accurate,,
we are talking maybe to at least 2 decimal places.
as in 13.801 volts.
And even with that done, they might still vary slightly with load and thus be offset slightly anyway.

good luck ..
BRIAN KB0CIG
Posts: 12
Joined: Fri Sep 30, 2011 10:04 pm
Location: NEW YORK

THANK YOU.

Post by BRIAN KB0CIG »

k9yli wrote:Basically you need a circuit to isolate the two outputs from each other so , if one is slightly lower in voltage, it doesn't mess with the others regulator, trying to compensate. With the output of that circuit to the load.

In a word,, it can't be done........... with out some serious engineering..
plus you need some protection circuitry so that if one supply fails
it will shut down the other.

Yes you can just hook them in parallel like two batteries and you can draw the 22 amps..
to do this you would need to VERY accurately adjust both supplys individually to exactly the same out put voltage,, and since a regulator is quite accurate,,
we are talking maybe to at least 2 decimal places.
as in 13.801 volts.
And even with that done, they might still vary slightly with load and thus be offset slightly anyway.

good luck ..
WILL NEED TO LOOK AT NEXT HAMFEST FOR NEEDED AMP POWER SUPPLY..MANY THANKS
KB0CIG
ae6zw
Posts: 7
Joined: Wed Nov 23, 2011 9:04 pm
Location: Westminster, CA

Re: HOMEBREW HELP?????

Post by ae6zw »

I have same problem as you do, except mine is 4 A supply, so I bought deep cycle marine battery from walmart, and charges it constantly through xx ohm resister to keep current low enough for power supply, I set power supply voltage to around 14 V, Deep cycle Battery can supply 20A easily to my HF radio, no problem at all 10 A 2 meter radio, it also work as emergency back up power also, I also added reverse current protection diode between power supply and battery just in case. so battery power does not go back into power supply.
k9yli
Posts: 229
Joined: Fri Aug 12, 2005 11:35 pm
Location: northwest wisconsin

Post by k9yli »

for a couple years I ran my TS180 on a regular car battery,, old one that wasnt up to reliable starting..

hooke to a 15+ amp EICO battery substute...
adjusted output to about 8 amps..
as a battery eliminator and not a charger the output is filtered

( I have 4 of them ) handy in shop to run automotive stuff on the bench.
check trailer light wireing etc.

dont really need a deep cycle.
and yes I used it in the house.. no problem with hydrogen out gassing.
small amount in this use. dissipates easily..
WD4IFR
Posts: 1
Joined: Wed Jan 11, 2012 11:59 pm
Location: Mason, TN

Use a battery "buffer" to get the amperage you nee

Post by WD4IFR »

You can use a common practice used in the telephone industry to get more amperage. Simply connect both power supplies in parallel to one or two batteries. that are hooked up in parallel. Use the same positive and negative to supply your radio. The only "catch" is that the power supplies should to set up to put out the same voltage. If you have to, you can use one power supply to keep the battery "floating" and utilize the battery to provide your 22 amp supply as long as the battery can supply it before needed to recharge.

Dale
WD4IFR
WD4IFR -- Flying with Amateur Radio. Listen for us on your repeater or on 40 and 80 meters.
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