(help) Make a 13.8V 50 Amp continueous current

[jer3my]

Hi,

I have a milbert BaM235 car amp which is derived from david berning's EA230 home amp. I would like to use it at home and decided to make my own power supply. It needs a continueous 50 Amps of current and 13.8V. Can anyone help me with a schematics and some explanation?

Cheers

[kenpeter]

Car batteries usually charge at 14.5V from the alternator.
This can go on continuously and no harm to the batteries.
Higher than this, they start to lose water.

Very freshly charged with no load, might read your 13.8V
But 12V is more the nominal voltage for six lead/acid cells.

I suggest you simply use an actual car battery and charger.
The battery will provide more than ample regulation and
fill in the current peaks. No reason to make it complicated.

Do make sure the battery can vent gasses to outside.
And that nothing under it will be harmed if it leaks.
And that the point of last connection / first disconnect
(the place one might expect to see the spark, if any)
is always done far away, not at the battery posts!

[aardvarkash10]

50A seemed a bit excessive (!), so I checked at their website. It actually draws 5A at idle, supposedly 20A at full output. Kenpeter is onto it - a decent sized SLA battery (say, 20amphours)and regulated charger capable of around 8A continuous output should give you all you need. Unless you are running the amp wfo all the time in which case, perhaps you need a higher output amp?

[DigitalJunkie]

I rewound a Microwave Oven Transformer (MOT).

I cut the original secondary off,and wound my own secondaries (2x) with some 10AWG wire. Each secondary goes to it's own 35A bridge rectifier,and then the output of the rectifiers is paralleled,and filtered with some big caps.

Here's my really old writeup on it.
Monster MOT supply.

[Geek]

Car batteries in houses can go *BOOM!*

Use a sealed gel-cell for computer UPS duty.

DigitalJunkie's idea is the safest though

Cheers!

[aardvarkash10]

SLA batteries are no more likely to go "BOOM" than an amatuerly rewound MOT... Which explains why they are used as back-up power in many, many buildings world wide. ALso in security systems. But on the same tack, yes they MUST be well ventilated.

[jer3my]

thanks for the suggestion, but I kinda like not to have a car battery lying around in my listening room if I could help it. Any other way I could power this thing up for home use?

cheers

[DigitalJunkie]

Originally posted by aardvarkash10
SLA batteries are no more likely to go "BOOM" than an amatuerly rewound MOT... Which explains why they are used as back-up power in many, many buildings world wide. ALso in security systems. But on the same tack, yes they MUST be well ventilated.

Sealed Lead Acid batteries are relatively safe for use indoors. They are sealed,so they can't leak acid,and won't 'vent/out-gas' under normal use. (They will if you overcharge them.)

Flooded lead acid (like a car battery) is a bit of a danger.Not just the acid,but it will make (explosive) hydrogen gas when it is charged,which *must* be vented (outdoors).


Since the amp will only draw large currents during musical peaks,you might be able to 'get away' with a SLA battery (say 17AH,or something) and an old PC power supply,or battery charger.

[Geek]

Originally posted by aardvarkash10
SLA batteries are no more likely to go "BOOM" than an amatuerly rewound MOT... Which explains why they are used as back-up power in many, many buildings world wide. ALso in security systems. But on the same tack, yes they MUST be well ventilated.

I was referring to kenpeter's post, not yours

Cheers!

[jer3my]

Is it impossible to get a AC to DC converter to power it up?