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
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
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!
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!
...and I can arc weld with it too!!!
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?
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?
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.
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.
Car batteries in houses can go *BOOM!* Use a sealed gel-cell for computer UPS duty.
DigitalJunkie's idea is the safest though 🙂
Cheers!
sorry geek but -
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.
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.
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
cheers
Re: sorry geek but -
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.
aardvarkash10 said:
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.
Danger! Danger, Will Robinson!
Hi,
Sealed lead acid batteries need a different charger than normal batteries!!! Constant current I believe.
I cooked one using a normal charger. It went hot and started to bulge a bit. I can now see cracks in it.
Careful.
Serge
Hi,
Sealed lead acid batteries need a different charger than normal batteries!!! Constant current I believe.
I cooked one using a normal charger. It went hot and started to bulge a bit. I can now see cracks in it.
Careful.
Serge
Re: Danger! Danger, Will Robinson!
Woah! I learned something new today 😱
Cheers!
Serge66 said:Hi,
Sealed lead acid batteries need a different charger than normal batteries!!! Constant current I believe.
I cooked one using a normal charger. It went hot and started to bulge a bit. I can now see cracks in it.
Careful.
Serge
Woah! I learned something new today 😱
Cheers!
nope - nothing special, just regulation
the battery bulged because hte chage voltage rose too high. Any good quality battery charger will be regulated for voltage, so that won't be an issue.
If you use a "constant current"charger, you are sure to blow the battery up - think about what constant current implies if the battery is already fully charged...
To our #1 poster, in practical terms, no, a straight battery charger will NOT power your amp - it isn't designed for hte transient loads music requires. Use a sealed Lead Acid (SLA) battery (cheap and readily available) and a reasonable quality regulated battery charger. It will not kill you...
Apologies to Geek for my misplaced chargrin! Love your website btw...
the battery bulged because hte chage voltage rose too high. Any good quality battery charger will be regulated for voltage, so that won't be an issue.
If you use a "constant current"charger, you are sure to blow the battery up - think about what constant current implies if the battery is already fully charged...
To our #1 poster, in practical terms, no, a straight battery charger will NOT power your amp - it isn't designed for hte transient loads music requires. Use a sealed Lead Acid (SLA) battery (cheap and readily available) and a reasonable quality regulated battery charger. It will not kill you...
Apologies to Geek for my misplaced chargrin! Love your website btw...
The Unitrode UC2906 / UC3906 is expressly designed for the charging and maintaining charge of sealed lead acid batteries.
It's been around a long time.
Win W5JAG
It's been around a long time.
Win W5JAG
Sure,You could use a 12V power supply,something similar to this:
http://cgi.ebay.com/12v-Power-Supply-13-5v-dc-26A-Adjustable-5-12vdc_W0QQitemZ370096077213
That's just the first thing that popped up on a quick search,I'm sure you can find a reasonable supply at a good price if you look a bit.
Here's another:
http://cgi.ebay.com/NEW-PYRAMID-35-AMP-SCANNER-HAM-CB-RADIO-POWER-SUPPLY-NR_W0QQitemZ120323812489
http://cgi.ebay.com/12v-Power-Supply-13-5v-dc-26A-Adjustable-5-12vdc_W0QQitemZ370096077213
That's just the first thing that popped up on a quick search,I'm sure you can find a reasonable supply at a good price if you look a bit.
Here's another:
http://cgi.ebay.com/NEW-PYRAMID-35-AMP-SCANNER-HAM-CB-RADIO-POWER-SUPPLY-NR_W0QQitemZ120323812489
Well, you can use a big bench supply, like a 13.6V, 80A Pyramid for ham radio and have a few farads of capacitance across the output for bass transients:
http://www.claysradioshop.com/pyr-ps86kx.html
Cheers!
**edit**
Heh... simulpost Pat
http://www.claysradioshop.com/pyr-ps86kx.html
Cheers!
**edit**
Heh... simulpost Pat
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