i have a problam.... i have a car amp and i want...

Status
Not open for further replies.
Jump to Latest
#25
Peak Vs Average Power.

Interestingly a rig I used to use for repairing/bench testing big car audio amps was a 12V 2A supply with a 60,000 uFd cap on the output.
This would supply enough current for statup, and enough average (2A) current to run most amps to high level quite ok.
Nowadays I use a car battery size sealed lead acid gel cell battery for car audio testing.

Eric.
 
#27
DJ, a car battery will work fine, although if your amp draws 65A running at full power, the charge on your 20Ah battery will last just over 15 minutes. It will, of course, last substantially longer at lower powers, but I would consider getting a larger capacity battery. If you omit the large reservoir capacitors, you could afford a larger battery - this will be much more worthwile than 0.1F of capacitance.

Hope this helps,
Tim.
 
#33
what is the rule on switching power supplies? Can you put them in parallel?
decent power supplies are like $20 bucks now, and will deliver 10-15 amps at 12v.. can you place their outputs in parallel? I am assuming so, since you can get redundant supplies in servers that are pretyt much in parallel?
 
#34
It's a little more complex than that and there is a liberal amount of electronics in redundant power supplies to ensure safe operation. Also, if using computer power supplies, you will often need to load some of the other rails (usually 3.3V and 5V) or the supply will not function correctly or could even blow up!
 
#38
Hi DJ Bass Amp

I agree with Mrfeedback and audiofreak about using a computer switchmode powersupply. Only not a PC but Mainframe supply.
I have some mainframe supplies that handle 30 amps continuous and 40 peak at 12 volts. They also have an adustment so maybe get it up to 13 volts? They measure 12" x 8" x 5" and weigh about 5kgs.
Why not ring all the computer companies and see if you can get through to the service dept or even the parts guys and try score some old surplus gear. If this fails try computer surplus guys, most old mainframes get stripped for metal by metal scrap yards and they give this stuf away. These guys also have very very big electrolytics for cheap.
Happy hunting.
 
#40
you need more, 65A is ok if you amp would have 100% efficiency, but it doesnt, except if you will run it at lower wattage.. there will be A LOT of losses, first from you line to 12V, then switch to amp rail, amp losses - a lot of heat..
 
Status
Not open for further replies.
Top Bottom