Hey guys,
I built and amp recently that runs off of 12vAC.
I want to use this amp in my car (12vDC). The amp draws a max 30-40Watts. I doubt using a bridge rectifier would be enough -> too much current.
How could I go about cheaply and effectively doing this?
Thanks!
I built and amp recently that runs off of 12vAC.
I want to use this amp in my car (12vDC). The amp draws a max 30-40Watts. I doubt using a bridge rectifier would be enough -> too much current.
How could I go about cheaply and effectively doing this?
Thanks!
It would be a good idea to give us details of the amp you have built and its power supply before expecting someone to give you advice.
Tony
Tony
Use a vibrator.
😀
I am sure he means a Vibrator, as used in early car radios to generate a HV AC supply from a 12V DC source ?. It is rather like a buzzer, which uses metal contacts to momentarily interrupt current flow, thus resulting in a buzzing noise.
SandyK
😀
I am sure he means a Vibrator, as used in early car radios to generate a HV AC supply from a 12V DC source ?. It is rather like a buzzer, which uses metal contacts to momentarily interrupt current flow, thus resulting in a buzzing noise.
SandyK
uh... Its a kit I bought at a local electronics store. its a stereo 30W RMS amp.
I'm using a 12v transformer now to take the mains voltage down to 12v.
What else would you need to know?
I'm using a 12v transformer now to take the mains voltage down to 12v.
What else would you need to know?
Cxrazy said:
Well there are a few possibilities here that rely on knowing how your amp functions.
Amplifiers run on DC, not AC, so what does the other part of the power supply on the amp look like? Is it a voltage doubler, or does it just make a single DC supply?
Going from DC -> AC -> DC in a car would be pointless if your amp just runs on a low voltage single supply. In that case you could just power it straight from the cars DC.
An externally hosted image should be here but it was not working when we last tested it.
Thats what it looks like. maybe it uses those diodes to rectify AC to DC.
Anyone?
OK, your amp needs a symmetrical DC supply of up to around +/- 16v. The only real way to accomplish this in a car is with a switch mode power supply.
Building a SMPS is far more complicated than your amp kit. See the link below for details on a SMPS for car audio use.
http://sound.westhost.com/project89.htm
Building a SMPS is far more complicated than your amp kit. See the link below for details on a SMPS for car audio use.
http://sound.westhost.com/project89.htm
I have a broken car amplifier.
Could I somehow salvage the powersupply from this? Building that SMPS is a bit over me tech level 😉
Could I somehow salvage the powersupply from this? Building that SMPS is a bit over me tech level 😉
As long as the power supply still works it should be possible. The voltage might be too high, in which case you can take some turns off the transformer to reduce it.
This amplifier can be run with a DC-DC converter. You will occasionally see the Vicor high power/high voltage converters on EBay, but the price is typically more than just buying a Class-D amplifier brick for auto uses from parts express. You can use the amplifier single ended as well -- just capacitatively couple the speaker output leads. NXP shows how to do this on their website. Leave the caps in, take out the diodes.
I think that about 10% of the members of this forum are old enough to remember vibrator power supplies used in tube radios for cars -- they were pretty darned noisy. An NE555 or SG3524 will do roughly the same thing.
I think that about 10% of the members of this forum are old enough to remember vibrator power supplies used in tube radios for cars -- they were pretty darned noisy. An NE555 or SG3524 will do roughly the same thing.
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