Ok, I have another problem that popped up its little head. Refer to this thread for details of what i am talking about below... I bought a 13.5/30v AC to DC converter for use on my 600 watt amp. Of course running 13.5 isn’t enough to drive 2 12" woofers so I use the 30v. The 30v works fine although I am concerned about blowing something up (I think the amps input is only rated at max 20v. Also I am having trouble turning on/off the amp via the remote wire. It doesn’t seem to want to turn off when I disconnect 12v to the remote (it should turn off when no 12v is found on the remote wire). So is there any way I can use those diodes so that i can crank down the 30v (which is registering about ~25v when the amp is on without subs bumping) down to about 18v? I don’t even know that turning down the volts will have any impact on the amp turning on/off by the remote wire but will see. David
I have a feeling having one of those discapaiting a few hundred watts of heat is going to = toasty. Also it wont support enough current. The problem is going to be discapaiting the heat produced. You could do the other way round and step the 13V up to 18V. Look at Maxim they have some heavy duty power ICs
sure ill step it up to 18v instead of down. Can u provide me with examples of this? I always do better with pictures showing me what i need to do. David
Usually you use what is called a charge pump to increase the voltage. The problem I am having is finding a circuit which can handle the current your application is going to require. i can find ones which will supply 100W but not 600W. Your best bet would be to find a different AC-DC convertor.
Can you expalin the problem a bit better? I had a quick look at the other thread and didn't see much related. Then again having a cold doesn't help the brains. Are you trying to run a car amp off 18V? If so it in't going to be too happy with you. Second best method is to just get a power supply of the right voltage. Best method is to look through ebay on the music section and get a 600W PA amp which will kick a car amp across the floor and out the door anyday.
The converter i am using is from radioshack: 13.5v They do not carry any higher ones or i would have bought that one. My other post show how i used 3-4 dioids to lower the 5v current to 3v. I was wondering if i could do the same to the 30v current but i think someone said somthing about the heat that would generate. Like i said, i can anyways get an X10 addaptor for the wall plug and turn it on/off by that but i would be using the 30v side (again, which registers about 25v when hooked to the amp being off). David
Don't know about anyone else but I'm getting a little confused. Start again! This amp is a regular comercial type that you bought? If so I must have come with its own power supply? Are there any specs for it, such as supply voltage, currect draw, wattage? If the amp is rated at 600watts it doesn't mean it will need 600watts at supply. What are you wanting to supply the amp from? I'm guessing the converter you got is a wallwart type? Assuming the amp only needs a -30v and ground input then your best bet would be to buy a power converter to do a straight conversions from mains to the required DC. HTH
ok....here goes... The amp is a Jensen 4-channel 600watt amp that i am trying to hook up in my home with my theater system. This is all i can find on it since the amp is so old: This, of course, is a car amp that reqires at least 10-12v to it to even make one sub hit. I have 2 12" that i need to hook up to it. No, no car amp comes with its own power supply. Never seen that at all. I would give you all the specs in the world if i could find the manual but like i said, this is an old amp they do not make anymore. Since i want to have the two subs hooked off the amp, i am using it in my room for my theater system bass. Accordingly, i have the AC/DC converter for the wall socket to power the amp. I bought it at Radioshack. I posted the link to it on my last post above. Links are always nice to show me what power converter you are talking about. David
Well cars have 12v batterys, which goes upto around 14v when the engine is running. Lorries and trucks IIRC usually have 24v batterys, so in this case, it was probably designed not for cars. If its used in a car, it would have had a thing to step the 12v upto whatever it needs. Anyway for home use, I suggest you look at 24v battery chargers, they will probably be capable of the required current?
OK, well the 13.5/30VDC wallwart you got isn't going to be up to the job because it's only rated to 1A (1000mA). The similist way for you to work out the current it's going to draw in operation would probably be to get a car battery and wire it up. then measure the current it draws. (remember through not across) A cheap source for a PSU could be a car battery fast charger or mains powered jump starter.
does anyone see using the 30v (which again is only 25v once it hits the amp) as dangerous? it worked just fine with both subs hooked up and hitting using that one. Im not going to use a car batt in my home. David
What you are trying to do with a 30V power supply is make a smoke machine. As already stated it is a 12V amp, it can handle 14.4V, maybe even 15V if you are lucky. At 30V all you are doing it trying to blow it up. What you need is a 12V 600W supply. That is 12V at 50 Amps. Anythig smaller simply won't cut it. Now that is not the sort of power supply you can get from radioshack or whatever you have there. It is a custom built transformer i.e. expensive. Then you will need probably three 1Farad capacitors and at least a 100amp bridge rectifier. All up this is going to cost a lot more than buying a decient amplifier. If you are still keen to use this amp use the biggest 12V battery charger you can find and a deep cycle marine battery to power it. With an amp of this size I really wouldn't expect it to last 1-2hrs at best before the battery is flat. Even so you have still just paid more for the battery than the amp is worth. To sum up: It won't work.
PS. That power supply from Radioshack gives a grand total of 13watts of power. Where do you expect the other 587Watts to come from?
Well i did an exparement. I hooked it up (bridged) both of the subs to the 600 watt amp. I let about and hours worth of rap MP3's play on it and tested the volts at those different peaks and non-peaks. It only averaged about 12-20v at any given time. Check the status of the amp off and on for that whole hour and nothing seemed wrong with it. No funny smells, etc. The protection light never came on and both subs hit hard (like they would in a car). So to me, it works just fine using the 30v side. I can even power it on and off by the computers 12v line. So i guess problem solved. Thanks for the replys. David
The ac/dc converter should give 30Watts at 30V As its a car amp there is a fair bet it has some serious smoothing and voltage regulation, lets face it a cars 12V is anything but a nice smooth 12V. At 30V whatever is doing the regulation will prolly only last a few days/weeks. Possibly longer as it is rated to take up to 20V, but I wouldn't give it too long as its regulation circuits are only going to convert it to 12V anyway, so they heat up and die. *shrug* but if that is working fine to you then thats just gravy.
It sounds like the amps draw is pulling the supply voltage down to something like 15V when it is running. If the supply is only at 25V when the amp is off, it sounds like you have a rubbish power supply, Either that, or it is unregulated. Also, using a bug battery charger is a good idea, but car battery chargers have no voltage smoothing (eg, capacitors), but rather just a big transformer and a rectifier, so you would need a couple of big ones to get yourself a good clean supply. Also, bear in mind that to get that much power out of 12V, every car amp has to have some sort of dc-dc converter in it to increase the supply voltage. Not to go into details, but is is possible that there is no harm in running the amp at 30 (25)V. It just depends on what the components on the input side of the converter are rated for.
