Hi all, Im calling all the electrical guru's I would like to power a car amplifier with a 450Watt psu putting out 34amps on its 12V rail. I have done alot of research and found that it is possible, but i want to add a few things to the mix like a 1 farad capacitor, I have found this site where a person has already done it, just not sure how he was able to do it, some clarity would really help me, heres the link, http://www.techidiots.net/notes/car-amp-project i was also thinking of using a lighting switching power supply that puts out 12V 30Amp and a Max of 350Watts, what is the biggest amp that i could power and really give it the beans(push hard) I was thinking about a 2/4 channel 700w calibra amplifier. I would like to run a 800Watt 15" SVC subwoofer. Do you think it is possible? Thank you for your time and efford
I have done similiar in years past....heres what I suggest, from a tested a proven method. Get the biggest power supply you can afford. The more amperage on a continuous basis the better.... Feed this to a battery or two, then power your amps off this.... Mind the voltage.....I dont suggest a cap for this. batteries will give you far better results. I ran about 2Kw like this at the house years ago, although with a astron 50 amp power supply and 2 batteries, crank up time was good for about 15 minutes at full bore....turned down and not raping the system....about 1 hour. the lower the volume the easier it is for the power suppy to keep up....its an RMS current draw thing
Well i have found a power supply that has a 30amp @ 12v constant and want to run them both in parallel, I want to power a Ice power 1200watt amplifier it has 2x 20Amp fuses, I if i run the 2 psu's in parallel i will get 50 odd amps constant, the reason for the cap is just incase i hit a huge bass track and i am drawing the living day lights out of the amp the cap with just help the psu's not to shut off due to over load, any other ways you have known others to do? other than using batteries. many thanks
again....use a battery.... even a small one. amp will be much happier. heck, you can get a small car battery for 40 bucks or so....whats a cap cost? you do the math
I'd be surprised if you can run two powersupplies in parrallel without problems. It would be like running two alternators in parrallel. In either case, the small differences in the output voltage of each psu, are shorted out = bad! The other thing is you can't expect any psu to happily run at it's maximum, so you'd want a decent brand psu with around 40amps capacity on a single output rail. Caps are great for surges when you can supply them with enough current. A cap will try to maintain voltage during spikes, but then it also wants to draw power to recharge, it would basically drag out any power surges, to maintain voltage/sound quality, by increasing current. So in other words, overloads will be more likely with cap. A regular car battery will behave in basically the same way, but they aren't as low resistance as a cap, so just a bit less smoothing for the amp voltage, but less chance of overloading the psu.
ok, If my amp has 2x 20 amp fuses, how much power do i need to power the amp, the amp will very rarely be pushed hard as its in a house in a built up area, I would not like to use a battery as it adds a stupid amount of weight, I came across a guy that has used a cap and a switching power supply to power a car amp, here is the link to Youtube, Please try make sense of what he is doing. thanks again Link: --link--
So you are using a car audio amp for home audio....great. so what does the weight of a car battery matter? I have a few home audio amps that wiegh MORE than a car battery... Dynamic peaks will exceed the 40 amps of the fuses at times...just because you have 40 amps worth of fuses does NOT mean that is the max it will draw...fuses have a factor in them that allows them to exceed the current rating for "x" amount of time. not getting into the logistics of this right now... I understand the video, ya....a simple method to charge a cap. an amplifier already has caps in it, why add another? the peak instantaneous current needed will be far better provided by a battery than a cap....thats it, plain and simple.
a normal sealed dry cell battery will not be able to last very long if you charge and discharge it rapidly, so i would need a wet cell battery from a car, like a full size car battery. dont think thats going to be very convenient if i want to host a party at a mates house and need my sound system.
Fair enough. The cap will increase the load on the pc psu, as I explained above, which might just mean that perhaps you'd need a 500w psu instead of a 400w psu if you had used a car battery... don't expect more than about ~250w of sound ouput in either case however, maybe less, it all depends on how efficient your amp is, but that might be enough power? If you use no cap or battery, I'd still go for at least a quality 500w psu btw, and if you were to use a quality 400w psu, don't expect over 200w total sound output, etc. If you're going to host parties, I'd sell the car amp if neccessary to put some cash towards a proper home amp setup, which will be much more efficient and professional.
