I need more volts in my car.

[Dan2]

Hi guys.
i am very new to this site site - and i'm a complete amateur at electronics - most of the stuff i know i have learn't by myself!!

Anyway, here's my problem - i have a house amp in my room that im not using and i want to use it in my car. it uses a single 50v transformer. can anyone help me to build somthing to get the 50v i need from a 12v car battery??

 

[Magura]

3 extra batteries

Magura

 

[Eva]

You can scale up those 12V from the car with a relatively simple SMPS. That topic has been already discussed several times, and several people have built their own PSUs. There are a lot of posts with explanations, just use the search engine.

 

[sndscientist]

you have alot of different options, alot of it depends on your financial situation.

for example you can buy a 750 watt vector power inverter (only said a brand name cause they seem to be the most durable with inductive loads) for about $100 <usd>. however if the amplifier in question requires a sine wave such as the qsc powerlight series and the older model carvers, then simple inverters and smps may pose a problem.

depending on the vehicle in question a modification to the alternator may be an option. in my 85 ford E150 the voltage regulator and alternator were modified to produce between 90 and 110 vac 3 phase. that is an option but with that you need a high current recitfier and shunt regulator to limit the voltage to the charging system of the car.


if you choose to attempt to build something yourself and you amplifier doesn't require a sine wave and isn't really frequency dependant. such as if the transformer just dumps into a bridge recitfier and a few giant storage caps, your possabilities are almost endless.

just out of curiosity what are the rail voltages of the output section? does the rest of the amp just reduce the rail voltages to other usable levels or are there more windings and other taps on the transformer?

Adrian

 

[Dan2]

Well. like i said i'm an ameteur, so i'd rather not mess around with the altenater. the amp i want to use is pretty old (actually REALLY old). It just has a 50v dc input, bass, treble, volume control and the speaker output. there used to be two amps connected to the one transformer, but the one blew so im just using the remaining one. i want to use this amp cos it would be really easy to install if i just sort out the power supply.

 

[Dark Harroth]

Well. like i said i'm an ameteur, so i'd rather not mess around with the altenater.

That is a little bit contradictory, if you ask me.
You said, that you had a mains-transformer for the amp. Just buy a suitable alternator and connect it with the transformer. It's many times simpler, than building a smps of your own.

 

[sndscientist]

IMO, building a smps, while being a better learning experience, would prove much harder than doing a simple alternator modification or adding a power inverter. however for todays newer and more complicated vehicles i suppose alternator modifications are pretty difficult.

 

[anatech]

I don't suppose you'd consider buying a car amp (with two working channels)? It might be less expensive at the end of the day.

-Chris

 

[Dan2]

Well i have a few car amps, but they only push out 17 watts per channel, and they're not brigable. If i could bridge them, there might just be enough power - so can i build a bridge circuit quite easily or not??

I'm not interested in buying a power inverter cause it costs about the same as a car amp!!!

Thanks guys

 

[anatech]

Do your car amps have a transformer inside them? If they are small with chips against the heatsink, they may already be bridged. Both speaker leads would have signal, and may be 6~7 VDC above ground.
-Chris

 

[Eva]

Most of these 17W car amplifiers are already bridged internally, so no further bridging is posible.

 

[sndscientist]

i take it the 17 watt specials your talking about are the one chip wonders. if they are you can't bridge them. the entire component array is on the chip in's and outs as well

 

[anatech]

As I stated before, they are already bridged. Often they are also advertised in the North American market as 20W or 25W per channel. Typically a small case, with or without an EQ on the front.

How's that for dating myself?

-Chris

 

[Dan2]

the amp i have is a 4 channel amp. it says 50w x4 but the specs say 17.4w rms - trust me, they are not 50w rms amps!!! so why the different wattages?? Just as a matter of interest.

as for my other amp, i think im just gonna get a more powerfull car amp - it end up being cheaper.

thanks a million for all the advice

 

[xplod1236]

50 x 4 means 50 watts PEAK per channel, not rms

 

[anatech]

It's all marketing and what they can get away with.

-Chris