Yes, Painttoad. You can also use parallel or series driver chaining to form any ohm you want. The load on the amp is really not an issue. As long as you know what you are doing.

yeah,i understand,i'm series parallel on my subs.
i just thought it was funny the way it was stated,they weren't bad or cheap for what they were .

but i do think the load on the amp is an issue.
for whatever reason our more electronically inclined outlaws can give us i think the easier an amp can work (load) the better it can perform it's job.car or home!

The best place to start would be with any information the amp manufacturer can provide, especially schematics. A repair manual, if the manufacturer even prints one, is ideal since they usually include a pictorial diagram of the circuit layout, the schematic drawings and parts lists. Sometimes they even include a little circuit theory as far as the design being used. If the manufacturer isn't cooperative in releasing this kind of info, and many times they aren't, if you are friendly with a dealer they may let you have a peek at a drawing or two. Yeah a simple voltmeter can measure rail voltages and some algebra will get you in the ball park but there is nothing better than knowing just what the original designer had in mind.

While I have been building and modifying equipment for quite a few years, no, I haven't done anything exactly like this. This wouldn't be a real exotic project but I am a little concerned about the sheer size of the power supply (electrically speaking) for a first time DIY project. It is usually better to start with something a little smaller. Power supplies of this size can put you on your backside (or worse) if you aren't careful. You may want to hit the library first for a few books on basic electronics as well as power supply design. Here's a link to a DIY audio forum where you might lurk around or post a few questions as well.

I'm heading out of town for the holiday weekend shortly so I won't be checking this thread again until Sunday night or Monday. Have a Happy Thanksgiving everyone!

lots of posting on this topic today...

it is a waste of your time converting a car amp over to home use, but it is your time, so waste it.

it is not nearly as complicated as you seem to be thinking it is. they make ac to dc power converters, you just have to find one that outputs 14.4v. though i think they are expensive...

the performance of car amplifiers is far inferior to home amplifiers in regards to quality, low distortion wattage. car amps are made for different circumstances and with different goals in mind. their application to home use, while feasible, is impratical.

if you are attempting this project for your own interest, then have fun. if you are doing this as a permanent solution, then you are off your rocker.

either way, good luck with it, and have a good thanksgiving everyone. i dont really have anything else to say about this, but there was no need to be rude in your post re: my statement endoftheday.

good turkey day all!!!!

A power transformer that has a 120VAC rms primary and a secondary voltage of about 11.3VAC rms (about, to allow for two diode voltage drops), a diode bridge rated to handle tens of amps of currnet and some large electrolytic and film filter capacitors will make a basic 14.4VDC power supply. A power switch, fuse, and indicator light for the primary of the transformer would be nice also. A safe case, with venitlation, would be nice, too.

Beings this basic supply is not regulated (a suitable regulator circuit will add a lot to the cost), significant ripple voltage will exist on the DC voltage. This ripple voltage will increase as the load on the supply increases (playing the amp and speakers louder).

In order for this ripple voltage to not be heard as a hum in the speakers, the amp's DC-to-DC converter (to generate the higher DC voltage(s) that the amp circuit itself needs) needs to have a good (high) power supply rejection ratio (PSRR), which is the circuit's ability to reject variations in the input 14.4VDC and just do it's job. The amp itself should have a high PSRR, and probably will if it is a high feedback design.

Paul

Hello Paul

Will this transformer work for the 100 amperes DC power supply?

It shows second voltage 30V+30V. What does it mean?

Where can I buy diode bridge and large electrolytic, film filter capacitors?

Thanks

well, there you have it ,looks like you're on your way.keep us posted,i'll follow and throw my 2 cents in when needed.
good luck!

OK, I looked at the web page for that transformer.

"It shows second voltage 30V+30V. What does it mean?"

This means that there are two secondary windings, each putting out 30VAC rms when the primary windings, of which there are two, are connected to 115VAC rms.

In your case, 30VAC is way too much. WAY too much as in fry your helpless car ams big time.

If you connect the primary windings in series (and the secondary windings in parallel) observing the proper polarities, then the secondary voltage will be 15VAC rms. This is still too much. This would give about 20VDC to the car amp. Poof!

I think one of the other transformers that have secondary voltage ratings of 25v, will be more suitable. If their primary windings are connected in series, then the secondary voltage will be 12.5VAC rms. Allowing for two diode drops due to the bridge rectifier, the DC voltage will be in the neighborhood of 16VDC. This may be too high for your amp, maybe not. It depends on what your car amp is rated for in regards to maximum voltage.

Parts Exprss also had diode bridges, but the highest current rating (continuous) was 25 amps, but I would want at least twice this. Other supply houses, such as Mouser or DigiKey may have higher rated ones.

As far as electrolytic caps, you could use the same cap that is offered for use in car amp installations. If you have a car cap, use it, otherwise, just bring $$$. Mouser or DigiKey (or Newark Electronics, or Allied Electroncs, or ...) would also have these. 20V 100,000UF would be a good starting point as far as capacitor value goes.

Paul