# How Works upper volt in car Amplifier???

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#### Dj BASS AMP

How Works upper volt in car Amplifier???
i need it in Circuit and image

(the upper volt is up from 12V in the car AMPLIFIER to high volts (30V + )

thanks alll !!!!!!!!!!!!....

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#### Lisandro_P

It's a special powerssupply called "switchmode". The basic idea is that you generate an AC wave from the car's battery DC, increase it's voltage via a (usually small) transformer and then rectify it again with a diode bridge to get DC again, but at a higher voltage. Usually the AC wave is square and high frequency, so the efficiency of this kind of circuits it's rather high (90% is not uncommon), yet, they're NOT trivial to design or build.

Rod Elliot ( www.sound.westhost.com ) had a few very good articles and proyects on these kind of psu's.

#### Dj BASS AMP

I need Circuit to...

#### jackinnj

This will give you an idea

The pdf is from On-Semi (formerly Motorola) of a high current, high voltage "off-line" switcher. Off-line switchers, as the name implies, take the juice right out of the wall socket and convert it to DC. The reason that I mention this one is that a PCB layout is given. Furthermore, you can omit the rectifier on the input since you will be taking 12VDC from the battery, and of course you will have to change the transformer, etc.

http://www.onsemi.com/pub/Collateral/MC33362-D.PDF

Before you get started building a switcher, you should read the tutorials on National Semi and Linear Technology. Furthermore, Nat Semi has some easy to use design software on their site.

http://www.linear.com/pdf/an73f.pdf
http://www.national.com/ds/LM/LM2587.pdf

International Rectifier has a good tutorial on switching ps transformer design on their website:
http://www.irf.com/technical-info/appnotes/an-1024.pdf

Pay very close attention to specifications of all diodes, inductors, capacitors etc.

Why isn't TI mentioned here? I find their website unuseable. I was once a fan of Unitrode parts, but they have made a salad of the information. They are the largest company in the biz, however. Pity.

#### gromanswe

Before Starting.

Before Starting to build a "not trivial" switchmode PSU,
you might be interested to know,
that there are a bunch of Step up Regulators
that come in form of ICs.
They can be for one voltage or be Adjustable.

Some examples:
just paste those two lines, one at the time,

the first is for max 3A max 37 volt out
the other can deliver 5A

I am sure the other guys here can give some more ICs

gromanswe
switching up

#### Dj BASS AMP

thanks alllllllllllllllll !!!!!!!!!!!!

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