I need the following circuits.

[Thabto]

I am requesting for schematics for the following projects, I need to build circuits with (easy to find components):
(1.) 100watts(or higher) x 2 audio amplifier
(2.) AC voltage regulator (220volts), I need this circuit to control AC votage so that it does not exceed 220v, even if I am using a very unstable power source.
Thank you.

[stj]

Re: I need the following circuits.

1 can be done with a single amp chip these days - look at ST's website for starters.

2 is very difficult.
you either need to go DC and then use an invertor to make it AC again,
or you need a special transformer with 3 windings.
a primary, a secondary and special "control" winding that can be used to dampen the field and lower the output.
you also need a special circuit to control it - similar "counter-field" systems are used on very large generators.

infact there are 3 ways used in industry.

the invertor design - like a UPS but without the big battery's
the special transformer system,
and the flywheel systems - dont ask and dont try it!!!

[Wizard]

Re: I need the following circuits.

Variac Autotransformer (that heavy thing with knob on top).

Cheers, Wizard

[PlainBill]

Re: I need the following circuits.

I am requesting for schematics for the following projects, I need to build circuits with (easy to find components):
(1.) 100watts(or higher) x 2 audio amplifier
(2.) AC voltage regulator (220volts), I need this circuit to control AC votage so that it does not exceed 220v, even if I am using a very unstable power source.
Thank you.

1 is easy and has already been explained. I doubt you can build '2' economically. There are two approaches with commercial products. The first has already been mentioned - a 220 Volt UPS. Use one with a sinusoidal output for maximum accuracy.

The second is a Constant Voltage Transformer. Sola has a line of them. Their advantage is they are much simpler than the UPS approach.

PlainBill

[Wizard]

Re: I need the following circuits.

CVT only works in narrow range of current, very lossy, under or over current throiugh this and transformer comes out of saturation and it comes out of regulation or unstablity. Not suitable due to open gap in one core section is the reason for narrow range of watt/current capacity. This is reason why variac transformer is recommended. Just set it to specific AC voltage and forget, and works on varying current but voltage stays solid.

There's a section on this one, remember it has cap, core shunt and core gap to form the CVT design. I have seen this particular design, simply works but not efficient at different loads.

http://en.wikipedia.org/wiki/Voltage_regulator

Cheers, Wizard

[PlainBill]

Re: I need the following circuits.

CVT only works in narrow range of current, very lossy, under or over current throiugh this and transformer comes out of saturation and it comes out of regulation or unstablity. Not suitable due to open gap in one core section is the reason for narrow range of watt/current capacity. This is reason why variac transformer is recommended. Just set it to specific AC voltage and forget, and works on varying current but voltage stays solid.

There's a section on this one, remember it has cap, core shunt and core gap to form the CVT design. I have seen this particular design, simply works but not efficient at different loads.

http://en.wikipedia.org/wiki/Voltage_regulator

Cheers, Wizard

With all due respect, read the original request.

I need this circuit to control AC votage so that it does not exceed 220v, even if I am using a very unstable power source.

While a variac can be used to adjust the output voltage, the ratio of input / output voltages will remain constant. Ordinarily, that should be no problem. However, it appears the OP is in an area where line voltage is subject to wide variations.

PlainBill

[Agent24]

Re: I need the following circuits.

If your line condition is bad you could buy a line conditioner or UPS

While it should be possible to make both, it may be better to purchase one for safety (unless you know what you're doing with mains wiring in which case go ahead)

I think a UPS would be the better choice though. If you want "perfect" power then get an 'Online UPS'