220v 0.5A converter help

[janosandi]

Hello guys
i have an ac source from a small generator
any idea to amplify it ?
like making a dc source & use it to supply 12 v to inverter ?
ur help will b appriciated

 

[kam1787]

your ac source; voltage? current? frequency?

and to supply: voltage? current? frequency?

 

[janosandi]

Morning
my source 220vac 0.5A max must be 50Hz
i want higher current
Thx for ur reply

 

[mrinalmani]

1. 230/12V transformer
2. Buck converter with a large input capacitor

 

[janosandi]

220/12v current ?
do i have enough ac current to drive this transformer ?

 

[mrinalmani]

For this rating, a good transformer should not pull in more that 50mA to 100mA of magnetization current. Even if it does, use a parallel capacitor at the primary to compensate the reactive power requirement. Capacitor should provide most of the VARs required.

I think a buck converter should do reasonably good.

 

[janosandi]

thx dear
i've searched for a buck converter circuit but i couldnt understand it fully
So i can use my 220v source to drive the converter then use the 12v to drive an inverter directly?
would u plz use a pic to explain it with the capacitors as u said?
thx for ur help

 

[mrinalmani]

See the attachment below.

 

[janosandi]

i didnt understand how to use this
the ac source to the left but wht can i do with the dc source on the left ?

 

[mrinalmani]

the ac source to the left but wht can i do with the dc source on the left ?

What do u mean?

 

[BradtheRad]

The coil in the buck converter cannot output greater current than goes into it.

This means if your power source is limited to just 0.5A...
Then a buck converter is limited to just 0.5A (that is, on a continual basis).

- - - Updated - - -

Hmmm...
Unless you interleave several buck converters. Run each at 10 or 20 percent duty cycle. This will require several inductors.

It may be more practical to use a single flyback converter, with a single transformer.

 

[FvM]

have an ac source from a small generator
any idea to amplify it ?

Most posts at Edaboard about "amplification" of an energy source are asking for some kind of "over-unity" or perpetual motion device, I fear it's also the case with this one.

Simple consideration. If you want 220V 0.5 A output, your generator must deliver at least 110 W plus a surcharge for conversion losses. Does it? What's the volt and ampere specification?

Energy storage in a battery for short time operation at higher power is possible nevertheless.

 

[janosandi]

thx for ur reply
im really confused of this
so its something impossible as i guess

 

[BradtheRad]

thx for ur reply
im really confused of this
so its something impossible as i guess

Not necessarily impossible as long as we are talking about stepping down voltage, in order to step up amperes.

A transformer is really your easiest, simplest solution.

And for all we know, you could hook up your generator to a 50 Hz 'wall wart' adapter, and it would output 12 V at 8 A. (Or about 100 W, as based on your generator spec of 220 V and 0.5 A, minus losses.)

However it is risky to rush into that. We would need to be sure that the generator runs full power at 50 Hz.
However suppose it runs full power at 40 Hz. This could cause the 50 Hz transformer to (a) saturate, and (b) carry overmuch current, and (c) overheat, and (d) become ruined. That is, if you are not careful.

Now suppose the generator puts out full power at 50 Hz, but less power at lower speeds. Then it is possible things would be all right when you run it at lower speeds into a 50 Hz transformer.
However it is impossible to predict anything without seeing a graph of voltage and current output, versus frequency.

I could be wrong of course, and someone who is more expert might have a different recommendation.

 

[BradtheRad]

If the right transformer cannot be found, then a flyback converter could be suitable.

This simulation shows simple methods to:
(a) Full-wave rectify and filter the 220 VAC from your generator,
and
(b) Feed the resulting DC to a step-down flyback.



Instead of the switch, you would put a transistor or mosfet.
The arrangement would need to be different than my simulation gives.

My simulation demonstrates concepts in a very simple manner. The values are ballpark figures. You would omit several of the resistors which are only there to allow the simulator to run smoothly.

The clock is any convenient pulse generator. It does not have to be 1 kHz, in fact it can run many times faster. It depends on the parameters of your transformer.

This project is not easy to design and construct.
There may be store-bought units available. One of those could be exactly what you need.