This post has been deleted.

: Hi,
: How change a DC to AC?
:



ok, I will explain more...

For change a AC voltage to DC voltage, you have just to add 2 Del but if I want change a DC voltage to AC voltage? How to do this?

Do you have any suggestion?

Thanks

: : Hi,
: : How change a DC to AC?
: :
: ok, I will explain more...
:
: For change a AC voltage to DC voltage, you have just to add 2 Del but if I want change a DC voltage to AC voltage? How to do this?
:
: Do you have any suggestion?
:
: Thanks
:

Hi!
I have never heard of a "Del", but I suppose you mean a diode and a capacitor, and yes that is easy. But making AC out of DC is not so easy. The first choise you have to make is wich kind of AC you need to generate.
-Square-Wave is of course easiest, and in this case all you need is two transistors controlled by a oscillator. But a square-wave contains too many odd harmonics in some cases when the equipment is really made for sinusodal AC.

-Low pass filtered Square-wave is the same as the above but with a low pass LC filter to simply try to remove the odd harmonics, but this isn't effective unless you use quite large filters.

-A LP-filtered Pulse width modulated signal will be easier to filter and will provide a decent siusodal AC. The PWM pulse is made out of several pulses per half period, short pulses in the begining of the half period when the output voltage shall be low, longer pulses in the middle of the half period when the output voltage shall be higher, and in the end of the half period shortening pulses again, then for the second half period you do the same thing but with inverted output voltage.

DC/AC converting is full of mistakes to be made, if you also intend to boost the output voltage by high frequency transforming, then you will discover new problems that you haven't even heard of before, but you might gain a lot of useful knowledge.

/Tomas

hmmm,
Can you send me a shemas please because Im not very good in english and I not very good in electronics.

Send me a shemas please: ketchup.inc@caramail.com


Thx...

: hmmm,
: Can you send me a shemas please because Im not very good in english and I not very good in electronics.
:
: Send me a shemas please: ketchup.inc@caramail.com
:
Hi!
This isn't one of my own schematics, I just made a quick search for you, so I can't guarantee the performance of this converter. Actually I can tell you that the output voltage will depend on the load, as there is no output voltage regulation what so ever in this design. You should add a (5A?) fuse on the input line as there isn't any short circuit protection besides the limitation of Hfe in the power transistors. The output frequency of this converter isn't very stable either, but it is a simple square-wave design that I think might suite you.

If you like a lower/higher output voltage, (you use 230V in france don't you?) then you can simply use another transformer. If you exceed the current rating of the transformer you use, it might saturate and damage the output transistors.

PLEASE BE CAREFUL AS THIS DESIGN WILL OUTPUT HIGH VOLTAGES!!

/Tomas

Check out:
http://www.interq.or.jp/japan/se-inoue/e_ckt8.htm

THANK YOU MAN !!!! YOU HAVE MADE MY DAY !!