12V DC to 120V AC IMPORTANT!!

Thread Starter

badrove

Joined Mar 18, 2008
12
Hello,

I am loking for a circuitry to generate an alternatif signal (about 120 volts AC) but i have just a 12VDC alimentation.

the output frequency should be 100KHz.

Thanks for you
 

Søren

Joined Sep 2, 2006
472
Hi,

Thanks for you
Usually I have this effect on women only ;)


Please don't mark your post with "IMPORTANT", that only makes people NOT wanna answer. Any post is important to one who needs an answer, but not really very important to the ones able to give the answer.

Personally, I have a tendency to filter out such posts as well, but a quick answer would be: "Hook up a 555 to a ferrite transformer wound for the purpose".

(See, even unintentional flattery gets you somewhere ;))
 

Wendy

Joined Mar 24, 2008
23,415
Here is how I would do it...



I have never built this circuit. There may be traps or problems I haven't anticipated, which is why prototypes are built.

Unless we are talking a light load, the transistors will need heat sinked. This circuit should put out a substantial amount of current, so normal safety precautions should be take for high voltages.
 

SgtWookie

Joined Jul 17, 2007
22,230
Interesting circuit, Bill.

Just one thing - I recently was reading about a circuit similar to yours; a fellow tried to make the circuit more simple by eliminating the base resistors from the transistors forming the H-bridge; it didn't work after that.
[eta] Found the link to that similar circuit: http://www.solarbotics.net/library/circuits/driver_4varHbridge.html

A wild guess (actually, 12v/100mA, half of the current capacity of a bipolar 555) tells me that a minimum of 120 Ohms is needed on the base of each transistor.
 

Wendy

Joined Mar 24, 2008
23,415
Interesting circuit, Bill.

Just one thing - I recently was reading about a circuit similar to yours; a fellow tried to make the circuit more simple by eliminating the base resistors from the transistors forming the H-bridge; it didn't work after that.

There is one big difference between circuits, the one I drew is an emitter follower design, no resistors needed.
 
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