Generate 50 hz square wave

[blowouter]

i know there are alot of methods to generate square wave from sinewave
i want to generate square wave from ac mains supply with 50 hz
ac input voltage after transformer will be 12 volts

 

[ronv]

Squre wave

Maybe a comparator like this.

 

[MikeMl]

i know there are alot of methods to generate square wave from sinewave
i want to generate square wave from ac mains supply with 50 hz
ac input voltage after transformer will be 12 volts

What amplitude should the squarewave have?
What kind of load does it drive?
Do you already have a source of DC voltage to power the circuit?

 

[blowouter]

input ac 12 volts and output 5v square wave, it will be aclock for ttl ics

 

[JimB]

Try this circuit in the attachment.

The important thing is to use a gate or inverter such as a 7413 or 7414 which has a schmidt trigger input, otherwise you will get some strange effects such as bursts of high frequency oscillation in the output due to noise on the input signal.

JimB

 

[blowouter]

yes, this is really easy can i use 4093 or 40106 instead of 7413 and 7414
i tried using 4093 and it works on computer
i find a circuit using two diodes and but i can't really get it
View attachment 68404

 

[JimB]

can i use 4093 or 40106 instead of 7413 and 7414

Yes, no problem.
However, you did originally say TTL, the 4093 and 40106 are CMOS.

The circut you just posted works by clipping the AC, a bit like the zener in my circuit.
The problem is that what you get out is not a good square wave, the rise and fall times are those of the 50hz supply.
This can cause odd effects due to noise on the rising and falling edges. The schmidt circuit overcomes that problem.

JimB

 

[blowouter]

hello
first i say for ttl clock ics not by ttl , about the circuit i posted you are right it's kind of clipping ac using diodes and battery
the upper diode works and clip the ac to battery voltage , in the -ve the diode shorts and output nearly zero
i saw circuit that put capacitor at the input of the schmitt and a schmitt of course
thanks for helping