hi >>>>>>
i am working in aproject of invertor and i have aproblem in transforming dc to ac ( from batrrey to output ) i use a555 isolator & invertor but i neet achip to make delay in the wave out of invertor to product asquare wave whats that chip ?

 

You say you already have a 555 - those are usually timer ICs.

555 timers can be used in astable mode (free-running oscillators) or monostable (timer) mode. You can connect them with a couple of resistors and capacitors to make square waves. They can output or sink up to 200mA of current.

 

Maybe he is making an inverter project with a center-tapped transformer and has two Mosfets driving it push-pull. The 555 drives one Mosfet and he wants a "delay" circuit to drive the other Mosfet with the opposite phase.
He should use a logic inverter IC or another 555 connected as an inverter.

I think a CD4047 IC is perfect for a simple square-wave inverter because it has an oscillator made with a single resistor and capacitor, a digital divider and two opposing outputs that are perfect square-waves. It even has its clock output at double the frequency that can be gated then makes a modified sine-wave waveform.

 

those two opposing outputs would have to have a little 'dead time' between them to avoid blowing up the supply.

 

If it were an H-bridge or a push-pull, the dead time would be a requirement. But is dead time actually needed for a center-tapped primary set-up?

 

Some Mosfets conduct a high current when each has a gate voltage of 6.5V when the square-wave is halfway through switching. But for only a moment if the drive has fast rise and fall times.

 

i would definately consider dead-time in a push pull converter. those devices take time to switch off and i would very much like to avoid cross conduction.