Hi everyone,

Could someone please suggest me a simple way to invert a PWM signal.

I have a 0-5 V PWM signal with 50 % duty cycle generated from a 1- channel pulse train output terminal.

I would like to invert this signal in-order to feed my H-bridge circuit.
I thought of using a NOT gate IC 7404.

Is that the right way or is there a better solution.?

Thank you!!

 

A transistor would be simpler:
http://electronicsclub.info/transistorcircuits.htm
I think the NOT gate IC is just a number of these,
and you only need one.

 

A transistor would be simpler:
http://electronicsclub.info/transistorcircuits.htm
I think the NOT gate IC is just a number of these,
and you only need one.

Please see the attachment..
is that sufficient?

 

Art has provided a link to a single transistor inverter. The hex inverter you linked to is surface mount and has five more gates than you need, but yes, it would work.

 

Why do you want to invert a PMW signal with 50% duty cycle?
You will end up with 50% duty cycle.

Edit: Sorry, I just read you want to drive an H-bridge.

Use another port pin or use a single transistor.

Note that you will end up with phase delays.

Use a toggle flip-flop to avoid phase shifts. Or use an mcu that generates complementary PMW with controlled delays.

 

Why do you want to invert a PMW signal with 50% duty cycle?
You will end up with 50% duty cycle.

Edit: Sorry, I just read you want to drive an H-bridge.

Use another port pin or use a single transistor.

Please see my attachment( To obtain a signal similar to that ) and drive a H bridge circuit.
sorry , I wasn t specific.

 

Use a toggle flip-flop to avoid phase shifts. Or use an mcu that generates complementary PMW with controlled delays.

Thank you Mr.chips for the suggestion.
My first choice was to use a J-K flip flop in toggle mode .
But I couldn t understand the IC's functionality properly. So, I ended up with this Inverter IC.

could you please provide me with some information about toggle mode operation of J-K flip flop ?

 

To make a toggle flip-flop from a J-K flip-flop, connect both J and K inputs high.
The output frequency will be half the input clock frequency.

 

To make a toggle flip-flop from a J-K flip-flop, connect both J and K inputs high.
The output frequency will be half the input clock frequency.

Thank you for the response.
If I understood right ,
Please check my attachment where I just took an example and tried to figure the concept you mentioned.

 

That is correct.

You should also connect pins 2 and 3 to high to prevent spurious noise from messing up the flip-flop.

Also connect pin-6, 2CLK to ground to disable the second flip-flop.

 

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Use another port pin or use a single transistor.

Note that you will end up with phase delays.

................

The small phase-delay to the PWM digital signal from the propagation delay of an inverter is not likely to be a problem in most PWM applications since the PWM carrier frequency is normally much higher than the modulation frequency.