PMDC driver circuit is not working

[amitkatheria91]

I have made a PMDC motor driver for Motor 24V20A. It is a bi-directional motor rotation circuit. It only rotating the motor in one direction, not in another direction. Please help me to fix it. PWM frequency is 50HZ. ‎एक और बात‎, it is working on the proteus simulation but not in the hardware. Please correct the circuit if any value or circuit is wrong.
See the circuit below.

 

[KlausST]

Hi,

you have two inputs: PWM and SD (sadly the same name as the SD inputs of the IR2104)
Can we see a truth table of the 3x NOR circuit?
How do you want the circuit to work (regarding PWM and SD)?
What´s the duty cycle range of the PWM?

Klaus

 

[FvM]

Do you understand that a bootstrap driver like IR2104 can't work with 100% duty cycle?

50 Hz PWM frequency doesn't sound reasonable. You want the frequency suffciently high to make the motor inductance smooth the current, at least several kHz. Also 1 µF boostrap capacitor might be too small for 50 Hz operation.

--- Updated Aug 31, 2021 ---

Can we see a truth table of the 3x NOR circuit?
How do you want the circuit to work (regarding PWM and SD)?

Looks reasonable. One half bridge is activating the low side permanently, the other switches between high and low according to duty cycle. SD is direction control.

 

[amitkatheria91]

Hi,

you have two inputs: PWM and SD (sadly the same name as the SD inputs of the IR2104)
Can we see a truth table of the 3x NOR circuit?
How do you want the circuit to work (regarding PWM and SD)?
What´s the duty cycle range of the PWM?

Klaus

Truth table according to the simulation is as .

 

[KlausST]

H,

a truth table does not work with volts and %.
They work with logic states like, HIGH, LOW, Z, X, true, false, 1, 0....

is these the
* expected function
* simulation result
* real circuit result

if you have a simulation, then show your simulation.

* IN1=2.5V and IN2=2.5V makes no sense. (assuming the 2.5V are the average of perfect 0.0V / 5.0V logic levels)
* 4.5V, 50% duty cycle makes no sense...

Klaus

 

[amitkatheria91]

H,

a truth table does not work with volts and %.
They work with logic states like, HIGH, LOW, Z, X, true, false, 1, 0....

is these the
* expected function
* simulation result
* real circuit result

if you have a simulation, then show your simulation.

* IN1=2.5V and IN2=2.5V makes no sense. (assuming the 2.5V are the average of perfect 0.0V / 5.0V logic levels)
* 4.5V, 50% duty cycle makes no sense...

Klaus

Hi, I am attaching simulation video

 

[KlausST]

Why do you say it´s not working?

Klaus

 

[amitkatheria91]

Why do you say it´s not working?

Klaus

It is working in simulation but not in real hardware circuit.

 

[KlausST]

Hi,

I did ask about it in post#5.

Now that the real part does not work, let´s focus on this.
* show us the schematic of the real circuit.
* show us some photos of the real circuit where can see all the wiring.
* if you have a scope: show us both half bridge outputs when circuit is not working as expected.

Please give all inofrmations at once, not piece by piece.

Klaus

 

[Easy peasy]

You say the hardware is not working - but you have supplied no detailed pictures of the hardware .... ?

 

[mtwieg]

First of all, kudos on showing a video of the simulation running. Nice way of showing exactly how you're running the sim and what you're observing.

Second, no the simulation is not really working properly. Your IR2104 circuits are supplied with 12V, and the bridge itself is supplied with 24V, so when a IR2104 input goes high, you should see ~24V on the output of its half bridge, and ~36V on the gate of the top FET. But instead you see just ~7V and ~12V, respectively. This is basically because the bootstrap capacitors are far too small for switching at 50Hz. Using 1000uF instead of 1uF might get things working better, but that's somewhat impractical for a real circuit. Better to operate at a much higher frequency (2-20kHz). And still bump up to bootstrap caps to ~10uF.

 

[FvM]

According to the video, the simulation is neither working correctly. No idea how you achieved it. The logic levels are not as expected for NOR gates.