There are probably Mosfet driver ICs available

OK, please tell name of it i don't want to make it complex using discrete part...

 

RRitesh, these threads are so long and you don't get the information you need because you don't provide the necessary informations to us.

Before starting such a project you have to have an idea about the PWM frequency you want to use.

Then we need to know what your location is, or where do you get your parts from, what is your local distributor? If "Earth" is your location then you will be able to get any part you need.

I will give you an example:

"I have IRF540 and IRF9540 transistors available. I want to use them in a H-bridge configuration to drive a DC- motor at a PWM frequency of 12kHz.
I will be using a PIC and I have 2 output ports available.
The motor is a 24V, 100W brushed DC motor. I can / cannot get any exotic gate drivers because I live in ..... Please suggest a circuit."

The "test" circuit you posted (the 12V circuit) does not provide any protection against shot-trhough,i.e it does not make sure that only the upper or only the lower MOSFET is turned ON. This has to be made with a resistor/diode combination and /or schmitt-trigger gates and an RC combination or directly in the PIC.

 

Rritesh said somewhere (maybe on another website's forum) that he is a 20 years old university student in India.
His English is getting better but his English spelling is still bad (briges).

 

Good spelling isn't a must in AAC. Will to pass information along and cooperate is.

 

Good spelling isn't a must in AAC.

When their spelling is RONG then it is difficult for us to translate what they are talking about. Maybe they should talk in their own language on a website in their own country.

You are in Greece where I also chat on an English(?) electronics forum www.electronics-lab.com . Many of the projects were translated from Greek and do not make sense in English.

 

So what gives? Should we ask a or IELTS degree along with their e-mail when a user subscribes on AAC?

We make do with what we have.

 

I think that the student kids in India should ask their teacher to teach them about the basics of electronics.

 

"I have IRF540 and IRF9540 transistors available. I want to use them in a H-bridge configuration to drive a DC- motor at a PWM frequency of 12kHz.
I will be using a PIC and I have 2 output ports available.
The motor is a 24V, 100W brushed DC motor. I can / cannot get any exotic gate drivers because I live in ..... Please suggest a circuit."

The problem is that i have never done speed control of DC motor before, so i guess after this project i will able to know all necessary information collection while designing a H-BRIDGES with PWM.

So, now also i am not sure which freq will be suited for controlling motor.

The motor is a 24V, 100W brushed DC motor.

The motor which i am using is brushed DC gear motor 6-24V stall current 5Amps no-load 300mA.

The "test" circuit you posted (the 12V circuit) does not provide any protection against shot-through,i.e it does not make sure that only the upper or only the lower MOSFET is turned ON. This has to be made with a resistor/diode combination and /or sch mitt-trigger gates and an RC combination or directly in the PIC.

It was for testing purpose only...So now you please provide a schematic with possible protection of motor and power source.

 

The motor which i am using is brushed DC gear motor 6-24V stall current 5Amps no-load 300mA.

Unless for some reason you NEED to use the IRF9540 you could do it with 4 IRF540 too. As a driver you could use 2 IR2110 chips. They are very common and here at AAC there are also a lot of threads talking about them.

Do you mind having a look through these threads? Common problems have been described numerous times.

Click on "search" and type as keyword "2110". I found 17 threads.
Have a read , draw a schematic of what you think your circuit should look like and then post it here.
For 24V/5A there shouldn't be any problems.

 

Hi,

I am planning to use both IRF 540/9540....
What do you think which will be better to use all N or both P and N MOS??

 

Will this schematic will work fine.......?
and what should best PWM freq ...??

 

Will this schematic will work fine.......?
and what should best PWM freq ...??

The LM339 is a simple comparator. The gates will be charged/discharged through the output transistor of the LM339 and the pullup resistor. For PWM you will need something faster, i.e. something that can charge and discharge the gates faster.

Have a look at the internal diagram of this gate driver. See? there are two transistors at the output, one that goes to the + rail, one that goes to ground.

Your driver can be made completely out of transistors too, even for fast PWM, but it gets a little more complex.

 

The LM339 is a simple comparator. The gates will be charged/discharged through the output transistor of the LM339 and the pullup resistor. For PWM you will need something faster, i.e. something that can charge and discharge the gates faster.

Have a look at the internal diagram of this gate driver. See? there are two transistors at the output, one that goes to the + rail, one that goes to ground.

Due you think this will work fine......??

Your driver can be made completely out of transistors too, even for fast PWM, but it gets a little more complex.

 

Due you think this will work fine......??

Depends on the frequency. Which you did not yet determine.

What's the 1nF capacitor for? You could put a diode from gate to 24V to discharge the gate of the PMOS faster.

 

Due you think this will work fine......??

It users a very old and very slow LM339 which is slow because it is old and is low power. Its output current is only 6mA.
You need a Mosfet driver circuit or IC that has an output current of hundreds of mA to quickly charge and discharge the high gate-source capacitance of the Mosfet so it can switch on and off quickly so it does not slowly ramp which would make it get hot.

It seems that all your parts are very old.

You did not reduce the 24V gate-source voltage so the P-channel Mosfet will probably blow up!

 

The circuit is working fine....
One problem is there i.e. when i stop the motor it does start quickly as it was working with direct power source and some noise is also cumming from motor ...and i am not using Capacitor as shown in upper side of P- MOS!!

 

The circuit is working fine....
One problem is there i.e. when i stop the motor it does start quickly as it was working with direct power source and some noise is also cumming from motor ...and i am not using Capacitor as shown in upper side of P- MOS!!

RRITESH,

At what frequency are you switching the transistors?

 

when i stop the motor it does start quickly as it was working with direct power source

No details so I don't know what you are talking about.

If you start a motor with PWM set at wide pulses for full speed then the motor receives almost exactly the same amount of power as a direct DC source.

 

15 seconds ago the frequency was reported on the other website.

 

15 seconds ago the frequency was reported on the other website.

What other website?

I'm not active in other forums.