dc motor drive(motor controller) using 12v 15a current

[suryaurza]

we design this circuit using 3 mosfet. this circuit gives short circuit current of 2A but we want that it gives short circuit current of about 15A.what's modification we want to do?

 

[suryaurza9]

12v 15a dc motor controller using pwm

we design 12v 3a dc motor controller using pwm circuit. which work properly and give the output 3a.
one irf 540 mosfet ,555timer , 500k pot, resistors, capacitors,4148 diodes
after then we modify the circuit and get 12v 15a dc motor controller using pwm circuit. so we 3mosfets in parallel and one 555 timer and other components same as use above circuit


but it does not provide short circuit current 15a
what will we do? tell us in detail plz


it give output current only 2a.

 

[(*steve*)]

What is your power supply?

That circuit doesn't limit short circuit current, so I'd be *VERY* careful shorting out the load.

Also... R4 seems to be in the wrong place. The resistors should each be connected to a single gate and then connected together before connecting to the output of the 555

 

[(*steve*)]

Also, is there any reason you're posing the same question multiple times?

It won't get you better or faster answers, but it will annoy people.

edit: Not only multiple posts, but multiple users. Decide which one you want to use and stick to it!

edit2: THREE posts!

 

[suryaurza]

we use 12v dc power supply.can you help to simplify this circuit?

 

[(*steve*)]

You response tells me nothing.

I will assume that you have some form of protection to ensure nothing fails.

1) Fix R4

2) Try again

3) Tell me what happens (there is a possibility one of your mosfets is damaged)

 

[suryaurza]

we fix R4 but it does not provide short circuit current 15A. i think 555 timer output does not suitable for 3 mosfet can we amplify this output.

 

[(*steve*)]

OK, I will assume that nothing changes.

The next step is:

1) short out C1

2) try again

3) what current do you see?

If the current is still low measure some voltages for me. ALL of these should be with respect to the ground (-ve) supply DIRECTLY on your power supply.

a) pin 1 of the 555
b) pin 8 of the 555
c) pin 3 of the 555
d) gate of Q1
e) gate of Q2
f) gate of Q3
g) source of Q1
h) source of Q2
i) source of Q3
j) drain of Q1
k) drain of Q2
l) drain of Q3
m) junction of D3 and D4
n) +ve supply at power supply.

I expect 1 current reading, or 1 current reading and 15 voltage readings. If there is a lot of heating, you may want to connect the multimeter and then turn the circuit on briefly to take each measurement.