if you need to reverse the motor or switch it but not control the speed relays are fine, you only use PWM to adjust the average power output using duty cycle. 50% duty means half the time it's off and half it's on, by doing this as a high enough freqency the switching is transparent and the load averages it out.
when building a high-current motor controller with PWM don't use the IRF510 (mosfet from radioshack), they generate way too much heat. ST sent us a lot of samples and after evaluating the MESH Overlay Power III mosfet like stp75ns04z (80amp), you wouldnt believe the difference, virtually no heat at 4amps+. little energy wasted in switching even at 3.8+KHz. The Power III mosfets designed for power tools, etc and is even internally clamped for protection. don't even need a flyback diode.
I'm doing the motor control with PWM input to PIC, from flight Simulator.
For example, less than 1ms will move the motor to the left, 1 ms will be the stop position and more than 1ms will move the motor to the right. Let say, PWM is now 1.5 ms and if it changes to 1.3ms, i have to reverse the motor direction too.
Do you have any idea about it and may i request you to give me some ideas in programming part too :D?
PLS reply asap, it's very impt to me, it's my sch project. :D thanks
I understand, and your right about switching direction the motor have to stop before you change direction or you will burn up the mosfets. This is my controllers design, 120v 500 amp water cooled speed controller.
Hi. I agreed with you the relay with 2PDT will do the job. But the relay is mechanical solution and you will have either forward or reverse direction only. Your motor will give way easily if you switch the direction at high speed. No speed control can be achieve as well. My circuit is more flexible in the sense that i can control the direction and speed by PWM which is more efficient. Thanks.
how did you did what have you used to make it what parts are those? can you please tell me the instructions how will is suppose to learn all this i started electronics now. plz reply
I have a setup like that running now for a class project, and my FET's haven't even gotten warm. One thing to watch out for though (if you decide to mess around and switch direction quickly) is that FET's like to burn out if you don't have all four flywheel diodes.
What did you use to control direction? I used a quad NAND and some buffer FET's, and just had Direction and Enable pins from the MCU. Probably would've been better to use opto-isolators & implement something more sophisticated...
Hi there. In fact the direction is control by PIC MCU. The microcontroller uses ADC to detect the variable resistor position and out put the value respectively. You need to download the hex code in order for the PIC microcontroller to operate.
Ah I see, you're running the motor at 5V and switching the transistors directly (my motor is at 12V). One thing to watch out for, if you're careless and switch direction quickly (if you're using MOSFET's), they can burn out and lots of current will flow through the gate into your PIC and destroy it.
I re-implemented my H-bridge using opto-isolators... I got tired of my buffer MOSFET's burning out.
I am using PIC assemble language to compile the program. Good luck. Cheers.
SAGUTRIC 2 weeks ago
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what's the PWM frequency?
APIb0000 2 months ago
if you need to reverse the motor or switch it but not control the speed relays are fine, you only use PWM to adjust the average power output using duty cycle. 50% duty means half the time it's off and half it's on, by doing this as a high enough freqency the switching is transparent and the load averages it out.
FJSchrank 2 months ago
7-11 mOhm RDS-on for the STP75NS04Z
FJSchrank 4 months ago
when building a high-current motor controller with PWM don't use the IRF510 (mosfet from radioshack), they generate way too much heat. ST sent us a lot of samples and after evaluating the MESH Overlay Power III mosfet like stp75ns04z (80amp), you wouldnt believe the difference, virtually no heat at 4amps+. little energy wasted in switching even at 3.8+KHz. The Power III mosfets designed for power tools, etc and is even internally clamped for protection. don't even need a flyback diode.
FJSchrank 4 months ago
I'm doing the motor control with PWM input to PIC, from flight Simulator.
For example, less than 1ms will move the motor to the left, 1 ms will be the stop position and more than 1ms will move the motor to the right. Let say, PWM is now 1.5 ms and if it changes to 1.3ms, i have to reverse the motor direction too.
Do you have any idea about it and may i request you to give me some ideas in programming part too :D?
PLS reply asap, it's very impt to me, it's my sch project. :D thanks
LeoDheLion 6 months ago
whats the PWM frequentie?
eTh0maz 1 year ago
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You can buy PWM LED dimmers and controllers at Digital lighting systems, miami fl , USA
REVIEW420 1 year ago
where did the motor come out of?
simulation17 2 years ago
cute little motor, what did you use for the speed control?
MacsCanfly 2 years ago
What pic processor is that?
and did you use assembler?
Could you please send me the schematic :D
jacool1994 2 years ago
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this is bob. copy and past him every where. he will soon rule youtube.!!!
Approx00zero 2 years ago
I understand, and your right about switching direction the motor have to stop before you change direction or you will burn up the mosfets. This is my controllers design, 120v 500 amp water cooled speed controller.
TommeyLeeReed 3 years ago
the h-bridge is ok,but too many mosfet needed.
use a relay its cheaper and works very well.
TommeyLeeReed 3 years ago
Hi. I agreed with you the relay with 2PDT will do the job. But the relay is mechanical solution and you will have either forward or reverse direction only. Your motor will give way easily if you switch the direction at high speed. No speed control can be achieve as well. My circuit is more flexible in the sense that i can control the direction and speed by PWM which is more efficient. Thanks.
SAGUTRIC 3 years ago
you can use a relay for switching the direction and a mosfet to sink the current given to the relay there having a cheaper solution that also has pwm
ldom2244 3 years ago
OK. You also have the point. Cheers.
SAGUTRIC 3 years ago
how did you did what have you used to make it what parts are those? can you please tell me the instructions how will is suppose to learn all this i started electronics now. plz reply
chemistrycoolguyscom 3 years ago
Hi. I would recommend you read "123 PIC Microcontroller Experiments For The Evil Genius By Myke Predko" Cheers
SAGUTRIC 3 years ago
Very nice!
Full bridge?
Better add heat-sinks over those FETs (?)
Ran
noamkiller 4 years ago
I have a setup like that running now for a class project, and my FET's haven't even gotten warm. One thing to watch out for though (if you decide to mess around and switch direction quickly) is that FET's like to burn out if you don't have all four flywheel diodes.
What did you use to control direction? I used a quad NAND and some buffer FET's, and just had Direction and Enable pins from the MCU. Probably would've been better to use opto-isolators & implement something more sophisticated...
uniment 4 years ago
Hi there. In fact the direction is control by PIC MCU. The microcontroller uses ADC to detect the variable resistor position and out put the value respectively. You need to download the hex code in order for the PIC microcontroller to operate.
SAGUTRIC 3 years ago
Ah I see, you're running the motor at 5V and switching the transistors directly (my motor is at 12V). One thing to watch out for, if you're careless and switch direction quickly (if you're using MOSFET's), they can burn out and lots of current will flow through the gate into your PIC and destroy it.
I re-implemented my H-bridge using opto-isolators... I got tired of my buffer MOSFET's burning out.
uniment 3 years ago
very nice!
Full bridge?
better add heatsinks over those FETs (?) =]
Ran.
noamkiller 4 years ago
thx
belamirdz 4 years ago