Bidirectional mosfet switch as a current limiter

Thread Starter

vggrek

Joined Aug 5, 2018
10
Hello,
Can the bidirectional switch in the scheme work as a current limiter?
If yes, how am I suppose to choose the parameters of the components (mosfets, diodes).
Voltage source: 8-10kHz bidirectional square waveform, 40V peak to peak. (motor driver, input voltage 6V-27V, max current 43A)
Limit current value 7A.
 

Attachments

crutschow

Joined Mar 14, 2008
26,041
Does it have to use a bidirectional MOSFET switch, as putting the limit circuit inside a bridge would likely be simpler?
 
Last edited:

Thread Starter

vggrek

Joined Aug 5, 2018
10
Does it have to use a bidirectional MOSFET switch, as putting the limit circuit inside a bridge circuit would likely be simpler?
Maybe yes, I haven't the knowledge to design it and there are so much cheap motor drivers in the market.
The motor driver is this IBT-2. The motor driver has current sensing. My target is to prevent the shutdown on overcurrent, from the motor driver's mechanism, when a short circuit happens and have the time to handle the issue with an mcu. The 7A is defined as short circuit. If this solution works, I can also turn off the output to the load without have to shutdown the motor driver.
 

crutschow

Joined Mar 14, 2008
26,041
I can also turn off the output to the load without have to shutdown the motor driver.
The bridge approach could also do that.
Basically the limit circuit inside the bridge would be in series with the motor.

I haven't come up with a clean way to do it with the bidirectional MOSFET switch.
 

Thread Starter

vggrek

Joined Aug 5, 2018
10
Basically the limit circuit inside the bridge would be in series with the motor.
I'm confused. The bidirectional switch is in series with the motor. I can't figure out what limiting circuit and where in the bridge will be placed. Why the limiter you are talking can't be at the output of the motor driver? Could you please be more specific, point to a scheme or article?
I haven't come up with a clean way to do it with the bidirectional MOSFET switch.
What makes you doubt - worry about the functionality of the mosfet switch?
Thank you.
 

crutschow

Joined Mar 14, 2008
26,041
Why the limiter you are talking can't be at the output of the motor driver?
It can be.
The bridge limiter would be in series with the motor.
If that sounds okay to you, than I can try to gin up a circuit.
What makes you doubt - worry about the functionality of the mosfet switch?
I'm not.
I just haven't come up with an easy way to control it when it's carrying an AC current.
 
Top