Hello ,

I'm making a circuit to drive a 160V , 15A DC motor .

how can I protect the elements of the circuit from over current or abusive usage , can fuses or circuit breakers work in protecting electronic elements from over current or would it be too slow for electronics .

also what is the difference between a normal circuit breaker and a motor overload protection , why is the motor overload protection much more expensive.

also , Is there something specific for DC .

If there is a certain book or reference related to this , please , tell me about it .

 

Hello ,

I'm making a circuit to drive a 160V , 15A DC motor .

how can I protect the elements of the circuit from over current or abusive usage , can fuses or circuit breakers work in protecting electronic elements from over current or would it be too slow for electronics .

Hi, you are back! Did the MOSFET burn again???

What do you want to protect? MOSFET or MOTOR?

MOSFET:
Overvoltage: put a snubber on it, for example an RCD clamp
Overcurrent: best is to use an electronic overcurrent protection like the pulse by pulse limitation used in PWM current mode controllers

Fuses most likely and definitely circuit breakers are too slow to protect a MOSFET from overcurrent.

A fuse will however will provide some protection if you overload the motor for example.

 

Hi, you are back! Did the MOSFET burn again???

:] , No it didn't , I want to make sure it will not .

 

I also see some boards with an earthing pin connected to the metal case of the device , what 's that pin electrically connected to?

 

I also see some boards with an earthing pin connected to the metal case of the device , what 's that pin electrically connected to?

Depends on the device. Could be part of a filter for example.
http://www.exergia.info/Lightning/lightning7.htm

 

what about motor overload protection elements , I've seen one today , but its for AC motors , I asked if there is one for dc motors , but I couldn't find one , I know that it depends on measuring the temperature caused by the flowing current to determine when to open the circuit , so , it won't be the same for both Ac and Dc .

so , Is there something else available for DC motors .

If not , Is there a certain relation between its rated current in AC and the DC current it would permit.