EM brake control using micro

[Electro nS]

i want to open close an EM brake .

details : EM brake continous current 0.5A , i donot know the peak but the spark is high when it is disconneted

i am using a pic and transistor with flyback diode across the inductive load (brake) , the operation is not perfect and i am not happy with the results maybe because the pic is not able to supply the required base current (around 20mA-50mA) very well ... donot know ?

i have check some similar systems , they use a relay , but why ? is it better ? what if i decided to use relay instead of transistor (although i will have to use a small transistor to drive the relay) , does it cause problems in the PCB ? noise , arcing ?!!! suggestions ?

 

[tpetar]

Usually transistor/MOSfet drive relay coil, and over relay coil is used flyback diode.

Generaly its not smart to driver relay coil direct with uC pins.

You should read uC datasheet about maximum allowed current per pin, total current,...