beginner differential drive circuit

Hello all,
I’m definitely a beginner and I’m having trouble with a really simple line following circuit using the differential drive method. I’ve attached a copy of the basic schematic for one motor.

  • I’m using PWM from an Arduino Uno (Logic Control)
  • The Rb value is 220 Ohms
  • Using an N-channel mosfet IRF530
  • 12 Volt lead acid battery (rechargeable)
  • 12 V DC brushed motor (Jameco 161382)

There is an issue with the mosfet that I don’t understand. It actually worked for a little while but then quit. Either the mosfets burned up or they are not receiving adequate voltages. It’s done that twice now. Is there an easy way to test them? I am probably missing something in the datasheets that I don’t understand. These mosfets were free so that’s why I’m using them. What would be the ideal type of transistor/mosfet for this application? Is there something with the switching times of the PWM from the Arduino in relation to the mosfet that I am not getting? I read somewhere that slow switching times can burn up a mosfet.

Thank you so much for your time.

Motorcontrol-1.doc (29.5 KB)

The MOSFET you have is not a "logic-level" MOSFET. That is, it won't turn on (fully) with only 5V at its gate. Logic-level MOSFET's are ones like the NDP6060L that will turn on strongly at 5V.

Otherwise everything looks appropriate. Maybe give us a sense for the current draw of your motor (if known) to further diagnose the problem.

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