Motor Controller with Flyback Voltage protector

260

04:11:05

In this circuit there is a Logic signal that is going to turn on and off the BJT (NPN) I assume 5V as logic value, the resistor of 1KΩ on the base of the BJT is a good value to limit the current to the base of the transistor since we need 0.7V VBE to turn on the transistor, in this case the resistor need to drop 4.3V, and we are going to have about 4mA passing through the resistor. When the transistor is switched on, all the current flows from the motor to the collector terminal and pass through the transistor, The Diode in parallel with the motor has the function to drop the flyback voltage emitted by the motor until it stops.

published 5 years ago

Tedski

5 years ago

It's a nice change to have a circuit with a good explanation of its workings..!!!

Pessanha2

5 years ago

I will explain better, as soon as i start to improve my English. Thank you very much

Tedski

5 years ago

Your English is better than mine and I'm English!!!

Pessanha2

5 years ago

I am not but, english people are always very polite. Thank you very much for you kindness :)

BillyT

5 years ago

To see the motor turning set the display time to real time, (1 sec). If the voltage across the motor in going to be less than 6V, set the motor voltage to say 5.5V. If you are applying 4mA to the base of a transistor with a gain of 100, try setting the motor starting current to 400mA.

Pessanha2

5 years ago

Thank you for the tips. Done

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