Using the same power supply for motors and microcontrollers

Other Hardware Motors, Mechanics, Power and CNC
1

Hello everyone,

I want to use +12V battery(two +6V, 5Ah batteries in series) to the power some motors DC motors as well as a 8051 microcontroller and an Arduino Uno simultaneously. I'll use LM7805 Voltage regulator to bring down the voltage to +5V for the Uno and the 8051. I've learnt from somewhere that the motor may cause noise in the circuit and this in turn will reset the microcontroller. If I use capacitors and diodes before the Input of the 7805, will it help my cause? What should be the necessary filter circuits for this to work? Will an optocoupler act as filter if I use it before the input of LM7805?

P.S: I am trying to design a PCB for my project. The DC motors will be controlled with the L293D.

Thanks :slight_smile:

2

A capacitor diode combination will allow the regulator to keep running for a limited period if the
supply voltage dips, not a bad choice. Larger cap or smaller load current means longer endurance.

3

MarkT:
A capacitor diode combination will allow the regulator to keep running for a limited period if the
supply voltage dips, not a bad choice. Larger cap or smaller load current means longer endurance.

@MarkT:

Will Schottky diode be a good choice instead of a regular diode? and you're saying 'large Cap' so exactly how much will do? Within 10-100uF or more than 100uF?