Thank you for your response sir…
As you said,I am using a 12V common power supply.By using a 7805 regulator,it is cut down to 5V and is supplied to PIC board section and IC supply voltage .
For 12V pin (Vs) in L293D,It is taken in parallel from 12V dc power in the board and there is no connection with PIC section.then how this will happen??
Also Is capacitances necessary??
Rgds,
George