8051 based relay control.

Thread Starter

tepu

Joined Feb 11, 2015
1
Dear All
I want to controll relay of 5vdc from microcontroller 89c52.I want to know that i have to connect signal pin to relay circuit directly or it requre pull ups in betwen controller & relay circuit?
 

absf

Joined Dec 29, 2010
1,942
If only one relay use a NPN transistor to drive relay. If more than one then use ULN2003 darlington drivers.

If using Port 0, pullup resistor is required. P 1,2,3 got internal pullups.

Allen
 
Top