hsprao
Newbie level 2
Hi All,
I am triggering 3 relays one after other using microcontroller 89v51rd2. My application is like this
1. When I give input(5V) to microcontroller input1 then output1 becomes ON
2. Now I will get input (5V) to microcontroller input2 then output2 becomes ON
3. Now I will get input (5V) to microcontroller input3 then output3 becomes ON
all the microcontroller outputs are connected to T547(npn) transistor base through 4.7k ohm register and
+12V is connected to collector through relay and emitter is connected to ground.
Here In normal condition(without 230V connected to the relay) this is working fine. But when I connect a 230V(AC) load to the relay my microcontroller behaves wrongly. I mean when I give input(5V) to the microcontroller input1, immediately output1 and output2 triggers simultaneously irrespective of the input2.
So I have connected RC circuit to the 2.2K/1W resistor and capacitor across relay's AC network to avoid surge current. Still microcontroller triggers 2 relays simultaneously. Could you please suggest some solutions.
Thanks in advance.
I am triggering 3 relays one after other using microcontroller 89v51rd2. My application is like this
1. When I give input(5V) to microcontroller input1 then output1 becomes ON
2. Now I will get input (5V) to microcontroller input2 then output2 becomes ON
3. Now I will get input (5V) to microcontroller input3 then output3 becomes ON
all the microcontroller outputs are connected to T547(npn) transistor base through 4.7k ohm register and
+12V is connected to collector through relay and emitter is connected to ground.
Here In normal condition(without 230V connected to the relay) this is working fine. But when I connect a 230V(AC) load to the relay my microcontroller behaves wrongly. I mean when I give input(5V) to the microcontroller input1, immediately output1 and output2 triggers simultaneously irrespective of the input2.
So I have connected RC circuit to the 2.2K/1W resistor and capacitor across relay's AC network to avoid surge current. Still microcontroller triggers 2 relays simultaneously. Could you please suggest some solutions.
Thanks in advance.