rudolph.vermaak
New Member
I have got a problem. I designed a circuit which controls up and down movement of lights. I'm using remote digital receivers which supplies a trigger pulse of 1 seconds to a 74121 IC. It inturns provides a 0.5 second pulse (One shot). The pulse from the IC is fed to a transitor CBC182 this inturn switches a pair of relay's that have 220VAC on the NO contact. I designed three circuits that are exactly the same. All these circuits have two channels (UP and DOWN) to each channel a relay is connected. I have on each circuit a +5VDC regulater this is the only physical connection between these three circuits. These regulators are connected to a 12VDC rail. Now the problem is when I connect the 220V to the relay's and operate the one circuit the other two circuits get some sort of interferance on them and they switch the relay's without receiving a pulse from the digital receiver. So the other lights move at random. I have already grounded the unused inputs to all of the IC's. Now what can I do to stop this interferance from the 220V onto the other channels??????????? :evil: