Hi,
Although I am a novice I can normally troubleshoot stuff OK but this is driving me mad.
The following circuit portion is supposed to do 2 things when it gets a low signal on Q1 , sound a buzzer for 5 seconds before switching on the relay. Q1 turns on the 556, Timer1 goes low for 5 seconds and then high, while Timer2 goes high for 5 seconds and then low. Yes I know there are probably better ways to do it and I am going to redesign this part, I can't remember the reason I used 2 timers now, as it was designed a while back, but I would like to know why this doesn't work properly...
The problem is that the circuit seems to work fine on the breadboard, but in the actual circuit the buzzer part just stays high. If I connect my multimeter up to the output of Timer 2, it shows 5v for 5 seconds and then 0v, as if it's working correctly. Why is it when I connect a load that it locks the output high?
TIA
Les
Although I am a novice I can normally troubleshoot stuff OK but this is driving me mad.
The following circuit portion is supposed to do 2 things when it gets a low signal on Q1 , sound a buzzer for 5 seconds before switching on the relay. Q1 turns on the 556, Timer1 goes low for 5 seconds and then high, while Timer2 goes high for 5 seconds and then low. Yes I know there are probably better ways to do it and I am going to redesign this part, I can't remember the reason I used 2 timers now, as it was designed a while back, but I would like to know why this doesn't work properly...
The problem is that the circuit seems to work fine on the breadboard, but in the actual circuit the buzzer part just stays high. If I connect my multimeter up to the output of Timer 2, it shows 5v for 5 seconds and then 0v, as if it's working correctly. Why is it when I connect a load that it locks the output high?
TIA
Les