I have one sensor that goes on/off at times, I want to flash 2 LED strings (RED, GREEN) every 1 second using a 555 IC.
So when sensor ON
1st second GREEN-ON,RED-OFF
2nd second GREEN-OFF, RED-ON
the 555 IC can sink and source, do I use a P and N channel MOSFETs to drive the LEDS?
Is this schematic correct? have I connected the MOSFETS correctly and also I'm not sure about the 555 timing if it is 1 second ON 1 second OFF
Can anyone suggest different approach
Please help
Best Answer
You can drive the strings like this (555 circuit shown for 50% duty cycle when used with CMOS 555) M1 needs to be a logic-level MOSFET. For 1Hz (0.5s on 0.5s off, R6*C1 needs to be about 0.71, so you could use 1uF and 710K with a CMOS 555.
simulate this circuit – Schematic created using CircuitLab