The TLC555CP timers I bought from Mouser don't look like the data sheet: There is no notch in the 8-pin PDIP to indicate which end pin 1 is at.
Instead, there is spot/indent in the top of the package near pin 2 ?
So I assumed that was the pin one end and put them in the board that way round, but they're not working.
With VCC=12v I have 10k from Vcc to pins2+6 (trig+thresh) and 5.1k to DISCH. There is 4v on pins 2+6 (the 5.1 and 10k pot-down) and 0 on DISCH,
i.e. it is pulled down.
I believe it should not be pulled down if the voltage on pins 2+6 < 2VCC/3 = 8v. There is 8v on pin 5 and Vcc=12v on pin 4 (reset).
Just tried putting it in backwards and it's exactly the same. I'v e tried replacing the device but all do the same.
Please confirm which end is pin 1.
