I am working on a new project which requires an LED light to turn ON for 8 seconds and turn off automatically after 8 seconds. This is for a seat belt minder. During those 8 seconds, flashing LED every 0.5s would also be nice to have, but optional per the safety standard. So I tried making a circuit using the NE555 as attached to generate a single shot 8s timer. The model I have should theoretically produce 8s ON (no LED blinking) but the output waveforms don’t represent that. Something is wrong in the circuit. Any suggestions on why i'm not seeing an output that stays ON for 8s as soon as powered and then should turn off itself even though the power to the IC remains. Right now, the output stays LOW the whole time.
I understand that i have to use 556 dual timer if i wanted to do the LED blinking functionality as well. but for now, i just want to troubleshoot this one shot 8s timer using NE555 hopefully.
*** update:having the power supply VG1 turn ON faster (0.01 s rise time) made my output turn ON for 8s and turn off properly, thanks to AlbertHall)***
I understand that i have to use 556 dual timer if i wanted to do the LED blinking functionality as well. but for now, i just want to troubleshoot this one shot 8s timer using NE555 hopefully.
*** update:having the power supply VG1 turn ON faster (0.01 s rise time) made my output turn ON for 8s and turn off properly, thanks to AlbertHall)***
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