Re: power on delay using a 555 chip

Chris, I did try out the circuit but went about the testing in a phased
manner.
Step 1:
I rigged up the 555 in astable mode. Provided it with supply from a 9V
battery. Checked the output pin for oscillation and found it to be ok.
Step 2:
Then I rigged up a simple DC supply circuit using a 5.2V zener in
parallel with a 470uF/16V capacitor. (This circuit is explained in the
application note 954A of microchip corporation). Using this as the
primary source of the power to the 555 i checked the output pin for
oscillations and found it to be ok.
Step 3:
Rigged up a circuit containing of a 40W GLS lamp in series with triac
BT06600 from ST Micro. Connected one end of the lamp to the MT2
terminal. Other end of the lamp was connected to Phase (240Volts AC
RMS). MT1 terminal was connected to Neutral. Connected a wire from gate
terminal but did not connect it to the output of the 555 as yet.
Step 4:
Switched on the power supply and checked the output at pin 3 of 555 and
found it to be ok. As the gate terminal was not connected the lamp did
not glow. Now when i connected the gate terminal to the output of the
timer the 555 went kaboom. So did the triac. Unable to understand what
went wrong. Any help would be appreciated.

.

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