How to combine an LDR (Light Sensor Circuit) to an LED Driver using 555 Timer?

Can someone help me how do I do a circuit that has a blinking LED operated by 555 timer but only triggers when light is sensed. I know I have to use an LDR but how do I combine this with LED driver if it also uses 555 timer? Please reply as soon as possible. Thank you.

hi P,
What is the specification of the LDR, ie: light/dark resistance.?
Also the Blink rate required and LED type.

E

Blast Eric got there first!! Grr.

Ermmm welcome to the forum BTW

One way to do this is to first design the 555 oscillator and LED driver and get that going. Then add a small circuit that connects the LDR to the 555 Reset pin. If you are using a CMOS 555 (LMC555, etc.) it might be as simple as a resistor from Reset to Vcc and the LDR from Reset to GND. The 555 Reset input has a reputation for being a bit strange, but there is no harm in trying this simple way first; it may not work, but it will not damage the 555.

ak