Normally On Blinking Light Bulb From 555 Timer Circuit

Hi all,

I’m designing a circuit that will use a 555 timer to blink a light bulb. However, the bulb needs to be normally on and will blink only after the timer starts oscillating. The light bulb load will be 12VDC at ~5A.

Attached is a schematic of a circuit that I built using a N-channel enhancement mode MOSFET. The design works great with an LED. However, once I replace the LED with an incandescent light, the bulb stays dark. Does anybody have suggested changes to this circuit that will make a bulb like an automotive taillight blink?

Thanks for your help!

Where did you put the globe?

Where the LED is shown.

It must go in place of the resistor.

Thanks for the suggestion. The globe now blinks, but it is normally off. I need it to be normally on.

Try the first circuit. Obviously use the correct value components.

**broken link removed**

Will do...does the globe stay, as you previously suggested, on the drain side of the MOSFET?

The globe stays the same