Simulated Lighthouse Light

I am currently trying to put a slow flashing light in the top of a small wodden light house. I am having trouble deciding on how I want to control the light. I origanally was going to use a simple triangle wave oscillator feeding a small amplifier but I am having a hard time getting the circuit to oscilate at less then 10Hz.

The bulb that is being driven is a 3V flashlight bulb. The oscillator was made up of two opamps but I don't think that it will oscilate at a low frequency. The supply voltage will be 3 to 6 volts depending on power usage.

The desired effect is to have the light slowly fade on and off to simulate the light in an actual light house. I guess the frequency would be about one cycle per 5 seconds or so.

If anyone has some ideas on how I can make a low frequency oscillator or if you have any other methods for driving the light I would be very thankful.

Try using a 555 osc/timer IC as the input driver to the amp. You can get a slowly ramping voltage from a 555 timer by tapping off the timing capacitor at pins 2 & 6 ( astable mode). You can leave pin 3 un-used or just connect it to an LED as a monitor.