In search of a variable rate strobe circuit

[Glorfindel]

Before I go out and purchase all the components to make one myself, like the one from All Electronics ( which isn't variable) does anybody know of a single chip that lights up only 1 white LED with a variable rate pot? Years ago I had seen one but have long forgotten the LED shop that sold it.
Thanks boys.

[EVApodman]

Do you want to vary the rate of flashing with an external control? That can be done with a simple 555 chip and rheostat in place of the timing resistor.

Get a rheostat in the value range of the rate you want to flash at.

[MillenniumFalsehood]

Definitely the 555 timer is a great, simple little device to get a strobe to flash. Just remember to hook up a diode across the timing resistor, like in this diagram:



If you don't, it won't be a strobe because the duty cycle (i.e. the amount of time the light is on) won't be able to get less than 50% of the frequency, making it more like a position marker than a strobe.

[TAC]

Have not tested this, but cannot see why it would not work.
I would use, in my first test, a 10 nF capacitor on pin 5. A 10 uF capacitor (to start with) on pin 6. The fixed resistors in option three could be about 1K each. The trim pots could be 10 K each. If test flash rate is unsatisfactory, I would change the 10 uF value first.