Led Flashing Speedup

Thread Starter


Joined Dec 7, 2011
Hi there, I had a LED flashing circuit here and the LED blinking quite slow for me and I am thinking to make it blink a little bit faster.

Here is the circuit:

Please guide me. Thanks in advance.


Joined Apr 16, 2010
As t06afre posted, you can use the datasheet to find the formulas for calculating the duty cycle and flash rates. It's actually not too hard, but in the meanwhile, here is a table that shows some options. The top row shows what you have now, which should produce a flash rate of .07 Hz (on and off once in about 14.3 seconds.)

You can speed it up by decreasing C1; as shown in the table, changing C1 from 100 μF to 10 μF increases the flash rate to .72 Hz, (on and off once in about 1.43 seconds.)

Another way to increase the flash rate is to lower R2; see the table for some examples. In fact, you can play around with the values of R1, R2, and C1 to see the results in duty cycle and flash rate. R1 can't go a lot lower than 1000 Ω, or it begins to get too hot.