I'm working on my first little circuit and could really use some help working out the specs of the components. As you can see on the photo below, I'm trying to have two LEDs light up, and when switched to the secondary circuit, to make them flash (preferably 2-3 times per second). I'm using two 10mm white LEDs with a forward voltage of 3.2V-3.8V each. To make them flash, I want to use a relay (JQC-3F) and a capacitor. I found that circuit on google, but it was different (1x3mm LED), which is why the specs for the components are different now. Any help would be greatly appreciated and if you have a better solution, I'd be very interested!

 

Experiment with a range of R1 from 220Ω to 1000Ω to see how much brightness you desire.

As for the flashing LEDs, scrap the mechanical relay and use a 555-timer circuit.

 

Experiment with a range of R1 from 220Ω to 1000Ω to see how much brightness you desire.

As for the flashing LEDs, scrap the mechanical relay and use a 555-timer circuit.

Thank you for the quick reply! I'll try them out.
I kind of like the mechanical relay (clicking sound). Is there a way to keep it?

 

Thank you for the quick reply! I'll try them out.
I kind of like the mechanical relay (clicking sound). Is there a way to keep it?

If you like the clicking sound, use the 555-timer to drive the relay.

 

If you like the clicking sound, use the 555-timer to drive the relay.

Ok, thanks! Now I just need to read up on how 555-timers work and how I'll integrate it in my circuit.

 

Here it is, the 555-timer tutorial from the late Tony van Roon.

http://www.tonyvanroon.com/oldwebsite/gadgets/555/555.html