Flashing 3 pin LED

Thread Starter

SanctuCaryCustoms

Joined Jul 4, 2019
6
Hello everyone,
First time posting.
I was trying to work out how to get a 3 pin 2 colour led to flash between the 2 colours at about 1Hz. Have found diagrams to do it using 2 different leds but these need 2 separate leds to work as they don’t share a cathode or anode. Also want to run it on 12volts.
Any help will be grateful.
 

dl324

Joined Mar 30, 2015
9,111
Welcome to AAC!

Draw a picture of the waveforms you want so we don't waste time designing something you don't want.
 

danadak

Joined Mar 10, 2018
3,607
https://startingelectronics.org/beginners/circuits/two-colour-LED-flasher/

A possibility.

You can do this with one chip, an ATTINY85, if you work with processors.
power would have to come from a regulator. Using mBlock graphical programming tool -

upload_2019-7-4_10-54-1.png

555 timer approaches -

https://electronics.stackexchange.com/questions/251867/how-to-alternate-2-led-strings-using-555-ic

https://forum.allaboutcircuits.com/threads/555-timer-alternating-blinking-led-circuit-issue.45180/

http://solderpad.com/psd/railway-crossing-lights/


Regards, Dana.
 

Thread Starter

SanctuCaryCustoms

Joined Jul 4, 2019
6
Welcome to AAC!

Draw a picture of the waveforms you want so we don't waste time designing something you don't want.
I just want one colour on for a second and then the other colour on for a second and back to the start. I found how to do it using a 555 timer chip but that uses a switching polarity common.
 

Thread Starter

SanctuCaryCustoms

Joined Jul 4, 2019
6
Thanks for the reply. I think I’ll give the second one down a try. I didn’t think about using the 555 timer unit to control a pair of transistors
 

dl324

Joined Mar 30, 2015
9,111
Thanks for the reply. I think I’ll give the second one down a try. I didn’t think about using the 555 timer unit to control a pair of transistors
You can do it with a 555 timer and one transistor:
upload_2019-7-4_9-52-22.png

You can get approximate component values using this graph:
upload_2019-7-4_9-55-5.png
 
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