Tri-color LED project

Thread Starter

hydra504

Joined Oct 18, 2007
16
Ok I have been working on this project for a while now,
 
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Thread Starter

hydra504

Joined Oct 18, 2007
16
here is the 555 that i build and was testing. it works at 5.5 second. when the swtich is pressed the red led is on. after the 100uF cap is about 2/3 the volatge of the source or VCC. The other green LED turns on.

 

bertus

Joined Apr 5, 2008
19,942
Hello,

In your schematic only one of the leds will glow.
The "yellow" state will not occur as it requires both leds to glow.

Must "green" state remain on after the timing?

Greetings,
Bertus
 

mik3

Joined Feb 4, 2008
4,846
You can use a 4 bit counter (or a 3 bit if you can find). Assume that the outputs of the counter are listed as Q0-Q3, with Q0 to represent the LSB. Then, connect the red led on Q0, the green led on Q1 and Q2 to the reset of the counter. When you give a pulse to the counter, the red will turn on (Q0 goes high), when you pulse again the counter the green led turns on (Q1 goes high) and when you pulse for a third time the counter the yellow led will appear (Q0 and Q1 go high, both leds turn on and make the yellow led). If you pulse for a fourth time then the counter resets and the leds are all off. Of course you can modify this circuit and connect your timer too to have the desired time delays.
 
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