I'm working on a project and need a red led to slowly glow to full brightness and when full on I need a white LED to light and both LEDs to go out at the same time. It doesn't have to be a repeating cycle

I've only done simple 555 and 4017 led chaser circuits so this effect is beyond me.

 

Not exactly as requested , but it's a start.Adjust R5 so full red LED brightness is reached by end of 10 sec timing cycle when 1/2 sec 555 is triggered to turn on white LED. D4 adjusted to give rapid discharge of C2.

 

Not exactly as requested , but it's a start.Adjust R5 so full red LED brightness is reached by end of 10 sec timing cycle when 1/2 sec 555 is triggered to turn on white LED. D4 adjusted to give rapid discharge of C2.

What are you talking about?

 

Acidently hit post ,I guess

 

Ah, caught you mid edit. You seen this one? It works well, but the power supply has to be 9V.

Seems to me that you could add a white LED/resistor from pin 3 to Vcc and get the same thing.

 

Ok. thanks I'll try building those.

I'm trying to get the effect of a star trek photon torpedo launcher from the 1st movie. red building to intensity and a white flash at fire. There is a prebuilt lighting circuit for it, but I'd rather build it myself.

 

To shorten C2 discharge time, use an N-ch FET with an RC delay on gate, 2/10 th sec or less depending on burst time. To change C2 charging from expotential to linear try a constant current source ,replacing R4, such as LN334 adjusted for about one mA.

 

Will try thread again

 

may i ask a question? what is the unit of the capacitors in last circuit??? is it uF? or pF? and what type of capacitor was used? also, what diode was used?