Im just not certein about voltage regulator in post #15. what part to use there

LM317 would be one option.

 

This forum is really awesome! You guys are too! Thanks you so much. Ill give them all a try, just to learn a bit more.

There are five possible LED options:

Discrete LEDs
Red-Green LED - common anode and common cathode
Red-Yellow-Green LED -common anode and common cathode

As is clear from the posts so far, all of them are entirely possible. So the questions to you are -

1. Which is your preferred LED type?

2. What is the max LED current you need?

The second one determines whether or not the LEDs can be driven directly by comparator/opamp outputs, or if driver transistors are needed.

ak

 

Thanks,
preferred LED type is RGY. I prefer the real yellow…
the LEDs are 1.8...2.6/2.8...3.6/1.8...2.6V 20mA

 

I assume you mean a single LED component with three chips inside? y / n

CA or CC?

Datasheet for the LED?

ak

 

They are available both as ca or cc
Datasheet is german im afraid. But i hope you can work it out from the values:

OSTMMA5B31A LED 5mm dreifarbig rot/grün/gelb 3000-4200mcd 5800-7000mcd OPTOSUPPLY
Hersteller: OPTOSUPPLY
Dioden-Typ: LED
Montage: THT
LED-Farbdioden: rot/grün/gelb
LED Diodenstrom: 20mA
Diodenlinse: transparent
LED Diodenausführung: dreifarbig
Front: gewölbt
Gemeinsame Elektrode: Anode
Durchmesser LED-Diode: 5mm
Betriebsspannung: 1.8...2.6/2.8...3.6/1.8...2.6V
Ausgangsraster: 2.54mm
Anzahl Ausgänge: 4
Leuchtwinkel: 30°

 

hi s,
Translated.

OSTMMA5B31A LED 5mm Tricolor Red/Green/Yellow 3000-4200mcd 5800-7000mcd OPTOSUPPLY
Manufacturer: OPTOSUPPLY
Diode type: LED
Mounting: THT
LED color diodes: red/green/yellow
LED diode current: 20mA
Diode lens: transparent
LED diode design: tricolor
Front: arched
Common Electrode: Anode
Diameter LED diode: 5mm
Operating voltage: 1.8...2.6/2.8...3.6/1.8...2.6V
Output pitch: 2.54mm
Number of outputs: 4
Light angle: 30°

 

the seller just sent me a datasheet for the cc. version

 

Operating voltage: 1.8...2.6/2.8...3.6/1.8...2.6V

Because the minimum yellow Vf is conveniently greater than the maximum red and green Vf's, a variation of post #18 will do this nicely. Her it is, updated to use the 11 V zener diode previously mentioned, and 1% resistors in the reference string to tighten up the transition voltages. R5 can be 5%; I don't have that part in my library.

NOTE: The output stage of the LM393 (and 339, 324, and 358) is not super-robust. While rated to sink 16 mA in the low state, the output voltage will rise up from saturated. This means that at high LED current (minimum R6) the red and green LEDs might not starve away all of the current, and the yello LED might be lslightly on. To fix this, add back in one 1N914 in series with the yellow LED.

If you want to run with the full 20 mA LED currents, I recommend driver transistors rather than stressing the IC's output stage. Sch to follow.

ak

 

Thanks! If you have the time to draw in the transistors, it would be great. In ic form preferably due to size. Im in no hurry though.