Hi,
I want to use a tri-colour LED (or maybe just 3 different coloured LED's) to monitor the output voltage of a circuit, to tell me if the voltage is normal (green), too low (amber), or too high (red). I have seen the "Bi-colour LED battery voltage indicator", but was wondering if there is such thing as a 3-stage indicator rather than just a 2-stage.
I would like some links or schematics to assist me. I haven't had much luck using search engines.
Thanks in advance.
You mean like this one from Jaycar
Kevin Martin
to
normal
wondering
luck
For three colours you only need two leds, consider what happens when both are on.
Search for "window detectors".
How about something like this. I will set something up for a car battery. To make up some numbers say one detector(A) turns on below 12 V. The other(B) turns off below 10V. Now with a bicoloured led hook A to the red led, B to the Green.
Batt V DetectA Detect B Colours
9 ON OFF RED 11 ON ON RED + GREEN= AMBER? 13 OFF ON GREENI know that the problem with this system is that Green now becomes the colour for overvolt, but it gives you a start.
HTH
Mike
hmmm, no, I'd rather not have 10 LED's. A tri-colour would be nice, or just a green, yellow and red LED. I'm sure it's possible. But thanks anyway. =)
Umm ok, that sounds like a start I suppose. I'll check it out later on. Thanks =)
Jaycar have an RGB led for $5.95 (ZD-0270). You could also use a bi-colour led. Use the green and red for the normal and high functions, then oscillate the signal to the led to create amber for the low indicator.
Thanks. I'll take that into consideration, as I've read that a 3-pin package is not as common as the 2-pin. Easier to install on a PCB also. Now all i need is a good battery level circuit that will control it for me! I'm looking for a schematic as I want to be able to twink with the components/operation. Like I want to be able to control the low, normal and high voltages with precision, if possible. e.g. 13.6V.
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