Hi, I am looking to construct, what I think would quite a simple circuit= =
to monitor battery voltage on my motorcycle, showing a normal, overvolta= ge =
and undervoltage condition.
Does anyone have any ideas or sample designs that may do something like = =
this? Was thinking of driving a tr-coloured LED.
Thanks in advance.
Hi, Black. I'm going to make a guess that your "tri-colored LED" is one of those two-lead LEDs that are actually back-to-back LEDs, one red and one green. If you bias the LED one way, the red one lights; bias it the other way, and the green one light. If you can arrange to reverse the bias over a hundred times a second, it seems like both the LEDs are lit, and the light output from the diffused lens seems to be kind of an orangish yellow.
If that's the case, let's first look at making it light up yellow. In order to do that, you could use something like this circuit, based on the 74HC14 (a hex CMOS inverter with Schmitt trigger input) (view in fixed font or M$ Notepad):
| | .-----------------------. | | ~ | | | |\\ ___ ~R | /| | o-|H>O-o--|___|-o->|-o--o-OO-o--|___|-o->|-o--o-OO- | | '-' |Dual Comparator | |.01uF | |/ | | | | |\\ | | === | | o--)---|-\\ D ___ | === GND | | | | | >-o-|
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