Switching LEDs - Page 2 - Electronic Circuits Projects Diagrams Free

skeeterb · 10th January 2008, 09:40 PM

Quote:

Originally Posted by k7elp60

I still think we can do it with out a lot of circuitry. If the Refill terminal has no voltage until the yellow LED is turned on and the warning terminal has 12V when you want the orange LED operate on both conditions(flashing/not flashing) it can be done two ways one with a 555 timer and an additional transistor(NPN). The other way is with a flashing LED and two transistors(1 NPN and 1 PNP). Both circuits would require a few extra parts but no additional IC's
I am going out of town for 2 days so I'll check when I get back.
As a side note: If the Power,Operation,Warning and Refill terminals have either no voltage or +12V with respect to ground the diodes connected to each LED is not necessary.

That's mainly what I was thinking about, using transisitors and an ASTABLE 555 circuit to make the LED flash when the REFILL LED is lit and burn stable when the REFILL LED is off. the Power LED is lit while the entire system is turned on, the Operation LED is only lit when the the pump is off, the valves are closed and the PWM and recirculation pump are running. When the water level gets below the Upper Water Level Sensor, the WARN LED lights up and burns steady, until the water level gets below the Lower Water Level Sensor and the REFILL LED is lit, the PWM off , the recirculation pumps off, the refill valve open, and the refill pump on.

k7elp60 · 12th January 2008, 02:21 PM

Here is the circuit I came up with. Hope this helps

skeeterb · 12th January 2008, 03:05 PM

Thanks for your help man. I posted the other part of the circuit that this circuit is a part of. I'm not sure of it put see what you think. http://www.electro-tech-online.com/e...cuit-help.html.
Like I said to RadioRon I'm a NOOB when it comes to designing circuit diagrams. That circuit was really my first attempt at designing a circuit. And to think it started with me messing around with some wires and relays that come off of buses when my step-dad/Boss changes the motors on the Crossing gates on a school bus.

Edit: I've completed this portion of the circuit, now all I have to do is do a copy and paste of this circuit onto my control circuit drawing and the circuit will be completely finished.

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