3 LEDs 2 toggle switches and no ideas

[813_Error]

I got these 2 toggle switches that control a few of my many fans, well I also have these 3 LED's that I pulled out of something that I put in the floppt drive cover along with the switches. The lights are red, yellow, and green. I want a little temp stop light kind of effect. When both switches are off only the red is on (O no!), when either of the 2 switches are on the red and yellow lights are on (Better not decode anything! lol) and finally when both switches are giving power to my fans all three lights are on.

These switches have 2 sides on the back so I can control more than 1 thing. Right now Im cutting the ground from my fans(safer that way) but from the mental picutre Im getting I will need to put positive on one of these switches for the green light, I dont know how safe that will be.

I checked and they run off 5v so Ill just pull from a fan or 2 for the LED's power.

Any suggestions/comments?

[matttheniceguy]

umm.... most fans are 12 volts, which would melt the led's nicely, so cheack that first. 5 volts might be too much too, they might get hot and die young. usually about 3V is what they like.

Asside from that... the crazy switching problem.... ummm....

I can't really think of a way of doing that without using transistors

You would have to set up a bit of a logical gate with them.

ie.

IF switch 1 = off AND switch 2 = off, red on.
IF switch 1 = on OR switch 2 = on, yello on.
IF switch 1 = on AND switch 2 = on, yello off.
IF switch 1 = on AND switch 2 = on, green on.

I know that logic bit is a lot more obvious than how to get transistors to do this, but honest, it's not that hard to get them to do it, you just have to read up on how to work them.

Good luck, that sounds like a pretty cool idea:)

[Black_Ops]

ummm just wondering, why are you disconnecting the negitive on the fans???? in practice you should alawys disconnect the POSITIVE for safety, here is the reason.

(imaginary situation)
say you just wired up a 480v machine.
you wired everything so it was

positive-------load----switch----negitive
(as your described as being safer this way)

insted of wiring it like it should be

positive----switch----load----negitive
(the correct way for safety)

and someone elses comes to fix a motor on it. so they turn off the disconnect switch for the motor.

they then go to the motor an start disconnecting it, except they get a horrible shock when they accidently touch the hot wire they disconnected.

now they got this shock becuase the floor of the shop is ground, and your disconnect disconnected the ground wire, leaving the hot wire hot (because the machine was still on and only the motor was off) so the power from the hot wire went throught the person into the floor of the shop.

now if you had done it the correct way the positive would have been disconnected and only the ground would have been connected which is harmless.
(end situation)

now for your question you can get some logic gates from your local electronics shop, they have and gates and or gates which you can hook the outputs upto transistors to drive the led's. rember to use current limiting resistors or zener diodes to get the correct voltage from a 12v line.

[ares350]

it depends on the led for voltage, typicly yellow and red like around 2.5volts, green prefers 3.2ish. depends heavily on who made them.

[tbones1337]

if you need.. there is a thing called a "resistor" which cuts down the input of volts... so it can happen, but u will need resisters.