I would like to produce a small circuit that will allow me to turn on a green led when nothing is happening and swap it for a red led when I press and hold a button.
I am wondering if a monostable multivibrator like this one will do
If I connect another LED between the collector of the left transistor and earth or the collector of the right transistor and vcc (with a resistor) do you think this will work?
If the switch is held on does the circuit stay in its unstable state until the switch is released?
I am wondering if a monostable multivibrator like this one will do
A monostable gives you a fixed width pulse output in response to a level change or edge. So that does not sound like you want it to from your description. It sounds like you want a missing pulse detector.
Having done more research, do you think it is possible that this would do the job just as well?
If I connect one LED between Vout and earth and the other between Vout and VCC (with resistors).
If the 'Vin is five volts and a lead is taken from the base, via my switch to earth.
Sorry Mike I think I was just discovering that, what do you think?
Well that circuit is just a logic level inverter, the two signals will just be the inverse of each other so:-
I would like to produce a small circuit that will allow me to turn on a green led when nothing is happening and swap it for a red led when I press and hold a button.
Will have the lights flashing alternately when you are pressing / releasing the button and just one light on when you hold it.
That is basically what I am wanting. I think I was just trying to complicate things.
I will try to build something and see what happens. Thanks.
Since red LED has lower voltage drop than green you can use this:
Vcc
|
resistor
| —————— pushbutton —————|
G LED R LED
| |
GND GND
You can use this circuit simulator to test your ideas.