swicthing circuit

Thread Starter


Joined Aug 20, 2006

I want to make a circuit that when a pressure/push switch has been activated for 4 seconds it then activated an infra red led. The infra red led must then stay on all the time until it is reset by a reset button.

 The infra red led will need a battery to power it up 24 hours once it has bee activated. Could you tell me what kind of battery I could use (the smaller the better)?
 The led I hope to use is kingbright KM-4457F3C

Part No. KM-4457F3C
Material GaAs
λP(nm) 940
Lens Type water clear
Po(mW/sr) @20mA *50mA Min. 0.8
Po(mW/sr) @20mA *50mA Typ. 5
Viewing Angle 2θ1/2 150º

The switch just needs to be a small push switch or pressure switch like a micro switch.
The time period that the chip counts to when the switch is in activation doesn’t have to be that accurate (around 4 seconds) .

I believe I will need a counter e.g (555 chip) and another chip. Would you be able to draw the circuit full as I only know the basics. And also write down the resistor/parts sizes I will need to make this circuit.
I would be extremely greatful if you could find the time to help me out.