I am a complete beginner to electronics and am currently trying to work out how to build a circuit switch that will stay on for 5 minutes, switch off for 5 minutes and repeat indefinitely.

I am powering a LED inside a Laryngoscope (medical instrument) with a battery pack made of 2 x cr2032 coin cell batteries. The purpose of the circuit is to test the battery life and light output over time based on 5 minute cycles.

I am concerned that any switch i add may consume too much power and significantly effect the battery life, and that i might be better off with a mechanical solution.

Any help anyone can give me would be greatly appreciated!

 

As this is just a test, you power the timer circuit with a separate supply - battery or wall wart. that way the only consumption from the coin cells would be the LED. This would also avoid the problem of the timer circuit having to work off a varying supply voltage as the coin cells discharge.
What supply would you like to use for the timer?
How much does the LED use?
How accurate does the 5 minutes need to be?

 

being able to plug the timer circuit into the wall would be ideal! but im not adverse to other ideas. I dont have a variable power supply though.

The spec sheet for the LED says its 1W

The 5 minute doesn't have to be especially accurate, its designed to simulate its real life usage in an operating theatre. so for example If it was 5:21 seconds or 4:53 second cycles i could work with that.

 

OK. You say are new to this. Could you construct a circuit?
Would you buy something like this: https://www.ebay.co.uk/itm/DC-12V-D...426b89b8:m:mk7eHC4iVIFrj04k-Uo7o0A:rk:12:pf:0

 

Im a mechanical engineer by training so mechanically i can build a circuit easily enough, and i can follow a circuit diagram if its simple. Although i am still learning this side of things.

The board in that link looks interesting though. So this has its own separate 12v power supply. And this would allow me to adjust the on and off times of my LED circuit?

 

So this has its own separate 12v power supply

You would also need a 12V wall wart to power the board and it has separate adjustments for on and off times (which might be a bit of a pain to set initially but you'd only need to do this once).

 

Great, so if i picked up one of these and a 12V 1A DC mains adaptor, would that be sufficient to power it?

 

Great, so if i picked up one of these and a 12V 1A DC mains adaptor, would that be sufficient to power it?

Oh yes, plenty of power.