3 Switches circuit

Hello I am a graphic designer and not really good at electronics but for a project I have to make a circuit. I thought maybe you could help me. Sorry if the question is dumb.

I have 3 switches. Each of them are attached to a lamp (Red, Blue, and Green). I want at least 2 lamps to be always ON. For example, all of them are ON. We push the blue one off. Then if we push the red one off, the blue one gets on automatically. Therefore, the circuit do not let less than one lamp to be off. Thank you so much and I hope it was clear. Cheers

by sinasina
September 19, 2018

I would suggest a ring of three relays, with contacts interconnected so that only one can be on at a time. Arrange them to turn a light on when off. Make your buttons break the supply to each.

by mikerogerswsm
September 19, 2018

https://www.circuitlab.com/editor/#?id=8c49xqypar9a

by mikerogerswsm
September 19, 2018

Minor edit 'break' should read ' make'.

by mikerogerswsm
September 19, 2018

Full circuit now shown.

by mikerogerswsm
September 19, 2018
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1 Answer

Answer by mikerogerswsm

https://www.circuitlab.com/circuit/8c49xqypar9a

Opens as pdf, use print/export button.

Suitable relay 4 for ten quid:

http://www.rchobbyestore.co.uk/rc-spares-c1/all-spares-c35/omron-g6a-434p-4pdt-pcb-relay-6v-coil-4-5-7-5v-range-pack-of-4-p936

Suitable power: 4 x AA cell in series.

If you use leds put 220 ohms in series with each one to limit the current.

+1 vote
by mikerogerswsm
September 20, 2018
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