I am trying to create a "dimmer" with non-dimmable bulbs.

The idea: use 6, 10 or even 20 bulbs (some cheap non dimmable LED or CFL), use a rotary switch that in position 0 lights up none of the bulbs, in position 1, lights 1 up ... to position n where it lights up the first n bulbs without complicated electronics (I am after the cheapest solution possible).

Does such a switch exist? I tried to search for such a thing googling 20-pole switch and 20-position rotary switch, but did not come up with a workable result.

Any help appreciated.

Alternatively I would, but I failed to find it so far, I would like to find an affordable and dimmable high power flood-light (150W LED actual power - 13k-15k lumens) that I can control from a single dimmer switch.

  • 1
    \$\begingroup\$ Even if you had such a switch it would cost way more than a dim feature on LED lamp which is <10% or <5 cents per watt. The obvious solution to me is DC power with PWM. \$\endgroup\$ Oct 20, 2017 at 2:16

2 Answers 2


This isn't the answer you want but I'm a practical man.

I think that if you think about this some more you will realise that it's a nutty way of doing this.

  • You will need a 20-pole, 21-way rotary switch.
  • The first pole will have a wire from position 1 to lamp 1.
  • The second pole will have a jumper between position 1 and 2 and a wire to lamp 2.
  • The third pole will have a jumper between 1, 2 and 3 and a wire ...
  • The twentyfirst position will have a jumper between 1, 2, 3, ...., 17, 18, 19 and 20 and a wire to lamp 20.

You will need a lever to turn the switch because it will be too stiff for your fingers.

If it was a DC circuit you could reduce the switch complexity with the use of a diode matrix. Unfortunately you can't do that trick with AC.

There's a reason we use electronics.

  • \$\begingroup\$ Yes, thank you, I sort of gathered that much. I was hoping for a simple off-the-shelf solution, aka magic bullet, but it does not exist. \$\endgroup\$
    – asoundmove
    Oct 20, 2017 at 0:24
  • \$\begingroup\$ What's wrong with an electronic dimmer? (I know of several applications where they cause problems but what is the problem in your case?) \$\endgroup\$
    – Transistor
    Oct 20, 2017 at 0:30
  • \$\begingroup\$ Nothing wrong really, other than dimmable bulbs are more expensive. Seems like I was trying to be too clever for my own good. \$\endgroup\$
    – asoundmove
    Oct 20, 2017 at 0:46

What you want is called a "cam switch", but I don't know of anyone who makes one with more than 12 positions as a standard product off the shelf. But one of the larger mfrs in the world who brand-labels to most of the other electrical equipment suppliers is Kraus Naimer, and they will make you anything you want, up to 24 positions. Understand though that once you get above about 12 positions, the rotating distance between each step becomes too low for larger contacts, so at 20 positions you may limit yourself to microswitch contacts, so 1 or 2 amps of capacity. Bot for LEDs, that should be OK.

Another mfr is Electroswitch, but at that many positions I think it will be "military" grade and very expensive.


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