I have a need to be able to connect a lead on a circuit to 1 of 5 different other leads. I think it’s obvious how I can accomplish this with jumpers or DIP switches or encoders.

The wrinkle here is that the voltage is somewhat high ~ 30V.

My question is: is there a electrically controlled way to accomplish this? I’ve looked at multiplexers and some other options but once you get into the 30V range these components seem to get too expensive to justify the cost.

What options are available in this situation?

To summarize, a good solution would:

  1. Allow electronic control
  2. Handle ~ 30V @ .5A
  3. Be low cost — If one component handles mapping 1 to 5 lines, I’d need 5 of them on the board; each of 5 lines gets mapped to one of 5 lines.
  • \$\begingroup\$ How much current does this need to handle? And is the current always flowing the same direction or is it bidirectional? \$\endgroup\$
    – The Photon
    Oct 3, 2019 at 4:57
  • 2
    \$\begingroup\$ I had a quick look at a jumper datasheet: 94V, 3Amps is that not enough? \$\endgroup\$
    – Oldfart
    Oct 3, 2019 at 5:31
  • \$\begingroup\$ if you can switch the low side and can afford to lose volt or so ULN2003 \$\endgroup\$ Oct 3, 2019 at 6:24
  • \$\begingroup\$ Multi-pole lathing relays in a tree arrangement. Each layer doubles your combinations Double pole, quald pole or octapole. \$\endgroup\$
    – KalleMP
    Oct 3, 2019 at 7:18
  • \$\begingroup\$ Updated my question with some details... Current is always going the same direction. I have to switch it on the low side -- I can't change that aspect. \$\endgroup\$
    – jsinglet
    Oct 4, 2019 at 1:59

3 Answers 3


There are devices called (UK) uniselector, better known in the (US) as a stepping relay. A few of these should do what you want. They use to use a variation of these in the old phone COs (Central Office). Basically they behave as a selector switch but power driven with a stepping coil. You need to pulse it for each position you want to move it. The ones I am familiar with are break before make on the contacts. They were available at one time as a combination, where it would step up to one of 10 rows then step over from 1 to ten locations. Here is a good article by Automatic Electric called "How to use Roptary Stepping Switches. https://www.telephonecollectors.info/index.php/browse/bc-switching-library/automatic-electric/ae-switching-docs/10539-how-to-use-rotary-stepping-switches-automatic-electric-1964-ocr-r/file Rotary switches are still available from several sources.


I recommend relays. Each one normally does 2 outputs, so you'll need to chain them.

chained relays (source: http://zone.ni.com/reference/en-XX/help/375472H-01/TOC1.htm)

  • \$\begingroup\$ I worked this out previously but to do this for each line I’d need 12 relays, which just seems like a lot and very expensive on a component level. It would be like 30 bucks just for the relays. \$\endgroup\$
    – jsinglet
    Oct 4, 2019 at 2:40
  • \$\begingroup\$ That is, with 3 relays I can connect one channel to one of the other 4 channels. I just need to do this for the other 4 channels as well. \$\endgroup\$
    – jsinglet
    Oct 4, 2019 at 2:42

It depends on which way the current needs to go, if the is going from a load to multiple sources and only goes in one direction from a higher to a lower voltage then using FETs would work.

Otherwise some other options are solid state relays which can sometimes be found in the below dollar range for the current and voltage the design needs. Make sure the SSRS have FETs and not triacs


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