Fork me on GitHub

Project Notes

#244 DPDT Toggle Switches

All about double-pole, double-thow toggle switches.

Build

Notes

A double-pole switch controls two circuits with a single action.

The double-thow nomenclature indicates that each circuit can be switched between two states.

Example Part: DPDT 2.54mm pitch Switch

Product example: 8x8mm Self-locking Push Button Switch

This is a convenient DPDT switch for PCB construction, having a pin pitch of 2.54mm. Unfortunately, the pin rows are only separated by two pitches (5.08mm), so it is one pitch short of a standard DIP layout. This means it cannot directly plug into a breadboard and span the centre line.

DPDT_part

This particular part has the common poles on pins 3 and 6. Other parts may use a different layout; in fact I have come across an identically-looking part with a different (aligned) orientation of the poles. So it is always worth testing before assuming…

DPDT_part_design

Test Circuit

The simple circuit described below demonstrates the DPDT toggle switch. The reverse polarities on each pole demonstrate the isolation.

Operation:

  • when switch is “off” (i.e. not pressed), the red LEDs light on each pole
  • when switch is “on” (i.e. pressed), the yellow LEDs light on each pole

Construction

Breadboard

Schematic

DPDT_protoboard_build

DPDT_protoboard_layout

Credits and References

About LEAP#244 Switches
Project Source on GitHub Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is my personal collection of electronics projects, usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting (IMHO!).

The projects are usually inspired by things found wild on the net, or ideas from the sources such as:

Feel free to borrow liberally, and if you spot any issues do let me know. See the individual projects for credits where due. There are even now a few projects contributed by others - send your own over in a pull request if you would also like to add to this collection.