I am trying to build a raspberry pi gameboy emulator with a custom board inside of a gameboy adv sp shell. I decided to use an open-source board made by some guy on the internet and I will be modifying a few things on the board such as the power switch to an OEM power switch for authenticity.

My question is as follows: how could I change the schematic from a DPDT switch to a SPST? Images here:

Apparently the DPDT switch is connected to things like keepalive, +3v, enable, shutdown, and the rest of the connections go to other parts of the board.




  • \$\begingroup\$ The transistor appears to be upside down or else it should be an NPN. \$\endgroup\$
    – Transistor
    Mar 23, 2019 at 17:56
  • \$\begingroup\$ the big question is .... why? ........ also, what is open-source board made by some guy? \$\endgroup\$
    – jsotola
    Mar 23, 2019 at 19:10
  • \$\begingroup\$ MMBF5460 is a P-channel JFET \$\endgroup\$ Mar 23, 2019 at 19:53
  • \$\begingroup\$ The two switches have separate purposes, as senor Karas indicates, and the original switch could control a relay as senor Howie indicates, but if what you want is an authentic look(The device being an emulator makes inner authenticity irrelevant), as a second option other than using a DPDT relay controlled by an original switch, you could simply find a DPDT switch that performs like the original(similar dimensions and travel) so that the part exposed to the user can be more authentic. \$\endgroup\$
    – K H
    Mar 23, 2019 at 20:54
  • \$\begingroup\$ Thanks for the comments, I learned a lot and decided it would be best to keep the original power switch. \$\endgroup\$ Mar 24, 2019 at 1:50

2 Answers 2


Use the SPST switch to control a small DPDT relay.

  • \$\begingroup\$ +1. Sometimes the simplest is the best. \$\endgroup\$
    – Marla
    Mar 23, 2019 at 22:10
  • \$\begingroup\$ You know, that is a good idea. On second thought since it apparently works as is maybe ill just stick with the existing switch. \$\endgroup\$ Mar 24, 2019 at 1:49

In this application there is no direct way to replace the DPDT switch with a SPST switch.

If you were clever with electronic circuits, analogue switch components and how to design with them it may be possible to replace the DPDT switch with some circuitry and a SPST switch to toggle it between two states. There is not nearly enough information provided to even be able to suggest a suitable circuit.

  • \$\begingroup\$ would you like me to upload the board and schematic files? \$\endgroup\$ Mar 23, 2019 at 19:03
  • \$\begingroup\$ No. Do not upload the materials. I am certainly not going to figure out a circuit for you. \$\endgroup\$ Mar 23, 2019 at 20:45

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