Ok I'm feeling dumb right now. I got one of these momentary dpdt switches and can see via ohm meter that the middle terminals are normally connected to one of their corresponding edge terminals when the switch is "NOT pushed." However, when I push the switch, I see the connection broken on the terminal that was previously connected, but I also expect the middle terminals to be connected to the "other" set of edge terminals. However, I don't see continuity. IOW, I expect the dpdt functionality explained in this article, albeit a toggle dpdt. I want to hook this up as a "normally off" switch rather than a "normally on" switch. I do need a dpdt since I need it to control two circuits. I have used TWO different ohm meters just to make sure. What gives?
How does a momentary dpdt switch function
dpdtswitches
Related Solutions
Use any two different color LEDS reversed in parallel with a single R to limit current like 1k and connect across switch (to mechanical device).
Do you have +7 or -7V to load or +- V where V = 5 to 12? Latter I guess.
LEDs will be selected with polarity and protect themselves from excess reverse voltage .
Believe it or not, that black lump is epoxy covering an integrated circuit, probably a small microprocessor. These are often caseless chips, just the IC die glued to the PCB with fine wires between the pads on the chip and PCB.
Many microcontrollers can be put into a deep-sleep state where they draw just a few microamps, so little so as not to significantly affect battery life. They spend all of their time in deep sleep until someone presses the button, which is connected to an interrupt line to wake it up.
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Best Answer
There is no guarantee it will be the center terminal that is common. Just probe it out. It will almost surely be symmetric on either side, but it may be one of the end terminals that is the common for each side.
In any case, there are only two 'states' for the switch, so write down what is connected to what when the plunger is pressed and what is connected to what when the plunger is released. If there are 6 connections you need to make a total of 30 continuity tests (5 + 4 + 3 + 2 + 1 for each state) to be completely systematic about it. If you short a few together and have a good guess you can cut it down to just a few tests.
Edit: Here is a similar looking part, and the middle indeed is the common: