I want to control via Arduino a peltier cooler/heater that uses a DPDT on-on-on switch to set the voltage at the terminals of the peltier cell to +12 V, 0V or -12V. I have measured the voltages at the six terminals of the switch and the voltages in the three configurations are as shown in this figure: The terminals at the top and at the bottom of the switch are set to either 0V or 12V as in the figure (voltages written in black). The position of the switch forms the colored junctions that set the voltages in the central terminals.
I would like to use an Arduino to control the voltages of the central terminals in a way analogous to the switch. I was planning on doing this by using relays, but I'm unsure how to do the wiring and if I need a 4-channel relay of if a 2-channel relay is sufficient. Do you have suggestions? Thank you.