Most cockpits, mine included, start with just a simple toggle switch. These are easy to use, easy to mount to a panel, and easy to wire up. There are however, multiple different types of toggle switches.
Toggle switches are actuated by moving a lever back and forth to open or close an electrical circuit. There are two basic types: maintained contact and momentary contact.
Maintained contact toggle switches maintain the position to which they are moved or actuated. Momentary contact toggle switches do not. Have a read here for more info.
The types I used in my cockpit are;
- OFF-ON: A simple two position toggle switch. One way is ON and completes the circuit, the other is OFF on the circuit is closed. There are 46 of these in the cockpit.
- ON-OFF-ON: This is a simple three position toggle switch. The lever clicks into three positions, down is ON and one circuit is complete, middle is OFF the circuit is broken, up is ON and the second circuit is complete. Note that there are two seperate circuits, sharing a common ground. There are 22 of these in the cockpit.
- OFF-(ON): A simple two position toggle switch, however the ( ) indicates that the ON position is momentary and the lever will not lock into place when you switch it. You push the lever up, and the circuit will be complete. When you let the lever go, it will spring itself back into the OFF position and the circuit will be closed. There is only 1 of these in the cockpit, the JTSN switch on the CMSP.
- (ON)-OFF-(ON): Another three position toggle switch, this time momentary in both ON positions. It will stay in the centre OFF position, and will have to be held in the up or down position to complete either circuit. There are only 4 of these in the cockpit.
- ON-OFF-(ON): Similar to the above switch, but only one of the positions is momentary. The lever will lock into the middle OFF and upper ON positions, but will need to be held in the lower ON position as it will spring back into the OFF position when released. There are only 4 of these in the cockpit, all on the CMSP panel.
I choose early on in my project to try to keep costs down, so not many of my switches are real milspec aircraft items, most are just cheap eBay toggle switches and rotaries. But if you are chasing absolute accuracy, there is a fantastic list of all the real switches in an A-10C, with part numbers and links, compiled by ED forum user Deadman right here.
I did make a few exceptions and spent a little more:
- I sourced some real Cutler Hammer switches that were old and relatively cheap on eBay
- I found some NKK locking toggles, again sourced on eBay
- I have a real Honeywell Landing Light Switch, sourced from Digikey. It was about $85 AUD.
All of the better switches above follow the same principles of the cheap ones, they are just made from better quality materials and have a much better feel when actuating them.