Some time ago I was doing work for a company that was tasked with automating the engagement of a piece of survey equipment from an F-150 truck. The covered bed needed to 1open from the top, 2the turret needed to left, and 3finally the equipment needed to turn into position. All at the flip of a switch. Then, when the switch was flipped back, the operations needed to go in reverse.
The company I was working for ended up using a micro-controller and proximity sensors for the limit switches. However I believe this relay-centric design is still a great thought experiment and is worth taking a closer look at. The link to a video of the "laser truck" the circuit was designed for is located here.
I would think this would be a great electrical design for the operation of the landing gear for retractable gear, light aircraft.
There were only a few rules to follow:
Here is the circuit I came up with:
So here is a circuit designed to test AC appliances off the line. It is a momentary power ON button. Then you flip the switch, and it's a momentary power OFF switch!
Sustained Momentary ON Momentary OFF
This circuit essentially takes two lines and runs (in this case) two fans either off, in series, or in parallel. This was developed for a set of two wire fans replacing two three wire fans in a diesel volkswagon golf. The coolant sensor, or the ECU sensor will turn the fans on. To regulate the speeds, one sensor will run the fans in series (half the speed) one sensor will run the fans in parallel (both at full speed).
This is a simple relay circuit used to connect 2 linear power supplies from parallel to serial using only 1 4pdt relay, and the same output wires. The terminals for the relay coil are not shown, but can simply be powered by one of the power supplies and switched with a single pole, single throw toggle.
