Follow-along recipes for the Sandbox. Each one lists the exact parts, the precise wiring, and how to test it. Open the Sandbox in another tab and build right alongside the steps.
The simplest possible build: power a light, then add a switch to break the loop. Master this and every other guide is just more of the same.
Control one light from two locations using a pair of 3-way (SPDT) switches.
Add a crossover switch between two 3-ways to control one light from three locations.
One maintained switch energizes a coil, which pulls in a contactor to run a motor. The simplest motor control.
The cornerstone circuit. Momentary Start and Stop buttons with a seal-in contact that holds the motor running after you release Start.
A real starter: start/stop/seal-in control with an overload relay in the control rung, plus a contactor feeding the motor — control and power circuits together.
A selector that runs a motor manually (Hand), keeps it off (Off), or hands control to an automatic device (Auto).
Wire two coils so they can never both be energized at once — the safety foundation for forward/reverse.
Two seal-in circuits, interlocked, driving two contactors — one wired straight, one with two legs swapped to reverse the motor.
The same reversing job, but with control relays carrying the logic and interlocks, and the contactors doing only the power switching.
Run a motor only while a button is held, by deliberately defeating the seal-in so each press is a momentary burst.
Force motor 2 to start only after motor 1 is running, using a permissive contact.
Control one motor from two locations: stops in series, starts in parallel.
Wire a timer so a light comes on a few seconds after you flip a switch (on-delay), then flip it to off-delay and watch the behavior reverse.
Press a button three times to turn on a light — then wire a reset. The exact circuit to learn how counters behave.