The circuit uses 2 relays 2 limit switches and a dc motor.
Dc motor limit switch circuit.
When you switch off power to an ac circuit a voltage spark or arc is created.
Imagine you have two circuits each carrying the same current one is an ac circuit and the other is a dc circuit.
The interlocks are specially important because if both relays are on it would be a short circuit.
I have attached a schematic using push buttons instead of limit switches.
Any help in amending the code to include the limit switches would be greatly appreciated as i am a bit out of my depth.
Used to vary the pwm of the pulses at the output and which eventually is used for the speed regulation of the connected motor.
The switch s1 is used to instantly reverse the motor direction whenever.
A very cool and easy dc motor speed controller circuit could be build using a just a single mosfet a resistor and a pot as shown below.
Since diode cr1 will not conduct with a negative potential across it the motor will stop.
When the control switch is held in the right position the motor runs until the right limit switch opens.