I have spent a few years trying to find a rotary switch like this. Always thinking it was a rotary decoder but is not. It turns endlessly but only performs a 5-step fan speed level. If you look close there is a tiny ball in the one picture that has a solid copper ring. When turning, the ball goes around and then hits a stop but the knob can continue to rotate. Until it turns the other direction the ball then goes 320 degrees the other way and hits the stop again. The first picture drops onto the second picture piece.
I suspect, but could be wrong, as the it rotates it increases or decreases in resistance. But putting a meter on it, the resistance steps and isn't linear. I have 4 switches like this that no longer work and appear to have a short across the outer pins which makes contact simultaneously to both outer polls at the same time.
This is the circuit of how it works. It rotates and creates a momentary circuit closure to the fan speed stepper to increase fan speed clockwise and decreases speed counter-clockwise.
I desperate to find a switch that can replicate this. Only other way to make a repair is to buy a whole used controller just to scavenge this switch.
Stu
I suspect, but could be wrong, as the it rotates it increases or decreases in resistance. But putting a meter on it, the resistance steps and isn't linear. I have 4 switches like this that no longer work and appear to have a short across the outer pins which makes contact simultaneously to both outer polls at the same time.
This is the circuit of how it works. It rotates and creates a momentary circuit closure to the fan speed stepper to increase fan speed clockwise and decreases speed counter-clockwise.
I desperate to find a switch that can replicate this. Only other way to make a repair is to buy a whole used controller just to scavenge this switch.
Stu