Dart Potentiometer Wiring

[Herbie_3633]

My team just got a Dart Linear Actuator and sensor kit but be can't figure out the wiring for the potentiometer.

[Mark McLeod]

The pot has three connectors that should be marked on the case as to what each is.

• ground
• signal
• power

It connects to an Analog input on the roboRIO.

[Herbie_3633]

The connections are labeled 1,2, and 3 and a wavy line connecting 1 and 3 but there is no clear indication of what is ground and power.

[Mark McLeod]

1 & 3 connected by a wavy line should be ground and power. The order only changes the direction of the pot.
So 1=ground & 3=power might mean that turning counter-clockwise increases the signal,
while 3=ground & 1=power would be the opposite and clockwise increases the signal.

2 should then be the signal.

Does the pot have a make/model #?

[Herbie_3633]

The brand is Bourns the part number is 3590S-2-201L

[Mark McLeod]

So yea,

• 2 = signal
• 1 = ground
• 3 = power

power on 1 would be CCW (counter-clockwise) increasing
power on 3 instead would be CW (clockwise) increasing

In the schematic, the signal contact slides from left to right when the pot shaft is rotated clockwise.
So if 1 is ground, the signal when close to ground will read 0 and will increase as it moves right (CW shaft rotation).
If 3 is the ground, the signal when close to power will read nominally 5v (~4.8) and decrease as it moves right (CW shaft rotation) and gets closer to the ground.