Digital pot control with 6024E

[Dhia25]

Hello everyone  ! I’m a student  and i have got a college project about speed Subjugation of a DC Motor ( 60V ) , so i got a PWM speed controller for the task ... this speed controller includes a physical 100kohm pot to control the PWM modulation ( 100kohm = 0V = 0 RPM , 50kohm = 2,5V = 5000 RPM ) 

so the problem is that i burned the circuit while manipulating because i took off the original pot and inserted the 3 wires to the NI card which is 6024E series.

So i bought a digital pot to replace the old one and make it more secure, now i’m stuck on how to make a loop to control this digital pot in order for it to send the correct voltage ( i’m using an optosensor on Motor shaft in order to get the instant speed value and compare it with a give value that the user chooses before running the loop) 

i really need help i have a week to make this work !!! 
thanks for listenting.

[santo_13]

Assuming that the PWM controller potentiometer is used to provide a 0-5V signal, you just need to connect the GND and Signal wires to the AO channel of DAQ card.

The mistake was that you had connected the 5V line from the controller to the DAQ car. If this 5V was connected to an AO or Output of DAQ, one or the other would have damaged because of the difference in levels.

If and only if the PWM controller can operate with just 0-5V signal, the following connection should allow you to control the speed,

Speed controller GND -> AO GND on DAQ

Speed controller SIGNAL -> AO0 or AO1 on DAQ

For safety add a 1k resistor in the AO connection between DAQ and Speed Controller

Sharing the Speed controller datasheet will be helpful to suggest you the right connection.

[Dhia25]

Thanks Santhosh for responding so quick, i did exactly that ... by connecting the signal wire to the AO channel with the GND wire i didn’t connect the red 5V wire, talking about the speed controller i bought it online and it’s brandless without even a datasheet ... even searched online but didn’t find any related documents, well i bought a new one and îm going to use your advice to add a 1K resistor.

Any suggestions about the labview loop i should use and the signal type ? 
i want to make another loop for the optosensor signal and compare it with a speed value that the user enters beforehand and make it Subjugation. 
thanks again ! 🙏

---

@santo_13  a écrit :

Assuming that the PWM controller potentiometer is used to provide a 0-5V signal, you just need to connect the GND and Signal wires to the AO channel of DAQ card.

The mistake was that you had connected the 5V line from the controller to the DAQ car. If this 5V was connected to an AO or Output of DAQ, one or the other would have damaged because of the difference in levels.

If and only if the PWM controller can operate with just 0-5V signal, the following connection should allow you to control the speed,

Speed controller GND -> AO GND on DAQ

Speed controller SIGNAL -> AO0 or AO1 on DAQ

For safety add a 1k resistor in the AO connection between DAQ and Speed Controller

Sharing the Speed controller datasheet will be helpful to suggest you the right connection.

---