usb6009 and uln 2003 controls relay

[sahana3]

Hello all,

Let me explain the part I need help with.

I have a driving uln2003 which is connected to the digital o/p of usb-6009. This driver ic is in turn is connected to the 5Vdc Relay(RW-SH-103D). I have generated a square wave of 0.5 Hz in a VI at the port to dim and dip the incandescent bulb switched by the relay. 

Problem- The program stops after 3-4 seconds and an error pops saying the usb is not properly connected.(error-50405)

If I don't connect the mains supply and just see the functioning of the relay, it works properly. Is it that the USB-6009 isn't able to take the load. But why is this happening even after the Darlington pair and relay?

Kindly suggest me a solution.

Best Regards

Sahana

CLAD

[johnsold]

Are you powering the ULN2003 and the relay from the 5 V output of the USB-6009? It may be that the total load is too large for the USB port or an inductive spike from the relay coil coudl be causing problems.  Try powering everything except the USB-6009 from an external power source (with the ground connected to the USB-6009 ground, of course).

Lynn

[SnowMule]

Why's the ULN2003 tied high?  Tie it to ground and sink the current rather than sourcing it.  You're probably overloading the DO's on the 600x, which will cause a USB reset.

[apok]

did you connect like this?..instead of the 12VDC power supply, make it a "separate" 5VDC..do not connect it to the +5VDC supply of the Daq

[sahana3]

Hello Lynn,

I had a different circuitry earlier where I was using a 12V relay and there I had used an external power supply to power the driver circuit and relay. I experienced the same error in that too. Hence, I changed it to a 5V relay to use the USB-6009's 5Vsupply. And the error remains.

Thank you

Sahana

[Shivansh]

Hey Sahana

Let us know the results of the suggestions that have been posted.

Shivansh

Applications Engineer, NI 

[sahana3]

Hello Apok,

I have the same setup as shown in the circuit shown. and I am using 10W incandescent bulb. The error remains. With the 12V setup, the program ran for more number of cycles(30-35seconds) before it showed the error, whereas now it runs for hardly4-5 seconds with the 5V relay. The setup is same for both the relays. I connected ULN2003 to an external 5V power supply as suggested, but coudnt notice any change.

Regards

Sahana

---

@apok wrote:

did you connect like this?..instead of the 12VDC power supply, make it a "separate" 5VDC..do not connect it to the +5VDC supply of the Daq

---

[sahana3]

Hello Shivansh,

As mentioned, I tried all the possibilities, but failed to make it work. I have used berg sticks to mount the relay on the PCB. Can that be the reason? As the berg stick's current rating is 1A.

Regards

Sahana

---

@Shivansh wrote:

Hey Sahana

Let us know the results of the suggestions that have been posted.

Shivansh

Applications Engineer, NI 

---