Usb 6008

[automatizate]

Hi alls!!!!

I have NI USB 6008, when I connect the Outputs to relays, theses reaay not working, if the output no have the relay connected the output deliver 5 volts, but when i connect the relay I not have Voltage, what i need to do? to fix this issue.

 Thanks

 Best Regards

[odessy27]

Did you look at the specs of realys? USB 6008 has only 5mA of current drive and most of the relays would need higher current drive.

[apok]

no problem driving 5vdc SSR(solid state relays), but if you have a coiled relay..use a low side driver (depending on your relay's current needs). ULN's supplies around 500mAh and Mosfets can supply alot more...

[g_e_m_i_n_i · Accepted solution]

Also, assuming that the USB 6008 doesn't have enough current to drive the relay, it is pretty easy to use a transistor as a switch, assuming you have another power supply available. 

Page 3-4 has very good tutorials for this:

http://venus.ece.ndsu.nodak.edu/~glower/ECE376/L_Fa10/107_Transistors.pdf

[sebster]

Just an additional idea on this....

Terminal 31 provides a +5V output rated at 200mA which is taken from the USB. I've used this to drive a circuit with 4 low-power relays using transistors from the digital outputs as described above without any issues.

If your circuit and/or relays require more current, then you will need an external supply.

[hugosantos]

Hi,

How I made a circuit of the low power?

I want use the USB 6008 to turn on the led of the 24vdc, if I use only a coil relay to turn on?

Regards

[apok]

this might help you...

[hugosantos]

The present reley is coil? If I use a ULN2003A before to relay, my application will working?