NI 6008 USB help for controling 3 relays.

[roundish]

Hi there! I have a 6008 DAQ, and i need it for controlling three relays for turning on/off lamps, so i have maked a VI for activating the relays through three buttons. My problem is that i don't really know which kind of relay i need. I need something like 5VDC to 230VAC. What do you recommend me?

[AnalogKid2DigitalMan]

I would suggest using a Solid State Relay (SSR). Make sure the input current required to drive the relay is within the specification of the 6008's output current drive capability.

-AK2DM

[SnowMule]

+1 for solid state relays.  Kinda pricey, but it makes handling 120VAC from a digital output pretty easy.

Omron's G3NA series work well, can drive those right off the digital output.

[roundish]

Hi! thanks for taking your time on replying. I will try to buy one SSR with 5VDC to 240VAC. My problem now is that i have this relay ( see the image below ) and let me explain what happens with the DAQ.

First my proffesor gave me this relay, we don't have any kind of datasheet and i can't find it. I have made a VI for using digital line 0 port 0 with ( inverted signal ) so when DAQ is not sending the signal for the relay to work is with 0V and when i click on power it sends 5V. The problem is that when 5V is on port and the relay is connected it only have 2V and 2mA and when the relay isn't connected i see 5V and 5mA. If i connect the relay to the analog outputs and change the program for using them, the same thing happens. If i connect the relay to the 31 port number ( 5V from the DAQ) it works and it uses the 5V and the 5mA. Don't really now if is a problem with the DAQ not giving enough power or what can really happen. Any advice here too?

The relay in the photo have this pins :  - 1  2-     3-

                                                       _|_    |       |

                                                       |   |    ->  <-

                                                       ----        \.

                                                         |          |

                                                       + 5      4-

[SnowMule · Accepted solution]

You'll need a relay driver or transistor to provide current to drive that relay.

Regarding a datasheet for the relay, tried google?  Part number's printed on the side of the relay.

The ULN2003A is a good relay driver.  A 2N4400 transistor will do the job too.  Both are real easy to hook up.

[AnalogKid2DigitalMan]

Snowmule is correct.

Also be sure to add a reverse biased diode (1N400x series) arcross the relay coil to prevent inductive voltage spikes from damaging the transistor or DAQ when the relay is turned off.

The ULN driver may already have this feature built into it.

-AK2DM

[roundish]

Hi! Thanks for all the info you gave me! I have bought today a ULN2003A,  i am testing it now, but i have the same problem again with the daq and chip. I have connected de 1º pin on the chip to the port 0 line 0 in my DAQ, and connected GND too but when i test it with my program it keeps giving low voltage and low current, so the chip can't activate the relay. This is the vi, i founded here in the forum. Thanks for your help.

[JanBarton]

Hi,

few years ago I made board for 8 relay outputs with USB 6008-OEM. Here is the schema. I hope it helps.

Jan Barton