Using DAQ as relay/switch w/ Labview?

[dagda99]

Hi!

I'm trying to make the DAQ somehow act as a switch to turn on an external LED lamp.

Running Labview 7.1, M Series Multifunction DAQ (PXI-6251)

Basic idea is that we have a lamp that we want to turn on upon certain conditions in a Labview program. First idea was to power the lamp straight from the DAQ board, analog out signal into the power of the lamp. But, the DAQ doesn't provide enough power (I need 12V @ 1A).

So, the new idea is use another power source, with some sort of switch triggered by the daq board in between. So, was wondering if there was a way to make the DAQ board itself act as software triggered switch, i.e. with some Labview command, two pins on the DAQ are connected (the external power and the lamp)?

I realize that just buying a relay would work, however the one's we've purchased require a higher amperage output than the DAQ can supply, and so was hoping there was some way to program this kind of circuitry on the DAQ itself

Any ideas?

Any thoughts are much appreciated.

Thanks!

-Dagda99

[AnalogKid2DigitalMan]

A basic trasistor circuit, or a buffer or driver integrated circuit (TTL compatible) connected to a digital output (not analog) of the DAQ card would supply enough current to pull in a relay that could be used to switch power to the LED. Or if the above were rated for 12V 1A drive capability, then no need for the relay.

I think somewhere on this site there are articles about such circuits and chips used to interface DAQ cards to drive external higher powered loads. There are commercial off the shelf solutions that are easy to implement.