02-10-2009 11:16 AM
Thanks,
It seems you have good knowledge in electrical stuf.
you are saying that making a relay off or on does not depends on the current of my machin. You ment every signal from labview will go through to the coil of relay and current goes to contact of relay. So, is signal from usb-6008 able to open every relay?
If i use the system you said, based on my machine specificcation what will be my relay specification and what type you suggest (NC relay).
the circuit you reffred is usb-6009, so it works with 6008?
02-10-2009 02:10 PM
There are 2 separate voltage/current pairs of numbers that you need to deal with. One pair applies to the coil, which is what activates/deactivates the relay. The other pair refers to the contacts, which is what passes the signal you are trying to switch on/off. There are all sorts of types of relays. Most require more current to activate the coil than what a regular DAQ card can provide. Thus, you typically need some sort of driver circuit to provide enough current to activate the coil. In your case you said that "the relay which will be connected to USB-6008 will recive max 200 mA and voltage is 5 V." Presumably you are talking about the voltage and current required to activate the coil. Since this is more current that what the 6008 can source/sink, then you must have some sort of relay driver circuit between the 6008 and the relay in order to provide the necessary current.