Using the NI USB-6009 to generate a 12VDC output and 300mA output current

[Scall93]

Hi,

I am using the NI-USB-6009 as my power source for a 12VDC solenoid valve with current drive of 300mA. Originally I used a non-inverting Op-amp circuit and inverting Op-Amp circuit to get the + 12V and -12V output but I could not get the current I required. Should I use a transistor??

Please find pictures attached. Any input would be appreciated.

Thanks,

Adam

[crossrulz]

Yes, you should be using a transitor circuit to turn your 12V to the solenoid on or off.

Each Digital Output of the USB-6009 can only supply 8.5mA, so you may want to get a buffer IC that can supply more current to your transistor.  To make your logic easier, I would use an Inverter chip.

[Scall93]

Can you please elaborate on that? I have a switch in my VI which outputs 5VDC from the digital pinout when switch is on and 0V when its off. Where would you put the inverter chip? Will this amplify the current? Thanks for your help.

Adam

[crossrulz · Accepted solution]

Well, it really does depend on your transitor circuit.  But most systems I have used use the transistor to set the voltage to the device to 0V.  So when your DIO is high, the output is actually 0V (low).  So by using an inverter chip, your output of the DIO will sort of match the output of the circuit.  If you get the right IC, then the inverter will also give you some extra current to drive your transistor.

[johnsold]

The ULN2003 will do what crossrulz is suggesting. It works nicely at 12 V and 300 mA with no extra circuitry required. It includes clamp diodes to protect the transistors from inductive spikes. It has 8 inverters/drivers in one 16-pin package.

Lynn

[crossrulz]

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@johnsold wrote:

The ULN2003 will do what crossrulz is suggesting. It works nicely at 12 V and 300 mA with no extra circuitry required. It includes clamp diodes to protect the transistors from inductive spikes. It has 8 inverters/drivers in one 16-pin package.

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Just leave it to Lynn to have a part in his head that does everything I have ever wanted.  I'll have to save this one somewhere.

[johnsold]

I have a couple of parts on my desk, too.

Lynn