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Analog outputs greater than 5V


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4 replies to this topic

#1 Joey2

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Posted 06 May 2012 - 04:07 PM

I have been using the LabJack U12 for several years now in a variety of projects requiring analog voltage outputs in the range of 0-5V (AO0,AO1). I am beginning a project where I need to generate output voltages on the order of 6-> 8V relative to some external ground which doesn't need to be isolated from the LabJack ground. Is there some simple technique (electrical circuit or possibly IC chip) powered by the LabJack 5V or by a 24V 200mA DC source, that I can use to either double the LabJack AO output or to add a fixed steady offset of ~4V? Regards, Joe

#2 LabJack Support

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Posted 07 May 2012 - 08:47 AM

An op amp set up as a non-inverting amplifier would work: http://en.wikipedia....rting_amplifier

Another option is to use a U3 with the LJTick-DAC. The tick provides two DAC channels with 10V range. Unfortunately it does not work with the U12.

#3 Joey2

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Posted 08 May 2012 - 11:32 AM

Thanks very much for the quick response. The operational amplifier solution should work fine. Regards, Joe

#4 LabJack Support

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Posted 08 May 2012 - 02:10 PM

The U3 User's Guide has some useful information:

http://labjack.com/s...s-guide/2.7.1.2

Figure 2-8 shows a +/-10V output. If you just want something like 0.02 to 10.0 volts, then the non-inverting configuration is simpler. You would do Figure 2-3 in reverse:

http://labjack.com/s...s-guide/2.6.3.5

Either way, the LT1490A might be a good op-amp for you.

#5 jbiele

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Posted 08 January 2013 - 09:21 AM

I have been using the LabJack U12 for several years now in a variety of projects requiring analog voltage outputs in the range of 0-5V (AO0,AO1). I am beginning a project where I need to generate output voltages on the order of 6-> 8V relative to some external ground which doesn't need to be isolated from the LabJack ground. Is there some simple technique (electrical circuit or possibly IC chip) powered by the LabJack 5V or by a 24V 200mA DC source, that I can use to either double the LabJack AO output or to add a fixed steady offset of ~4V?
Regards,
Joe



I did this by adding a fixed 4.5 battery voltage via a relais, which itself can be switched by Labjack AO. See circuit attached.

cheers,
Jens

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