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[on:]

Hello, I have an actuator that I need to supply a 2-10v signal to. I've been doing some searches and have read I should use an op amp to do this. I've read that to get a 0v output a rail to rail type op amp needs to be used, but since 2v on my actuator is my 0 position I'm ok with just a regular opamp right?

I'm a bit new and I was hoping someone could show me diagram on how I might wire the arduino up to the opamp and also which opamp would be best for me?

Thanks in advance!

[Reply #1 on:]

The opamp need needs a supply voltage. A rail to rail be able to generate an output signal which is nearly as high (or low) as its supply voltages. If your supply voltages is 0 to 15V, you do not need a rail to rail opamp.

However, I like the TS912, a rail-to-rail device, which can be used as a single or dual supply opamp.

Oliver

[Reply #2 on:]

Thanks for the reply Richard. The power supply for the actuator is 24vac. I can tap into it but I feel like that would create other work :-) and another set of questions on getting from 24vac to 12vdc. For the arduino I just planned on using a battery pack of some sort for the short term.

[Reply #3 on:]

Here's a circuit that might do what you want:

http://ruggedcircuits.com/html/circuit__20.html

Now, I'd be more concerned about this "actuator". The circuit (and any op-amp) will give you a voltage but only if no current (or "fairly little" current) is drawn from it. Do you have any info on this? I'm also concerned about the whole 24VAC thing. Maybe give us some more info/details on the actuator?

--
The Aussie Shield: breakout all 28 pins to quick-connect terminals

[Reply #4 on:]

The actuator is a Belimo type, used for air control dampers. Input impedance is 100kΩ for 2-10vdc (0.1 mA), and yes the power supply is 24vac which is pretty common in the hvac world.

Thanks for the circuit! very helpful!

Basically what I'm trying to do is set up a small testing tool. I'm having about 200 of these actuators installed and I wanted to test and verify them easily and quickly before having them wired up to our building automation controllers.

[Reply #5 on:]

That should work then, as long as you have a common ground connection with the actuator (or connect the Arduino ground to the return path of the 2-10VDC input if it's a separate pin).

--
The Rugged Motor Driver: two H-bridges, more power than an L298, fully protected

[Reply #6 on:]

Thanks everyone for your help I'll let you know how it turms out. Hopefully no smoke to be reported back.