Hysteresis Controller with Op Amps

163

02:18:16

Hello this is a real prototype for a project that I am working on. The machine needs to compress air and keep that air between 4-6 psi using this controller. The relay in this circuit is used to power a compressor that pumps air into the machines air tank. In the circuit i have replaced the tank with a capacitor in the bottom left corner. Although it stores charge rather than air it is analogous to an air tank with voltage rather than pressure. FYI all op-amps are in a single IC and are supplied with 12V and 0V. If you have any questions or concerns about the circuit please post below.

published 10 years ago

faceblast

10 years ago

how are you interfacing to your pressure sensor

Addramyrz

10 years ago

Pressure regulator valve... Save the trouble.

rich11292000

10 years ago

That will not turn off the motor though

rich11292000

10 years ago

It looks like every circuit is the only interface. The configuration of components is the program. Breadboard serves as software.

hurz

10 years ago

Put a small cap to ground at feedback node and EC is happy http://everycircuit.com/circuit/6298970435878912

thebugger

10 years ago

Yes i have the same question. How do you interface a manometer to an electronic circuit. What's your mechanical-electrical link?

hurz

10 years ago

Check your washing machine, there us one to indicate the water level

MrWilson

10 years ago

We will have the sensor connected to the tubing between the compressor and air tank. Also i should mention that the air pressure is used to push fluid out of the tank. The fluid can only come in contact with special silicon tubing and the reservoir tank. A paristolic pump isn't really ideal for our project which is why we're using a pressure system. And thanks hurz, will do.

MrWilson

10 years ago

Okay added the cap, a fly-back diode for the relay coil, and also a switch for power sources incase you guys want to manually control pressure feedback.

MrWilson

10 years ago

I may add a capacitor to represent the air tank. Just pumping charge into the capacitor rather than air into a tank :) then we can have true feedback in the circuit

hurz

10 years ago

A model of a Quiwag this would be interesting. Quiwak (this is how i thing its written) so i just heard it many times. Its a tank with water and 2/3 of compressed air around 2bar. This is used to keep the water pressure in our house high enough ;-)

faceblast

10 years ago

I just bought a compressor and it has a similar feature, it starts if below 85psi and stops at 135psi. but I can't see how its actually detecting what the pressure is

JeffreyH

10 years ago

@faceblast, a presssure switch is a single throw switch connected to a diaphragm biased by two springs that controls the cut-in pressure, the switch may be single or double pole. Other features may include a manual bypass and an unloader valve, which allows for a no load start of the compressor.

MrWilson

10 years ago

Okay added capacitor in place of the air tank so we have some feedback now :D

hurz

10 years ago

Nice

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