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  1. johndeverill

    Question about light sensor circ in Projects section

    Hi Ante, Thanks again for the info. Ill try switching the contacts on the relay. With regards to the relay chatter this shouldn't cause a problem but is it likely to wear the relay out quickly? I notice the other circuit has a resisitor to prevent this. Can this be done to the circuit I am...
  2. johndeverill

    Question about light sensor circ in Projects section

    Hi, I've had a look at the velleman kit and it appears that the LDR resistance drops and the input goes high on the Opamp which then in turn turns the relay to the off position. As all I want to do is place the transducer in place of the LDR can do this and then do something such as reverse...
  3. johndeverill

    Question about light sensor circ in Projects section

    Hi Ante, Heres the specs:- Similar to the compensated versions, these devices differ only in null and full scale outputs. Null exhibits a
  4. johndeverill

    Question about light sensor circ in Projects section

    Hi Ante, Thanks for the info. You will have to excuse my ignorance but what is necessary to adapt the voltage divider to my transducer? It has a 10v excitation...
  5. johndeverill

    Question about light sensor circ in Projects section

    Hi All, Been looking at the light sensor circuit... http://www.electronics-lab.com/projects/sensors/001/index.html and it looks like it would work for a circuit I am creating. Basically I want to replace the LDR with a 0-100mV 4-pin pressure transducer so that at a set pressure, rather than...
  6. johndeverill

    7 segment pressure gauge help? Modify voltmeter from Projects?

    Hi MP, I've taken a look and I can see it could display the voltage for me fine. The issue I have is that I want to display 0-30 instead of 0-100mV so that it displays the pressure. Can you point me in the right direction so that I can do the conversion? Many Thanks John
  7. johndeverill

    7 segment pressure gauge help? Modify voltmeter from Projects?

    Many thanks. Ill take a look, John
  8. johndeverill

    7 segment pressure gauge help? Modify voltmeter from Projects?

    Hi, Relating to my other post. I have a pressure transducer that outputs 0-100mV for 0-30psi. What I would like to do is create a 7 segment led (well double/triple) figure type that would display 0-30 for 0-100mV being supplied. If anyone could point me in the right direction on this one that...
  9. johndeverill

    Circuit query

    Hi Ante, Many thanks for your help. What I want the circuit to do is upon, say, 14psi being applied to the pressure transducer (46.7mV by my calculation) I want to adjust a potentiometer to vary when the transistor allows 12v to flow to the solenoid and hold it open (it is normally closed)...
  10. johndeverill

    Circuit query

    Hi, I wonder if anyone can give any advice on a circuit I want to build. I have a pressure transducer that output 0-100mV for 0-30psi. I have a solenoid that is activated by 12v. I want to control at which pressure the solenoid is activated. The circuit I imagined would be the transducer...
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