I need a little help with designing a Circuit!

vesleharry · 2006-01-25T01:24:26+00:00

Hey I need a little help with designing/drawing a circuit. Can someonemake me a sketch or help me with the solution?Here is the my problem:I'm going to make a measurement system for a bridge (AC bridgecircuit). The measure-elements in the bridge can be resistive, forexample: a Pt-100-element for measuring temperature, or a strain gaugefor measuring pressure or power, or it can capacitive so that it canmeasure air humidity.The bridge is going to be driven by AC, and shall be square-,triangle-, or sinus-shaped. The frequency on the AC shall be in thearea from 400Hz - 1kHz. The reason for using AC is because we canreduce influence of the amplifiers DC-error.When the bridge is driven by AC-voltage, then of course the bridge'soutput signal will be AC. And this output signal must be demodulated.And the method I supposed use, is with Phase Sensitive Detection.Task:=B7 Make an oscillator circuit to drive/operate the bridge.=B7 Make a necessary instrumentation amplifier by using op-amps.=B7 Make a phase shift circuit.=B7 Make a demodulator.Terms:=B7 Assume that the bridge's output signal have amplitude =3D 2mV.=B7 The signal bandwidth is DC to 10Hz, -1dB with 10Hz.=B7 The measurement system shall be in the area 1.0V to 5.0V.=B7 The measurement system accuracy shall be =B10.5% of full scale.=B7 The measurement system resolution shall be 8 bits.Component:=B7 Available supply voltage is +12V, -12V and +5V.=B7 Available op-amps are uA741, OPA27, OPA177.=B7 Available voltage reference is LM336.=B7 Available voltage comparator is LM311.=B7 Available analog switch is DG413DJ.=B7 Available DA-converters are DA0808, DAC0832.Thanks in advance!

Jan 25, 2006 22 Replies

Rate this thread:

Fred Bloggs 20 years ago

I don't think so- he has a wife and a half...

Vote

John Fields 20 years ago

Fuck you, pigshit. If anyone\'s philosophy is stoicism instead of gluttonous self-indulgence, like yours is, they have to be on the dole? You and your ilk are, truly, one of the reasons why we\'re looked upon with disdain by the rest of the world.

Vote

Dirk Bruere at Neopax 20 years ago

Not quite yet, so single it is as far as my comment goes. I had one job that lasted 3 yrs at one time that paid for the house, so that's the biggest item of normal expenditure I do not have to worry about.

Dirk The Consensus:- The political party for the new millenium http://www.theconsensus.org

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required