I am supposed to excite the bridge circuit with 1 kHz of frequency in order to get data from it. The variable part of it would be strain gauge. Can you suggest me which oscillator circuit I should use?
It looks you are busy in finding solution for your multi- strain-gauge system. Use temperature stabilized FET based Wien-Bridge Oscillator. It would be much economical.
The DDS based solution as proposed by Tomasz is highly stable and accurate but will prove expensive. Besides the DDS circuit, you will have to add driver circuit for your 30 gauges after that.
So you have to think of the TRADE-OFF between stability and economy. Another aspect you need to consider is that if you drive from DDS, if that fails all your gauges are DOWN. Whereas with WB, you can easily make modules to replace in emergency.
Please do remain in touch in case you need any further help.
OR Contact me at prasanna(dot)waichal(@)fnu(dot)ac(dot(fj)
A stable frequency source is required to drive the bridge circuit. A stable frequency source can be constructed with high Q factor elements.
At 1 KHz, the limiting comes from an inductor, whose Q is typically 100. The stability offered by LC circuit may not be sufficient. Therefore, a crystal based oscillator is used. The crystal Q factor is in excess of 100,000.