Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Piezoelectric-Noise problem due to cable

#32986

Piezoelectric-Noise problem due to cable | 2 March, 2005

Hello, We are using a film piezo electric sensor to deduct and measure vibrations. A long twisted pair shielded cable is used to connect the sensor to the signal conditioning unit (the signal conditioning unit has to be kept at a distance from the sensor). We are not able to measure the sensor signal because of the noise effect. The vibration signal is very much less when compared to the cable signal that we can detect the changes due to capacitive effect caused by the people moving near and around the setup. We tried using a high impedance Instrumentation amplifier and also a Charge Amplifier to reduce the noise. These were the two methods I got from literature as solutions to this problem, but it did not help us. Please let me know if anyone has faced a similar problem and was able to overcome it.

Sincerely,Prabhu

reply »

Dilbert

#32997

Piezoelectric-Noise problem due to cable | 2 March, 2005

You probably are aware of this, but somehow get the conditioning unit as close to the sensor as you can. It sounds like the problem is the "long twisted pair shielded cable". Try different means of shielding, connect the shield at the end that has the source of the noise only, connect the shield at both ends, connect at the other end only....

reply »

#33002

Piezoelectric-Noise problem due to cable | 2 March, 2005

But our requirement is that the conditioning unit has to be kept at a distance from the sensor. Is there any compensation circuit available to reduce the noise effect?

reply »

Dilbert

#33005

Piezoelectric-Noise problem due to cable | 2 March, 2005

You can contact the manufacturer of the sensor, I don't think they would have anything but they may be able to give you some advice. Can you route the cable a different path away from other cables or objects creating noise?

reply »

Non-heated dispensing system

Reflow Oven