using a scope to check signal

[William]

I would like to know were is the test point to check the decay of the transmit pulses and can they be timed? Also were is the test point for the detected signal , so you can take a look at it? I have a scope but I'm not sure what I'm looking at. These questions are for a P.I. detector. Thanks William

[david]

Re: using a scope to check signal

Hi William

The best place to view the decay curve of the transmitted pulse is pin 6 of the 1st amp,for the detected signal i would scope the dc level of the electronic switch normally a cmos 4066 or a single fet depending on the make of your detector,if you find the correct output of the electronic switch you should get a straight line on the scope which will rise and fall as you pass metal near the coil.

[Sid]

Re: using a scope to check signal

Just a little aid. Set your scope to the external synchronization and tie one end of a wire on the coil cable, the other end connect to the synchronization input. The capacitance of the wire helps to get synchronization to the colector voltage peak. Sid

[william]

Thanks David and Sid I will give it a try

Thanks I will try your suggestions. William