Stud Finder

[BuffaloEngineer]

Want to make a stud finder using changes in capacitance. We have a capacitance to digital converter (CDC) from Analog - they have app notes for buttons using capacitance change as an actuator, but nothing on stud finders.

I was wondering if anyone knows what a good geometry would be for an electrode to detect capacitance change (or a good reference to use) - these chips have a Cin+, Cin-, and an excitation excitation pin in the middle. Thanks!

 

[alec_t]

What is the device code?

 

[BuffaloEngineer]

What is the device code?

That part number for the chip? The AD7153 (datasheet linked and attached).

https://www.electro-tech-online.com/custompdfs/2011/10/AD7152_7153.pdf

 

[duffy]

The geometry is usually a large conductive disk with a thin ring around it. Disk is one plate, ring in the other. I've taken apart a few stud finders, this is what they use. Some of them split the central disk into 2 "D" shapes and make a segmented cap out of it.