PCB Heaven

General Category => Your projects => Topic started by: alb1985 on May 15, 2013, 21:37:49 PM

Title: touch sensor!
Post by: alb1985 on May 15, 2013, 21:37:49 PM
Can you explain the time base concept on your theory of touch sensor circuits.  Is it a a one shot timer or repeat timer?
I am doing something similar.
Title: Re: touch sensor!
Post by: kam on May 16, 2013, 10:56:05 AM
Its a normal "repeating" timer based on an RC delay circuit. When you touch the C, you add your capacitance in parallel, so the timer changes frequency. Your goal is to measure the frequency and detect this change