I am a Mechanical Engineer but doing this small project for my control system. I am working on a circuit which counts in coming pulses form a circuit with Schimmit Triggers with varying frequency as per sensor capacitor by Micro Controller.
Here is its image.
All Capacitors are 0.1uF except C1, it is sensor with values varying between 200pF to 2000pF, ALL Resistors are 10K and IC is 74HCT14.
I have found this one in a reference paper but I am unable to make it working on my own.
I have built this with 74HC14, as I was not having 74HCT14, on bread board and count pulses by arduino but it is quite unstable, varying from 2k to 15k. I wish not to use simple "Schimmit Trigger Oscillator" as It will need to ground one end of C1, for my application it not possible. I have tested my Arduino Code with simple "Schimmit Trigger Oscillator" and it gives reasonably accurate and stable result, so code is OK.
Can anybody help me with this circuit? Does this can only work with 74HCT14? If I wish to use 74HC14 then what changes are must to be made for stable result. Or any other circuit using Schimmit Trigger that can do this same job?
Here is its image.
All Capacitors are 0.1uF except C1, it is sensor with values varying between 200pF to 2000pF, ALL Resistors are 10K and IC is 74HCT14.
I have found this one in a reference paper but I am unable to make it working on my own.
I have built this with 74HC14, as I was not having 74HCT14, on bread board and count pulses by arduino but it is quite unstable, varying from 2k to 15k. I wish not to use simple "Schimmit Trigger Oscillator" as It will need to ground one end of C1, for my application it not possible. I have tested my Arduino Code with simple "Schimmit Trigger Oscillator" and it gives reasonably accurate and stable result, so code is OK.
Can anybody help me with this circuit? Does this can only work with 74HCT14? If I wish to use 74HC14 then what changes are must to be made for stable result. Or any other circuit using Schimmit Trigger that can do this same job?