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Sensors / Detectors: Capacitance Sensors
Capacitance Sensors:  #'s - L      M - Z

Sensors / Detectors -- Main Page
 

Last Updated: November 30, 2017 02:27 PM

Circuits Designed by Dave Johnson, P.E. :
Momentary Operation Touch Switch - This simple circuit uses a single IC to form a nice touch switch circuit.    A single transistor forms the remote active switch sensor.    Multiple switches can be wired in parallel.    The switch circuit can be located about 500 feet from the control circuit. . . Circuit by Dave Johnson P.E.-March, 2002

Precision Low Capacitance Meter - This circuit was originally designed to measure the volume of fluid inside a medical syringe.  As designed, it produces a zero to 5 volt output, corresponding to a capacitance change of about 10 picofarads . . . Hobby Circuit designed by Dave Johnson P.E.-December, 2004

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747




Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

Magnetic Proximity Switch -  Here is an interesting circuit for a magnetic proximity switch which can be used in various applications. The circuit, consists of a reed switch at its heart.  When a magnet is brought...__ Electronics Projects for You

Mains-operated Capacitive Sensor -  Easily adjustable, high sensitivity circuit; Minimum parts counting __ Contact Flavio Dellepiane, fladello @ tin.it

Measure open-circuited cables using a multimeter -  09/26/02 EDN Design Ideas:  You can use a multimeter with capacitance-measurement capability to measure the length of wire or cable to an open circuit.  The capacitance of a pair of wires (or a wire to a shield] is directly proportional to the length of the wire.  if you know the capacitance per foot of wire, then you can calculate how far it is to the open circuit __ Circuit Design by Ron Duffy, Agilent Technology, Colorado Springs, CO

Momentary Operation Touch Switch -  This simple circuit uses a single IC to form a nice touch switch circuit.    A single transistor forms the remote active switch sensor.    Multiple switches can be wired in parallel.    The switch circuit can be located about 500 feet from the control circuit. . . Circuit by Dave Johnson P.E.-March, 2002

Motion Detector Alarm -  This motion detector alarm circuit can detect a moving person from a distance of 1 meter.  it uses a Dual IR Transmitter-Receiver module HOA1405.  When the sensor detects the reflected IR rays, Alarm will sound for 2 minutes.  The circuit can be modified for various applications including AC operated alarm systems.  Motion __ Designed by D Mohankumar

Motion Detector alarm -  This motion detector alarm circuit can detect a moving person from a distance of 1 meter.  it uses a Dual IR Transmitter-Receiver module HOA1405.  When the sensor detects the reflected IR rays, Alarm will sound for 2 minutes.  The __ Designed by D. Mohankumar

Motion Sensor for Security Light -  Here is a system based on PiR motion detector module BS1600 (or BS1700) that can be used for security or corridor lighting in power-saving mode.  The 12V DC power supply required...__ Electronics Projects for You

Motion Sensor Light Switch -  3-Sep-15 -Design News:   Are there light switches in your home that aren't as conveniently located as you would like? This laser-based switch decoder and driver allows for flexible control of those lights located in less than ideal places.  I live in an apartment.  My kitchen is boring and can be accessed from either end of __  Gadget Freak-Case #272

Negative Impedance Improves Capacitive Sensor -  03/30/95 EDN Design Ideas:  You can improve a capacitive-sensor circuit with a modulator and an RF transmitter (Reference 1) by modifying the modulator portion to obtain better accuracy.  More improvements result from adding a "negatron" circuit, a configuration that uses equivalent negative capacitance.  Reference 2 gives some insight into the uses of negative impedance  __ Circuit Design by Alexander Bell, Infosoft International, Rego Park, NY

Non-Contact Human Interface Capacitive Switch -  Simple, highly sensitive capacitive ON/OFF switch pads change the state of a latch and turn on an LED without requiring actual physical human contact.  The pad may be insulated.  A range of 12mm is easily obtained and sensitivity is adjustable.  Power is supplied via a common 9V battery.  Non-Contact Proximity Switch Circuit __ Designed by Jim Keith

Person Detector -  This is a circuit thich I originally included in my book, 22 Tested Transistor Projects, published by Babani Press in 1976 (iSBN 0 900162 63 S).  it is one I had great fun with.  it uses the PUT Complimentary Feedback Pair as a sensitive detector of changing electric fields to switch on an oscillator and make a noise.  it is so sensitive that it can be difficult to get it working on a test bench because of all the electric fields, but put it on a table and leave it.   __ Designed by Richard Torrens

Precision capacitance meter -  10/22/13  EDN Design Ideas:  There's an art to capacitance measurement.  What do you think of this rendition?  __ Circuit Design by Francesc Casanellas

Precision Capacitive-Sensor Interface Suits Miniature Instruments -  24-Jul-08 EDN Design Ideas:  A pair of one-shots develops a voltage proportional to the value of a capacitive sensor and transmits these readings via a LVDS interface __ Circuit Design by Jiaqi Shen and Xiaoshu Cai, University of Shanghai for Science and Technology, Shanghai, China

Precision Low Capacitance Meter -  This circuit was originally designed to measure the volume of fluid inside a medical syringe.  As designed, it produces a zero to 5 volt output, corresponding to a capacitance change of about 10 picofarads . . . Hobby Circuit designed by Dave Johnson P.E.-December, 2004

Proximity Detector -  Here is a Simple, But Very Effective One.   __ Designed by G.L. Chemelec

Proximity Detector (uses human body capacitance) -  Schematic Only __ Designed by G.L. Chemelec

Proximity Detector with HOLD Times -  Here is a another Simple Proximity Detector, but with added Features.   __ Designed by G.L. Chemelec

Proximity Switch for 240VAC Lamps -  Just wave your hand near it to turn the light on or off.__ SiliconChip

RS-232C link Monitors animal activity -  11/06/97 EDN Design Ideas:  A common need in biological experimentation is the ability to unobtrusively monitor the activity of small caged animals, such as mice, rats, and rabbits, as they move about their enclosures.  This monitoring must be over long periods and around the clock.  The circuit in __ Circuit Design by W Stephen Woodward, University of North Carolina--Chapel Hill

Solve low-frequency-cutoff problems in capacitive sensors -  11/28/02 EDN Design Ideas:  One of the first problems a capacitive-sensor analog designer must face is the low-frequency cutoff.  Theoretically, you must fulfill just one simple requirement  a sufficiently large input resistance of the preamplifier's first stage.  in practice, however, many problems lurk behind the seemingly straightforward design rules __ Circuit Design by Julius Foit, Czech Technical University, Prague, Czech Republic

Touch Activated Alarm -  Not much to tell here as the circuit speaks for itself.  The 555 can be almost any type, they are all pin-compatible.  Although some CMOS types may not have enough power to drive the transistor, in that case use an ordinary 555.  C1's working voltage should be increased to 25V if you decide to go with a 12V power source.  Change the value of C1 for the desired output pulse __ Designed by Tony van Roon  VA3AVR

Touch-Sensitive Musical Bell with Timer -  This circuit is built around CMOS IC CD4011 and popular melody generator IC UM66. When touch plates are bridged by hand for a moment. the circuit starts to generate music. After __  01/01/07 - EFY

Wireless Temperature & Humidity Sensor with USB -  this project is based on obdev's Remote Sensor example and their firmware-only USB implementation; the main change is the replacement of the analog sensors with a Sensirion SHT11 digital temperature and humidity sensor__ 


Capacitance Sensors:  #'s - L      M - Z


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