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

Sensors / Detectors -- Main Page
 

Last Updated: December 30, 2017 02:14 PM

Circuits Designed by Dave Johnson, P.E. :

5 Volt 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 David A. Johnson P.E.-March, 2002

5v Capacitance Touch Activated Momentary Switch - This circuit is discussed in more detail in the section on Capacitance Proximity Switch Technology.  The circuit is powered from a standard +5v supply.  It has both a source and sink output that change state whenever a metal button connected to the circuit. . . Circuit by David Johnson P.E.-July, 2000

Accurate Low Capacitance Meter - The circuit measures the unknown capacitance by applying a clean 20KHz 5v peak to peak triangle signal to the capacitor.  The current routed through the capacitance is sent to a current to voltage converter.  The voltage that emerges is therefore a 20KHz square wave signal, whose amplitude is proportional to the capacitance.  The signal’s peak amplitude is rectified and filtered to produce a DC voltage. . . . Hobby Circuit designed by Dave Johnson P.E.-December, 2004

Capacitance-Type Liquid Level Monitor - This circuit was originally designed to monitor the level of liquid natural gas in a tank but it can be used to also measure almost any liquid.  Two custom insulated metal tubes form a capacitor plate.  The capacitance between the two tubes increases as the level of the liquid rises. . . Circuit by David A. Johnson P.E.-June, 2000

Low Value 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. . . Circuit 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:

5 Volt 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 David A. Johnson P.E.-March, 2002

555 Based IR Proximity Detector -  Scroll down for this project.     Sometimes you want a simple solution to a problem and you don't mind if your main controller has to do the work.  This iRPD requires the main robot processor to choose which side to look at, and requires it to "debounce" the results for reliably operation.  But, it still works really well without any complex program code. __ Designed by Dennis Clark

5v Capacitance Touch Activated Momentary Switch -  This circuit is discussed in more detail in the section on Capacitance Proximity Switch Technology.  The circuit is powered from a standard +5v supply.  it has both a source and sink output that change state whenever a metal button connected to the circuit. . . Circuit by David Johnson P.E.-July, 2000

Accurate Low Capacitance Meter -  The circuit measures the unknown capacitance by applying a clean 20KHz 5v peak to peak triangle signal to the capacitor.  The current routed through the capacitance is sent to a current to voltage converter.  The voltage that emerges is therefore a 20KHz square wave signal, whose amplitude is proportional to the capacitance.  The signal’s peak amplitude is rectified and filtered to produce a DC voltage. . . . Hobby Circuit designed by Dave Johnson P.E.-December, 2004

Analogue Capacitance Meter -  The principle of operation of this meter is based on pulse-width modulation.  Larger the capacitance, higher is the pulse-width and vice-versa.  The meter given here has one oscillator and two one-shot...__ Electronics Projects for You

Body Detector -  if someone comes within cooee it will catch 'em! __ SiliconChip

Build an Ultrasonic Proximity Detector -  Detect objects through ultrasonic sound waves. __ Contact Jameco Electronics

Build this add on Capacitance Meter -  This simple add-on capacitance meter has been specially designed to help you identify capacitors from 1p to 10u.  There has always been a problem identifying capacitors, due.   __ Designed by Collin Mitchell

Capacitance meter -  Every home constructor should own at least two pieces of test equipment: a digital (or analog) multimeter and a simple frequency counter.  Most digital multimeters can measure capacitance, but the capacitance range is rather limited __ Designed by Aren van Waarde

Capacitance meter -  Every home constructor should own at least two pieces of test equipment: a digital (or analog) multimeter and a simple frequency counter.  Most digital multimeters can measure capacitance, but the capacitance range is rather limited (in my case, from about 10pF to maximally 10 µF).  it is not possible to check the value of large capacitors with such a meter, e.g.  bipolar electrolytics in a cross-over filter, or reservoir caps in a power supply.  in my attic, I have not only a digital multimeter but also a cheap frequency counter (0...10MHz).  So I decided to build a simple tool which would allow me to check the value of large capacitors, using the frequency counter. __ Designed by Aren van Waarde

Capacitance Meter -  This project is more complex than the others described earlier.  However, when finished, you will have an instrument capable of measuring all but the largest capacitors used in radio circuits.  Unlike variable resistors, most variable capacitors are not marked with their values.  As well, the markings of capacitors from salvaged equipment often rub off __ Contact IQ Technologies

Capacitance Meter -  Operates in conjunction with a voltmeter; 1pF to 22µF in six Ranges - 9V Battery supply __ Contact Flavio Dellepiane, fladello @ tin.it

Capacitance meter (Colin Mitchell) -  This simple add-on capacitance meter has been specially designed to help you identify capacitors from 1p to 10u.   __ Contact Collin Mitchell

Capacitance Meter (Elm-chan) -  This is a simple capacitance meter which can measure capacitance value easy.  There are some measurement methods for capacitance, at one time the capacitance was measured with a impedance bridge or a dip meter.   __ Designed by The Electronic Lives Manufacturing-presented Chan

Capacitance-Type Liquid Level Monitor -  This circuit was originally designed to monitor the level of liquid natural gas in a tank but it can be used to also measure almost any liquid.  Two custom insulated metal tubes form a capacitor plate.  The capacitance between the two tubes increases as the level of the liquid rises. . . Circuit by David A. Johnson P.E.-June, 2000

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

Capacitive Sensor likes ParasitICs -  09/24/98 EDN Design Ideas:  NOTE: Contains several designs, scroll to find this one.  Stray capacitance is a common problem with capacitive sensors.  The capacitance changes within the measurement range are normally much smaller than the strays; the result is a loss of sensitivity.  Various methods are available to increase the relative sensitivity (Deltaf/f0]  frequency subtraction,  __ Circuit Design by Boris Khaykin, Candid Logic Inc, Madison Heights, MI

Capacitive Touch Switch Uses CPLD -  05/29/08  EDN Design Ideas:  Using an Altera MAX iiZ CPLD, you can implement a touch-switch decoder with no external components __ Circuit Design by Rafael Camarota, Altera, San Jose, CA

Digital Capacitance Meter -  This is a simple capacitance meter which can measure capacitance value easy.  There are some measurement methods for capacitance, at one time the capacitance was measured with a impedance bridge or a dip meter.   __ Designed by The Electronic Lives Manufacturing-presented Chan

Dual comparators stabilize proximity Detector -  02/16/98 EDN Design Ideas:  (File contains several circuits, scroll to find this one)  __ Circuit Design by Arthur Harrison, US Army Research Laboratory, Adelphi, MD, and Joseph Stern, Maxim Integrated Products, Sunnyvale, CA

Femto Capacitance Meter -  This meter measures into the low femtofarad area.  Measuring in the femto area allows the smallest capacitors to be measured with precision.  Such capacitors are commonly used to compensate for input and stray capacitance in amplifiers.  __ 

How to Recover a Pulse Signal with a Large Capacitance Load -  EDN Design Ideas:  06/22/12    Load capacitance has the potential to alter a pulse’s shape, which should be avoided for pulse-signal transmission.  Since the output signal follows with an input signal, a differential circuit can be used to detect the edge of the input signal. __ Circuit Design by Chenan Tong

Infrared beam barrier / proximity Detector -  This circuit can be used as an infrared beam barrier as well as a proximity detector.  The circuit uses the very popular Sharp IR module (Vishay module can also be used).  The pin nos.  shown in the circuit are for the Sharp & Vishay modules.  For other modules please refer to their respective datasheets.  The receiver consists of a 555 timer IC working as an oscillator at __ Contact http://www.tronicszone.com

Infrared beam barrier/ proximity sensor -  his circuit can be used as an infrared beam barrier as well as a proximity detector.  The circuit uses the very popular Sharp IR module.  The pin nos.  shown in the circuit are for the Sharp module only.  For other modules please refer to their respective datasheets __ Designed by Radioland.nt.au

Infra-red Level Detector -  Useful for liquids level detection and proximity devices; Up to 50 cm.  range, optional relay operation __ Contact Flavio Dellepiane, fladello @ tin.it

Infrared Motion Detector -  Pyroelectric infrared sensor and associated circuits detect infrared radiation from human or animal body.  General purpose motion detector with normally open relay output.16 pages.  __ Golab.com

IR Proximity Sensor -  It is the same principle in ALL infra-Red proximity sensors.  The basic idea is to send infra red light through iR-LEDs, which is then reflected by any object in front of the sensor.  Then all you have to do is to pick-up the reflected IR light.  For detecting the reflected IR light, we are going to use a very original technique: we are going to use another iR-LED, to detect the IR light that was emitted from another LED of the exact same type! This is an electrical property of Light Emitting Diodes (LEDs) which is the fact that a LED Produce a voltage difference across its leads when it is subjected to light.  As if it was a photo-cell, but with much lower output current.  __ 

Low Value 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. . . Circuit by Dave Johnson P.E.-December, 2004


Capacitance Sensors:  #'s - L      M - Z


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