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Liquid Detectors / Liquid Sensors:   #'s - D       E - S       T - Z

 

Last Updated: November 22, 2021 03:00 PM

Circuits Designed by Dave Johnson, P.E. :

Electrodeless Water Level Monitor  -  This is an illustration how a laser could be used to count traffic and measure the speed of each car passing through the sensor area. . . Circuit by David Johnson P.E.,  07/09/06

 

Locate a Plastic Pipe  -  I used this circuit once to track down the location of a plastic pipe, buried underground.  It transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away . . . Hobby Circuit designed by David A. Johnson P.E.,  12/14/04

Piezoelectric Water Flowing Indicator  -  The vibrations associated with water flowing through a pipe are picked up by an inexpensive piezo wafer.  The signal from the wafer is first boosted by a micropower transistor Amplifier and then fed to an ultra low power voltage comparator . . . Hobby Circuit designed by David Johnson P.E.,  07/26/09


Plastic Pipe Finder  -  I used this circuit once to track down the location of a plastic pipe, buried underground.  It transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away. . . Circuit by David Johnson P.E.,  12/14/04

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-778-8407




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

Economical Pump Controller -  Having a reliable system to pump out a sump pit is essential as mistakes and failures can lead to serious flooding and enormous expense.  in our article Sump Pump Control System we introduced a selection of electronic solutions to the following problems __ Designed by REUK-Renewable Energy UK website

Electrodeless Water Level Monitor -  This is an illustration how a laser could be used to count traffic and measure the speed of each car passing through the sensor area. . . Circuit by David Johnson P.E.-July, 2006

Electronic Water Alarm -  Aburst water-supply hose of the washing machine, a bathroom tap that you forgot to close, or a broken aquarium wall may turn your house into a pond.  You can avoid this...__ Electronics Projects for You

Float Switch Water Level Measurement -  Find out how to use float switches in renewable energy applications.   __ Designed by REUK-Renewable Energy UK website

Fluid Depletion Sensor -  his circuit detects the absence, rather than the presence of a conductive fluid.  This requires the use of AC, rather than DC for sensing, in order to prevent an electrolytic process from corroding the electrodes.  The AC is produced by a sensor oscillator,  __ Designed by Andrew R. Morris

Fluid Level Detector -  The above circuit uses an AC-sensing signal to eliminate electrolytic corrosion on the probes.  The AC signal is rectified and used to drive Transistor T1 that drives the relay.  The relay is a 12-V type of your choice.  Transistor T1 can also be a TUP.   __ Designed by Tony van Roon  VA3AVR

Fluid Sensor & More -  it Can Detect Most Liquids and more.   __ Designed by G.L. Chemelec

Fluid-Level Detector -  The above circuit uses an AC-sensing signal to eliminate electrolytic corrosion on the probes.  The AC signal is rectified and used to drive Transistor T1 that drives the relay.  The relay is a 12-V type of your choice.  Transistor T1 can also be a TUP.   __ Designed by Tony van Roon  VA3AVR

Fuel Reserve Indicator for Vehicles -  Here is a simple circuit for monitoring the fuel level in vehicles.  it gives an audiovisual indication when the fuel level drops alarmingly below the reserve level, helping you to avoid...__ Electronics Projects for You

Homemade Water Drain Pump controller -  A hole needs to be dug at the lowest place in the cellar that have water incoming problems.  The hole is about 0.5 x 0.5 x 0.5 meter, at the bottom a large water pump is mounted.  Then the different water levels was measured, so we know how to make the sensors.   __ Designed by Thomas Scherrer OZ2CPU

Hot Water Tank Level Indicator -  The idea for this project may have come to me in a flash of inspiration, and its a very simple way to check if a fuse has blown without removing it from its holder __ Designed by Andy Collison

Inexpensive Remote Watering System -  This remotely controlled watering system is both inexpensive and easy to expand.  it is designed to operate in conjunction with a conventional watering timer and allows remote switching between nine zones.  The prototype is used in a bore system, where a deep-well pump must be started and kept running while zones are being changed.  This is necessary to minimise cycling and results in maximum pump life.  A standard portable telephone is used as the transmitter and receiver__ Learning Electronics

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

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

ISFET-sensor bias -  10-Jun-04 EDN Design Ideas:  iSFETs (ion-sensitive field-effect transistors] are useful for measuring the acidity of fluids.  Accurate measurements require that the iSFET's bias conditions (iD and VDS] be held constant while the gate is exposed to the fluid under Design by Brian Harrington, Analog Devices, Wilmington, MA

Liquid Level Alarm -  Here is a simple circuit for liquid level alarm.  it is built around two BC547 transistors (T1 and T2) and two timer 555 ICs  (IC 1 and IC 2).  Both IC 1 and IC 2...__ Electronics Projects for You

Liquid Level Receiver  -  Schematic __ Designed by Jon Fick

Liquid Level Tach Transmitter -  Schematic  __ Designed by Jon Fick

Liquid Level Transmitter/Receiver System -  designed for marine applications using raytheon's seatalk®bus. includes tachometer transmitter example although the receiver is only for liquid level (16f628)  __ Designed by Jon Fick

Liquid-Level Indicator -  The LTC2990 is used to monitor system temperatures, voltages and currents.  Through the i2C serial interface, the device can be configured to measure many combinations of internal temperature, remote temperature, remote voltage, remote current and internal VCC.  The internal 10ppm/°C reference minimizes the number of supporting __ Linear Technology/Analog Devices App Notes, Mar 16th 2011

Locate a Plastic Pipe -  I used this circuit once to track down the location of a plastic pipe, buried underground.  it transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2004

Moisture Monitor for Plants -  Over-watering and under-watering both are harmful for plants.  Roots need air as well as water.  if the soil is constantly saturated, air cannot reach the roots and they suffocate.  Also, excess...__ Electronics Projects for You

Monitor Water Seepage -  A while back I received a request from a company who needed a water seepage detector.  They wanted a device that ran on 24vac and detected water using a fully isolated circuit.  They wanted a circuit which switched off 24vac to a load when water was detected . . . Hobby Circuit designed by David A. Johnson P.E.-January, 2011

Numeric Water-Level Indicator -  Most water-level indicators for water tanks are based upon the number of LEDs that glow to indicate the corresponding level of water in the container.  Here we present a digital version...__ Electronics Projects for You

One wire bus powers water level sensor -  02/15/00 EDN Design Ideas:  remotely monitor the level of liquid water in a vessel such as a swimming pool Design by Dale Litwhiler, Lockheed Martin, Newtown, PA

One-wire bus powers water-level sensor -  02/15/00 EDN Design Ideas:  remotely monitor the level of liquid water in a vessel such as a swimming pool Design by Dale Litwhiler

Overflow Water-Tank Indicator -  Water is a vital but scarce natural resource.  To prevent water wastage, this water-tank overflow indicator comes in handy.  it gives audio as well visual alarm whenever the water tank overflows.Fig....__ Electronics Projects for You

Petrol/Diesel Level Sensor -  This sensor is particularly suitable for use in small spaces, such as the petrol tank of a motorbike.  it has the advantage of not having any moving parts, unlike a conventional sensor with a float and float arm that make it difficult to fit in a tank.  must register on this site __ Designed by Published in Elecktor July/Aug, 2010

Piezo crystal Monitors liquid level -  03/30/00 EDN Design Ideas:  The simple and inexpensive circuit in Figure 1 monitors the liquid level in a container.  The piezo crystal, carefully mounted at the bottom surface of the container, receives it activation from the 74HCT14 hex Schmitt trigger.  The.   PDF contains multiple circuits, please scroll to find this one Design by J Jayapandian, IGCAR, Tamil Nadu, India

Piezoelectric Water Flowing Indicator -  The vibrations associated with water flowing through a pipe are picked up by an inexpensive piezo wafer.  The signal from the wafer is first boosted by a micropower transistor amplifier and then fed to an ultra low power voltage comparator . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2009

Plant Moisture Monitor -  Originally intended to monitor the moisture in a potted plant, this moisture monitor really shines as a Christmas tree stand water level monitor!  A fresh Christmas tree drinks water an annoying rate and bending down under the __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Plant watering timer -  it's time to automate the watering of your garden, balcony, or that azalea in your living room!  __ Designed by Manfred Mornhinweg

Plant Watering Watcher -  This circuit is intended to signal when a plant needs water.  A LED flashes at a low rate when the ground in the flower-pot is too dry, turning off when the moisture level is increasing.  Adjusting R2 will allow the user to adapt the sensitivity of the circuit for different grounds, pots and probe types.
__ Learning Electronics

Plant Watering Watcher -  A flashing LED signals the necessity to water a plant; Very low current consumption - 3V powered circuit __ Contact Flavio Dellepiane, fladello @ tin.it

Plants Watering Watcher 2 -  IC 1D is a CMOS Schmitt trigger oscillator at about 2KHz.  it starts and continues to oscillate with a supply down to 1.24V (the lowest output voltage of my LM317 variable power supply) or less;  IC 1A is an inverter;  IC 1B is a Schmitt trigger NAND gate.  its output is low only when both inputs are at, or higher than the upper Schmitt trigger threshold voltage.  With 47 ohms or less between the probes, an input is always low, so the output is always high. __ Contact IQ Technologies

Plastic Pipe Finder -  I used this circuit once to track down the location of a plastic pipe, buried underground.  it transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away. . . Circuit by David Johnson P.E.-December, 2004

Pot Plant Power -  All plants carry an electric charge relative to the ground.  This charge is more or less constant regardless of the size of the plant a kind of background voltage" in nature.  This electric charge suffuses the entire plant, from its roots to its leaves and fruit.  it was measured between a chrome-plated pin inserted into the plant __ Designed by Rev. Thomas Scarborough

Provide ISFET-sensor bias -  10-Jun-04 EDN Design Ideas:  iSFETs (ion-sensitive field-effect transistors] are useful for measuring the acidity of fluids.  Accurate measurements require that the iSFET's bias conditions (iD and VDS] be held constant while the gate is exposed to the fluid under Design by Brian Harrington, Analog Devices, Wilmington, MA

Rain Alarm -  This circuit consumes no current until moisture is detected on the rain plate.  __ 555-Timer

Rain Alarm -  This circuit gives out an alarm when its sensor is wetted by water.  A 555 astable multivibrator is used here which gives a tone of about 1kHz upon detecting water.  The sensor when wetted by water completes the circuit and makes the 555 oscillate at about 1kHz.   __ Designed by Radioland.nt.au

Rain Alarm / Rain Detector -  This rain detector will give you a heads-up the instant it starts to rain, hopefully giving you time to close windows and bring in possessions.  The battery-powered circuit draws virtually no current when the sensor is dry and the current consumption is low when the buzzer is activated so a couple of AA cells will last a long time.  Alternately, a molded power supply with a simple voltage regulator to drop the voltage to 3 volts could be used.  The circuit is basically a handy flasher circuit that operates well on only 3 volts using ordinary silicon transistors.   __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Rain Detector -  This circuit uses a sensor made of a small piece of etched PC board and a simple SCR circuit to detect rain and sound a buzzer.  The SCR could also be used to activate a relay, turn on a lamp, or send a signal to a security system.   __ Designed by Aaron Cake

Rainwater Storage Gauge -  Not only on ecologically grounds but also economically it makes sense to collect rainwater for use in the garden and increasingly for `grey water` domestic use.  People who take rainwater collection seriously use large underground tanks for storage.  The problem now arises, how can the water level be determined without lifting the tank hatch and peering in?__ Learning Electronics

Remote Watering System -  This remotely controlled watering system is both inexpensive and easy to expand.  it is designed to operate in conjunction with a conventional watering timer and allows remote switching between nine zones.  The prototype is used in a bore system, where a deep-well pump must be started and kept running while zones are being changed.  This is necessary to minimise cycling and results in maximum pump life.  A standard portable telephone is used as the transmitter and receiver__ Learning Electronics

Shower Stopper -  The shower stopper is a project suggested by one of the readers of the Technical Library.  His request was for a circuit that would activate a solenoid to shut off the hot water to the shower after a reasonable length of time.  it seems that certain members of his household enjoy long, warm showers.  This circuit is probably sadistic!  The circuit detects when the hot water is turned on in the shower by means of a __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Simple Circuit Moisture indicator -  No circuit description, schematic only__ CdS Electronic

Simple Circuit Rain Detector -  Who needs a rain detector? How hard is it to look outside to see if it's raining? But a rain detector can come handy when you're distracted; it will save you the trouble of looking out the window every second when you want to catch the start of a rain storm, or cover some water sensitive stuff on your backyard.  The following schematics are simple, but they can give design ideas or serve as a part of a more complex circuit like a computer weather data collection system.  it all depends on your dedication, skill and expertise level__ hobbyteam @ hobby-hour.com

Simple Circuit Sump Pump Controller -  Having a reliable system to pump out a sump pit is essential as mistakes and failures can lead to serious flooding and enormous expense.  in our article Sump Pump Control System we introduced a selection of electronic solutions to the following problems __ Designed by REUK-Renewable Energy UK website

Soil Moisture Tester -  Plants seem to have something in common with pets.  They are usually acquired or given with the best intentions, but not everybody seems to be able to look after them properly.  Of course we do not expect everybody to have green fingers, but when plants are not watered enough they simply die.  in any case, too much neglect usually has fatal consequences.  Cactuses seem to survive such a careless treatment the longest and we have to admit that these are the only plants that manage to survive at our offices.   __ Designed by Popescu Marian

Sonar Water-Level Meter -  Three-fourths of the earth is water, out of which 97 per cent is saline (in oceans, seas and groundwater).  The remaining 2.5 per cent to 2.75 per cent is fresh water, ...__ Electronics Projects for You

Sump Pump Controller -  Every sump pump controller that I have seen on the web uses DC to sense the water.  This approach is simple, but eventually causes corrosion of he sensor probes due to the electrolysis.  The probes than have to be periodically cleaned or replaced.  This c __ Designed by Andrew R. Morris

Sump Pump Controller -  Having a reliable system to pump out a sump pit is essential as mistakes and failures can lead to serious flooding and enormous expense.  in our article Sump Pump Control System we introduced a selection of electronic solutions to the following problems __ Designed by REUK-Renewable Energy UK website

 

Got Designs?
Please eMail
if you want me to link to and/or post your original design Thanks.


Liquid Detectors / Liquid Sensors:   #'s - D       E - S       T - Z


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