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 Dave 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
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
Tank Water Level Indicator - A little over five years ago, before water became a "cause celebre", we published a design for a simple tank water level indicator. Now, with thousands of home water tanks being installed every year (and prompted by many requests for such a project) , we thought it time to resurrect the idea, albeit with a couple of tweaks.__ SiliconChip
Ultrasonic Water Tank Level Gauge - Do you have a tank to collect rainwater? Do you know how much water is in it? This ultrasonic tank level gauge fires an energy burst which bounces off the surface of the water ? and then a microcontroller calculates how far down the tank water level is. Clever, eh! __ SiliconChip
Versatile Water Level Controller - This simple, economical and versatile circuit switches on the motor pump when water in the overhead tank falls below the lowest level and turns it ‘off’ when the tank is full....__ Electronics Projects for You