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Electrodeless Water Level Monitor
This system operates much like a classic float switch but without any moving parts.
The illustration shows how a system using two copper coils sealed inside a plastic
pipe, can detect the level of water outside the pipe. Whenever the water level
is lower than the upper coil, no signal is coupled between the coils. Once
calibrated, this technique might also work on the outside of a plastic water tank.
(added 7/06)
Water Flowing in Pipe Indicator -- July 6, 2009
The vibrations associated with water flowing through a pipe are picked up by an
inexpensive piezoelectric wafer. The signal from the wafer is first boosted by
a micropower transistor amplifier and then fed to an ultra low power voltage
comparator. When the vibration signal has sufficient amplitude, a FET
transistor switch is activated. Drawing only 6uA, the whole circuit is powered
by a lithium coin battery, which should power the circuit for many years....
WATER SEEPAGE ALARM
This simple circuit sounds a beeper when its electrodes detect water. A single 1.5v
N cell powers it. A small 1.5v button battery will also work.
Links to electronic circuits, electronic schematics, designs for engineers,
hobbyists, students & inventors:
12 Volt Toilet Tank Refiller - A flushing toilet is something that
most city dwellers take for granted, but it can be a luxury for those who
live away from utility water and electricity. This circuit provides
on-off pump switching for a small 12 Volt pump that is used to fill a toilet
tank from an external rain water collection cistern. The 12 Volt power comes
from a small solar power system. The cistern is located at ground level, so
the pump is required to move the water up to the toilet tank.... [G. Forrest
Cook]
Christmas Tree (or other 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
decoration-laden branches....(electronic design added 7/08)
Hot Water Tank 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….(circuit / design added 8/03)
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.... EDN is migrating links. This link is not verified. Google the "title"
EDN for new link.
Plant Moisture Meter - Stick the metal probes into a freshly watered plant
and adjust R5 for a mid-scale meter deflection. The meter will monitor the soil
wetness and the meter will indicate whether it is to moist or to dry. This
circuit uses a dual power supply which could be created by two 9 volt batteries….
[Randy Linscott's circuit]
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....(added 6/03) [Circuit designed by Rev.
Thomas Scarborough]
Rain Alarm - This circuit consumes no current until moisture is detected on
the rain plate.
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. [Radioland.nt.au]
Rain Detector (Aaron Cake) - 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. (circuit / design added 8/03)
