Reset is by touch. You only need to touch two plates, one near the other, to stop the alarm.
Power comes from AA cells or from a 9 V battery. When the sound is off, the current drain is very low, extending the battery life to several weeks.
Sensor wiring can be long, which is important if you want to install the transducer some distance from the swimming pool. If the distance is more than 30 feet, we recommend shielded cable for this connection.
A schematic diagram of the Swimming Pool Alarm is given in Fig. 1.
For a swimming pool alarm, sensor X1 is constructed with two common wires as shown in the figure. The wires are separated by a distance of 1 to 2 inches and stand 1/2 to 1 inch above the water.
For the rain or water alarm, a sensor is formed by two metal (copper or aluminum) screens separated by a piece of porous paper or tissue with some salt. Remember that, in this version, to reset the alarm, you have to replace the piece of paper or tissue With a dry one before acting on X2.
Correct positioning of the polarized components must be observed.
IC1 - 4093 CMOS integrated circuit
X1 - Sensor (see text)
X3 - Piezoelectric transducer or crystal earpiece
X2 - Touch sensor (see text)
S1 - SPST toggle or slide switch
B1 - 6 V or 9 V, four AA cells or battery
R1 - 4,700,000 Ω, 1/4 W, 5% resistor
R2 - 10,000,000 Ω, 1/4 W, 5% resistor
R3 - 47,000 Ω, 1/4 W, 5% resistor
C1 - 0.022 µF ceramic or metal film capacitor
C2 - 100 µF, 16 WVDC electrolytic capacitor
