555 IC Water Level Sensor/Detector Alarm

This schematic diagram below shows a 555 IC water level sensor/detector alarm circuit. This circuit is powered through the emitter current of the BC109C. 555 timer is used as astable oscillator in this circuit. When this circuit is under dry conditions the transistor will be fully off because it have no bias current. when the probes get wet, a small current flows between emitter and base then the transistor switches on. The 555 osillator is enabled to sound because of a larger current flows in the collector circuit. Here is the schematic diagram of the circuit:
555 IC Water Level Sensor Detector Alarm circuit schematic diagram
An On/Off switch is provided and use a non-reactive metal for the probe contacts. We can use Gold or silver plated contacts from an old relay. But, a cheap alternative is to wire alternate copper strips from a piece of veroboard. These will eventually oxidize over, but the higher impedance caused by oxidization is not important because very little current is flowing in the base circuit. the transistor is in emitter follower, so no base resistor is necessary. The current limit being the impedance at the emitter. [Circuit’s schematic diagram source: www.zen22142.zen.co.uk]

This entry was posted in Test and Measurement and tagged . Bookmark the permalink.,
Possibly Related to "555 IC Water Level Sensor/Detector Alarm" Circuits

  • Water Level Sensor/Detector/Monitor With Alarm
    This schematic diagram shows a water level sensor/detector/monitor circuit. An alarm is also featured in this circuit. Any fluid with a resistance under 900K between the maximum separation distance of the probes will trigger this circuit. A 4050B CMOS hex … Continue reading →...
  • CD4093 Water Level Sensor (Detector)
    This water level sensor (detector) circuit uses a standard NAND logic gate to produce oscillation and to detect the water level. Oscillation is included inside this circuit to provide alternating current (AC) source for probe electrodes, to achieve a corrosion … Continue reading →...
  • Water Level Sensor/Alarm System for MAXQ3210 Controller
    The MAXQ3210 ia a powerful RISC microcontroller. This device have features and capabilities to make it compatible for battery-powered applications that detect a condition and sound on alarm. Piezoelectric horn driver, 5V to 9V regulator, and analog voltage comparator support … Continue reading →...
  • LM324 Water Level Sensor/Indicator
    This is Hot Water Level Indicator circuit. This circuit can be used to monitor level of hot water in a tank. This circuit is simple and inexpensive. this circuit uses thermistors NTC1-4 as the sensor that is placed spread over … Continue reading →...
  • LM1830 Fluid/Liquid/Water Level Control
    This is Fluid/Liquid/Water Level Control circuit using LM830. The LM830 can be used to detect absence and presence of aqueous fluids. This application uses two probes and a voltage divider circuit to detect the presence of the fluid. Sometimes, there … Continue reading →...

Comments are closed.