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 sma
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ll 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: 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: 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 †’. 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 †’. The MAXQ3210 ia a powerful RISC microcontroller. This device have features and capabilities to make it compatible...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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