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 pee
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ring in One solution is to use float switches mounted at different heights in the water tank, and to use a row of LEDs mounted remotely to show the water level in the tank. Transferring this information to a remote display will involve long cable runs so it is of interest to reduce the number of cables to a minimum. The circuit here shows how information about the water level in a tank can be sent over two wires to a remote LED display. R1 together with the resistor chain made up of R2-R6 form a voltage divider,‚oat switches are wired across the resistors R2-R6 in one arm of the voltage divider. As water flows into the tank and the level rises, switch S5 closes followed by S4, etc. Each time a switch closes, it will short out its parallel resistor in the chain thereby changing the output voltage of the divider. When the tank is full, allve switches will be closed and all the LEDs will be on. The voltage output from this divider chain is applied to the inputs of five op amps that are configured as comparators. A voltage chain comprising R7-R12 supplies the reference voltage for each of the five comparators. Both divider chains use the same supply so they will be insensitive to supply‚uctuations. The maximum supply current for the circuit is less than 25mA. Some of the resistors chosen to make up the voltage dividers are not standard values but can be easily made up from combinations of 10k and 100k resistors. If you need to...
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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