Electronic phone bell
Posted on Sep 15, 2012
New Circuits
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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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This circuit is for a QRP (low power) antenna tuner, a.k.a. a transmatch, for use in the short...
This circuit consists of twin-T sine-wave oscillators. Each oscillator has a filter in the...
This simple adapter uses an oscillator (567) to drive a counter (U2) and switch (U3) that...
100 W output at 50 MHz is available from this circuit. Ul and Q2 form a T-R relay driver,...
The cireiilt is built around a couple of low-cost ICs: an H11C4 optoisolator/coupler with an SCR...
The 555 frequency can be varied via adjusting the voltage at pin 5. However, the range and...
Figure 1 shows the 10. 58 to 10. 74 MHz VFO oscillator circuit. Yes, this is the same circuit...
Normally home appliances are controlled by means of switches, sensors, etc. However, physical...
This circuit enables any infrared (IR) remote control to control the outputs of a 4017 decade...
It is impossible to imagine present day society without any batteries. Count the number of...
This web page describes how to install and use my ezlog data logging software. This software...
D1, D2, C1, and C2 double the AC line in, charging C3 through R1 to approximately 320 volts. R1...
D amplifier uses a series fool manifold. Can easily organize a mono OTL or OCL audio power...
Use fluorescent starter bimetal can be prepared as a temperature sensing element, as the...
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