door bell circuit
Posted on Feb 5, 2014
Related Circuits
New Circuits
-
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.....
.
The unit is simple to build, and does not need really low noise opamps, since they only act as a...
A cadmium sulfide photocell (LDR1, which is a light-dependent resistor) is connected to the base...
Transistors are used for current sources. Base drive for these transistors is derived from the...
When activated, the transmitter sends out a 49.890-MHz, AM rf carrier. The.receiver detects,...
The TV transmitter given here uses UK standard 1 FM modulation for sound and PAL for video...
One method of controlling power to ac circuits uses a triac to turn the power on and off at...
The circuit below uses two quad voltage comparators (LM339) to illuminate a series of 8 LEDs...
For those who never heard about supercapacitor, you can check for more info about supercapacitor...
This ambit is a simple two transistor (2N2222) mini FM transmitter. No authorization is...
How often on average do you have to call members of your family each day to tell them that dinner...
The amplifier of circuit, use negative current feedback. So, the load current depends mainly from...
This is a design project of an air-filter sensor to be used in home heating and cooling system....
There are 2 ways to build a protximity detector. One is mount the IR LED and the phototransistor...
Just point this small device at the TV and the remote gets jammed. The circuit is self...
Electric water heater temperature control circuit, with water level indication, temperature and...
characters left: