Door Phone circuit
Posted on Feb 6, 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.....
.
A follow up Mk2 version described by EA`s Jim Rowe in the May/June/July 94 issues of EA improved...
200W Lamp Flasher is used to flash lamps, bulbs and halogen lamp to give your product that...
This LED thermometer is designed for in home use, to read temperatures between about 60 and 78...
This thermometer is capable of 0.01°C accuracy over - 50°C to +150°C. A unique trim...
Most car door switches are simply single-pole switches, with one side grounded. When the door is...
The oscillator based on IC2 is responsible for producing the sound. Its output is connected to...
I bought a Doepfer LMK3+ keyboard from a very pleasant chap in Dunedin, via TradeMe, a popular...
The quartz clocks which have dominated time-keeping for the past 20 years or so have one problem:...
Here is a simple circuit using IC LM 350, which can be used for charging 12V lead acid batteries....
Here is the circuit of an Arduino-based Panic Alarm! The wiring is very simple so that even a...
Building an LC meter for a while since I do not have a multimeter that is capable of measuring...
FIG, T is the excitation transformer, R, varistor, rectifier diodes to protect against VDii ~...
characters left: