Phone Circuits
- Page 7-
The BU8872 and BU8872FS are DTMF receiver ICs developed for use in telephone answering machines, and convert 16 different types of DTMF signals into 4-bit binary serial data. In addition to a compact 8-pin DIP BU8872 or 16-pin SSOP BU8872FS package, these.... -
As it is well known, according to power saving regulations, we need to obtain a very low power consumption during standby condition for all equipment continuously powered on the mains. For not saving version of power supply, the standby power consumption.... -
The TS4956 is a complete Audio system device with three dedicated outputs, one stereo Headphone one loudspeaker drive and one mono line for a hands-free set. The stereo Headphone is capable of delivering more than 25 mW per channel of continuous average.... -
A four channel DMX512 controlled ringer. The Mk 3 will also incoporate a ringing supply generator, and thus be reproducible by others not in posession of the BT ringing supply Number 7. The ringer is microprocessor controlled, using a Parallax Propeller.... -
This is the circuit that sparked off all the other Link Telephone Intercom designs. Originally designed back in 1996 with heavy duty relays and their contact banks, it was updated late last year with the addition of IC1 in place of a simpler transistor.... -
The circuit you are about to see is the culmination of some effort at improving the basic Link intercom design. You may think that pulse dialing is `old hat` nowadays, but the exercise of building and testing the Link `P` in this format, and understanding.... -
The normal telephone bell, at times (specially during night when one does not want to be disturbed), appears to be quite irritating. The circuit shown here converts the loud sounding bell into a soft and pleasing musical tone. The incoming ring is detected.... -
While talking to a distant subscriber on telephone, quite often we feel frustrated when the voice of the distant subscriber is so faint that it is barely intelligible. To overcome the problem, circuit of an inexpensive amplifier is presented here. It can be.... -
If you feel that somebody is tampering with your telephone line you might find this little circuit useful. It detects if there is another telephone connected to the line, if there is a short or an open line. Sound and a flashing light will tell you which is.... -
Small telephone bug. Listen telephone line on your FM receiver. It is self powered. Small part count. Circuit diagram, schematics, electronics project.... -
It signals that the phone is in use by lighting a red LED. When the phone is not in use, a green LED is lit. It needs no external power and can be connected anywhere on the phone line, even mounted inside the phone. 4. The ring voltage on a phone line is.... -
This nifty little circuit lets you record your phone conversations automatically. The device connects to the phone line, your tape recorder`s microphone input, and the recorder`s remote control jack. It senses the voltage in the phone line and begins.... -
A circuit of an off-line telephone tester which does not require any telephone line for testing a telephone instrument. The circuit is so simple that it can be easily assembled even by a novice having very little knowledge of electronics. A telephone line.... -
This FM spy telephone circuit is mounted serial with the phone line. When is signal on the wires this transmitter will radiate airwaves thru the wires which act as antenna. There is no need for batteries because it got his voltage supply from the phone.... -
The three-tone ringing integrated circuit U4076B in conjunction with a piezo transducer or loudspeaker replaces the normal electromechanical telephone bell. It is operated with the ringing current fr.... -
I want to build a 2 phone intercom which can be used upto 1km using speaker of same phone to create ring on other side please help.... -
The circuit has been designed for telephone apparatus to indicate an incoming call as it rings using an LED for visual indication. BC550 an NPN general.... -
A “Cell Jammer†is just way of saying “Dirty Transmitter†which happens to transmit within the Cellular Phone Bands. Reality is, the dirtier the better. T.... -
Flashes a LED when detecting an incoming call, Powered by one 1.5V cell This circuit was designed to detect when a call is incoming in a cellular phone (e.... -
Charge your iPod without connecting it to a computer! Using the USB port on your computer to charge your player s batteries is not always practical. What.... -
Small and portable unit, Can be assembled on veroboard Mobile phone chargers available in the market are quite expensive. The circuit presented here comes.... -
A long time ago when telephones were so simple almost nothing could go amiss from an electrical point of view, Telecom operators installed surge protection on all telephone lines exposed to storm risks. Paradoxically, now that we are hooking up delicate and.... -
This simple telephone switching system is designed by Dr. Mustafa Kemal PEKER for training purposes. All responsibility is belong to user. Schematic and c.... -
With the aid of an (old) moving coil instrument it is very little effort to make a simple voltmeter that, at a glance, indicates the status of a telephone....
Neighbour Categories
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.....
Popular Circuits
This is a simple single-zone burglar alarm circuit. Its features include automatic Exit and Entry...
An isolation transformer and a variable auto transformer, very much like a Variac. Fuse 1...
This headphone buffer is based on Greg Szekeres' MOSFET Headphone Driver. It is a robust and...
Finally I was able to control an LCD Hitachi display and a 12-key matrix keypad with only one...
This encoder uses a single contact per key keyboard and provides all other switching functions...
When VOUT is very low during start-up or a short-circuit fault on the output, the switching...
Circuit The following schematic shows the design of a Parallel Port Interface Circuit Diagram...
This circuit is similar to the "Fading Red Eyes" circuit (in the LED section) used to fade a pair...
Leo Esaki invented the tunnel diode in 1957 while working at Sony (Tokyo Tsushin Kogyo at the...
When connected to popular Stax Class 1 electrostatic headphones, the design shown in the figures...
CP2128 is a low noise, fixed frequency step-up garden DC / DC converter, in the case where the...