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2 phone Intercom circuit diagram which can be used upto 1km in outdoor using ringer
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..
Ring Indicator of Telephone Line Circuit by LM555
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..
Simple Cell Phone Jammer
A â€œCell Jammerâ€ is just way of saying â€œDirty Transmitterâ€ which happens to transmit within the Cellular Phone Bands. Reality is, the dirtier the better. T..
Cellular Phone Calling Detector Circuit Schematic
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..
Mobile Phone and iPod Battery Charger
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..
Mobile Phone Battery Charger
Small and portable unit, Can be assembled on veroboard Mobile phone chargers available in the market are quite expensive. The circuit presented here comes..
Protection For Telephone Line
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 expensive equipment such as telephones filled with electronics, fax machines, (A)DSL modems
Simple Telephone Central Project
This simple telephone switching system is designed by Dr. Mustafa Kemal PEKER for training purposes. All responsibility is belong to user. Schematic and c..
Telephone Line Indicator
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..
A telephone ringer capable of making any mains-powered device work from the ringer of your fixed line. With it, you will be able to control a high-powered siren or horn, as you like, in order to relay and amplify the low-level sound of your telephone (making it audible in a big house or in a large garden)! Alternatively, you can make a lamp...
USB Powered Mobile Phone Battery Charger
This simple circuit can give regulated 4. 7 volts for charging a mobile phone. USB outlet can give 5 volts DC at 100mA current which is sufficient for the slow charging of mobile phones. Most of the Mobile Phone batteries are rated 3. 6 volts at 1000 to 1300 mAh. These battery packs have 3 NiMh or Lithium cells having 1. 2 volt rating. Usually...
Loud ringer for phone using KA2411
This phone is loud ringing tone circuit for generating the electricity bell in the old telephone. This circuit is relatively loud. so can use to replacement the same ringer or the original telephone may be lost. We do not need a new phone. The detect ringing signal tone circuit with light and sound. It is easy to use and good quality, Do not enter
Telephone repeater circuits
The telephone repeater or The call signal peripheral circuit to the loud than the original. It`s a circuit that we design follow the request. One of my friends
Old G.P.O. Telephone
The induction coil forms part of the anti-sidetone circuit. It couples audio to the receiver, and also reduces the volume of the callers own voice in the earpiece, which would otherwise be loud compared to the incoming audio from the distant end. The original handset cord (top terminals) has a distinctly brown braid, while the line cord (bottom...
audio visual indicator for telephone circuit diagram
Many a times one needs an extra telephone ringer in an ad joining room to know if there is an incoming call. For example, if the telephone is installed in the drawing room you may need an extra ringer in the bedroom. All that needs to be done is to connect the given circuit in parallel with the existing telephone lines using twin flexible wires. T
Telephone operated remote control using PIC16F84A microcontroller
You can test the board now. For example set the DIP switch to Switch1 ON, Switch2 OFF (15 sec delay) & switch3 ON, switch4 OFF (4 rings to activate half for switching ON). If you want to switch ON relay 1 (connected to RB0 of main circuit) then you have to do the following: IMPORTANT: This circuit has been tested by me and found to work correct
telephone number display circuit diagram
The given circuit, when connected in parallel to a telephone, dis- plays the number dialled from the telephone set using the DTMF mode. This circuit can also show the number dialled from the phone of the called party. This is particularly helpful for receiving any number over the phone lines. The DTMF signal generated by the phone on dialling a nu
smart phone light circuit diagram
The circuit shown here is used to switch on a lamp when the tele- phone rings, if the ambient light is insufficient. The circuit uses only two ICs and it can be implemented very easily. A light dependent resistance (LDR), with about 5 kilo-ohms resistance in the ambient light and greather than 100 kilo-ohms in darkness, is at the heart of the circ
Telephone call meter using calculator & COB
In this circuit, a simple calculator, in conjunction with a COB (chip-on-board) from an analogue quartz clock, is used to make a telephone call meter. The calculator enables conversion of STD/ISD calls to local call equivalents and always displays current local call-meter reading. The circuit is simple and presents an elegant look, with feather-to
Cell phone charger circuit diagram FSEZ1307
This cell phone charger circuit diagram electronic project is based on the FSEZ1307 third-generation primary side regulation (PSR) PWM controller integrated circuit. The FEZ1307 cell phone charger can be used for battery chargers applications for devices like : cellular phones, cordless phones, PDA, digital cameras or for replacement of linear tr
Telephone Hold Button
The Original 2 Phone Link Design
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 multivibrator, the replacement of all relays and contact banks with optocouplers, and the additi
Phone In Use Electronics Project
Phone In Use Indicator Electronics Project using 5 resistors, 2 NPN transistors, 4 diodes and 2 light emitting diodes
Cell Phone Jammer Circuit
A beautiful diy gsm jammer or mobile cell phone jammer schematic diagram for use only in GSM1900 with frequency from 1930 MHz to 1990 MHz. The GSM1900 mobi..
Spy Phone Bug Transmitter Circuit
A very simple telephone broadcaster or transmitter which can be used to eavesdrop on a telephone conversation. The circuit can also be used as a wireless telephone amplifier. One important feature of this phone transmitter is that the circuit derives its power directly from the active telephone lines, and thus avoids use of any external ba
Cell Phone Detector aka Mobile Bug
Mobile Phone Travel Charger
Here is an ideal mobile charger using 1.5 volt pen cells to charge mobile phone while traveling. It can replenish cell phone battery three or four times in..
Spy Telephone Circuit
This FM spy telephone circuit is mounted serrial with the phone line. When is signal on the wires this transmitter will radiate airwaves thru the wires wic..
Telephone Status Indicator Circuit
This simple circuit tells you about the status of phone such as Line OK, Dialing and Call attended. It also has a lock facility to block outgoing calls keeping the incoming calls as usual. This prevents misuse of telephone. The circuit uses only a few components to do all these jobs. The circuit is directly connected to the telephone lines and no
Telephone Lamp Circuit
Here is a White LED Lamp that turns on when the telephone rings. The cool white light helps to locate the phone in darkness and also helps to note the mess..
Telephone Guard Circuit
Here is a simple circuit to protect your Telephone, EPBAX, Telephone Modem etc from lightning discharge or line spikes. It uses a safety capacitor and Gas..
Telephone Ringtone Generator Circuit
This is a simple home telephone ringtone generator circuit which is built with applying only several electronic components / parts. It generates simulated telephone ringtone and requires only DC supply with 4. 5V DC to 12V DC voltage. One may possibly use this circuit in ordinary intercom or phone-type intercom. The sound is pretty loud when this c
Telephone Ringer Circuits
Telephone Surveilance Bug Circuits
Ultrasonic distance finder circuit
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 measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
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 find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
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 circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
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 circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
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, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
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 calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
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 supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
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 circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial
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