TT Phone Dialer
SINCLAIR is a one channel PHONE DIALER, able to send, on the commuted phone line, the alarm messages previously recorded to the NOT volatile DAST memory, to the...
Telephone FM transmiter
If you ever wondered how those phone bugs from spy movies work, here is the schematic for your very own. This simple FM transmitter uses a phone line to both po...
DQPSK Pi4DemodSync
The input and output data streams of the I and Q data channels are shown in Pi/4DQPSK System: fc=990 MHz, Data rate = 48. 6 kbits/sec. Note the delay between th...
3GPP FDD User Equipment Receiver Test
3GPPFDD_UE_RX is the test bench for 3GPP FDD user equipment receiver testing. The test bench provides a way for users to connect to an RF circuit device under t...
2-Line Intercom-Cum-Telephone Line Changeover Circuit
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Telephone Call Recorder
Today phone has become an integral part of our lives. It is the most widely used communication tool in the world. Owing to its immense popularity & widespread u...
LNB Cable Data Transceiver Circuit Schematic Diagram
This circuit was designed and used to transmit commands over LNB coaxial cable. An LNB (or LNC) is a low-noise block downconverter typically used for satellite ...
DIY mobile phone jammer Schematic Diagram
A wonderful diy gsm jammer otherwise cellular mobile phone jammer schematic diagram instead of application single taking part in GSM1900 with frequency from 193...
Switching Supply In Telephone Ring Generator
The telephone ring generator shown below generates the needed high voltage from a simple switching mode power supply (SMPS) which employs a CMOS Schmitt Trigger...
Two line intercom plus a telephone changeover switch
Two line intercom plus a telephone changeover switch. The circuit presented here can be used for connecting two telephones in parallel and also as a 2-line inte...
The Link Telephone Intercom
The Link Telephone Intercom. The Link circuitry is simple and efficient, employing just two ICs, half a dozen transistors, and a handful of garden variety compo...
Telephone line based audio muting and light on circuit
Telephone line based audio muting and light on circuit. Very often when enjoying music or watching TV at high audio level, we may not be able to hear a telephon...
Telephone Headgear
Telephone Headgear. Acompact, inexpensive and low component count telecom head- set can be constructed using two readily available transistors and a few other e...
Off line Telephone tester
Off line Telephone tester. Here is a circuit of an off-line telephone tester which does not require any telephone line for testing a telephone instrument. The c...
Multipurpose Circuit for telephone
Multipurpose Circuit for telephone. This add-on device for telephones can be connected in parallel to the telephone instrument. The circuit provides audio-visua...
Wireless Telephone Bug
Wireless Telephone Bug. Here`s a neat little project that will allow you to monitor your phone line as soon as your phone is off hook. You can use a regular FM ...
FM Telephone Bug
FM Telephone Bug. Here is a simple transmitter that when connected to a phone line, will transmit anything on that line (execpt the dial tone) to any FM radio. ...
Protection For Telephone Line Circuit
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 a...
Audio/Video to UHF TV Signal Converter (Modulator)
This is the circuit diagram of audio/video modulator. The circuit will convert an audio and video signal into a UHF TV signal. It`s desired to connect a video s...
Phone circuits
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