Advertisement
Telephone Ringer Circuit – Circuit Schematic
Telephone Ringer Circuit
The Telephone project posted here is the a telephone ringer which producespleasanttunes when a call is placed to your number. The tunes produced by telephone ri...
ray dialer – Circuit Schematic
ray dialer
RayDialer TX1 Channel Settings = Note: Switch pulls low, if ON. DIGIT 4 3 2 1 frequencies [Hz] 1 ON ON ON OFF 697 + 1209 2 ON ON OFF ON 697 + 1336 3 ON ON OFF O...
Rockwell Jupiter GPS module – Circuit Schematic
Rockwell Jupiter GPS module
The Rockwell Jupiter TU30-D140 is a OEM (Original Equipment Manufacterer) GPS receiver module that is designed to be implemented as part of a larger design, lik...
RCA CT-100 Color Television Design – Circuit Schematic
RCA CT-100 Color Television Design
If you haven`t already read my CT-100 restoration article, I suggest that you start there. It chronicles how I found a CT-100 and restored it to working conditi...
Antenna Tower Electrical Circuit Schematic Wiring Diagram – Circuit Schematic
Antenna Tower Electrical Circuit Schematic Wiring Diagram
...
Simple Telephone Ring Tone Generator Circuit schematic with explanation – Circuit Schematic
Simple Telephone Ring Tone Generator Circuit schematic with explanation
This is the figure simple telephone ring tone generator circuit designed using only a few components. It produces simulated telephone ring tone and needs only D...
The Link Telephone Intercom Every Home Should Have One! – Circuit Schematic
The Link Telephone Intercom Every Home Should Have One!
The Link circuitry is simple and efficient, employing just two ICs, half a dozen transistors, and a handful of garden variety components. It all runs on 12 volt...
Repair Notes of Ten-Tec Corsair 560 Digital Readout – Circuit Schematic
Repair Notes of Ten-Tec Corsair 560 Digital Readout
The Digital Readout of the Corsair 560 is just above the tuning knob. On this particular radio these six digits bounced around, often doubling the frequency ind...
GSM CELL PHONE JAMMER SCHEMATIC – Circuit Schematic
GSM CELL PHONE JAMMER SCHEMATIC
A wonderful diy gsm jammer or cellular mobile phone jammer schematic diagram for use only in GSM1900 with frequency from 1930 MHz to 1990 MHz. The GSM1900 cellu...
Video Master Circuit – Circuit Schematic
Video Master Circuit
The video master consists of a series of converters that place all your video sources on unused UHF channels, which then combines them with normal TV channels ...
Atv Video Sampler Circuit Circuit – Circuit Schematic
Atv Video Sampler Circuit Circuit
This unit picks up your ATV signal by sampling the transmission line with negligible insertion loss. It uses 2 N connectors for input and output connections. A...
Telephone Line Tester Circuit – Circuit Schematic
Telephone Line Tester Circuit
The telephone-line tester consists of nothing more than a meter (that`s used to measure line voltage in the on- and off-hook state), three resistors (one of wh...
Telephone Hold Circuit Circuit – Circuit Schematic
Telephone Hold Circuit Circuit
When SI is pressed, the SCR fires, and places LED1 and Rl across the phone line. The line voltage drops to about 20 V,...
Telephone Amplifier Circuit – Circuit Schematic
Telephone Amplifier Circuit
Section Ul-a is configured as a high-gain inverting voltage amplifier that is inductively coupled to the phone line via LI. Inductor LI is a homemade unit that...
Caller Id Circuit Circuit – Circuit Schematic
Caller Id Circuit Circuit
This caller ID circuit uses the Motorola MG145447 IC chip....
5V Dial Tone Circuit Circuit – Circuit Schematic
5V Dial Tone Circuit Circuit
This circuit uses inexpensive, common components to generate a precise dial tone for phone applications (see the figure). Ul (an Intel 82C54 timer-counter) gen...
Phone Pager Circuit – Circuit Schematic
Phone Pager Circuit
This pager allows you to use your in-house phone wiring as a PA system. It uses two tone decoders to detect a particular touch-tone key....
Telephone Scrambler Circuit – Circuit Schematic
Telephone Scrambler Circuit
Two hybrids (Tl and T2) are used to allow direct connection to a telephone line. This circuit uses the common speech-inversion algorithm where the frequency of...
Telephone Voice Mail Alert Circuit – Circuit Schematic
Telephone Voice Mail Alert Circuit
The cireiilt is built around a couple of low-cost ICs: an H11C4 optoisolator/coupler with an SCR output (Ul) and an LM3909 LED flasher (U2). It is connected to...
Speakerphone Adapter Circuit – Circuit Schematic
Speakerphone Adapter Circuit
Using a Motorola MC34118 speakerphone IC, this adapter can be used with a regular telephone to provide speaker capability. This device is powered from the phon...