Intercom Circuits
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This circuit consists of two identical intercom units. Each unit contains a power supply, microphone preamplifier, audio amplifier and a Push To Talk (PTT) relay circuit. Only 2 wires are required to connect the units together. Due to the low output.... -
This version of the Link is for those who really need a good cheap intercom that will work reliably, but without access to an outside Telco line. This could be in a pre school, a hobby farm or a small workshop or factory, where external phone traffic needs.... -
A simple calling bell circuit that can be used in small offices to call the office boy using an existing intercom system. The office boy can be called from up to nine locations where extension lines are installed. The system is connected to a dedicated.... -
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.... -
Before its move offshore, I was lucky enough to be involved in developing the avionics system for the Flightship Ground Effect FS8 craft.... -
This design allows to operate two intercom stations leaving the operator free of using his/her hands in some other occupation, thus avoiding the usual push-to-talk operation mode. No complex changeover switching is required: the two units are connected.... -
This circuit was requested by an school teacher. It is a simple intercom that anyone can put together and get to work. It is based on the LM380 IC chip. T.... -
Nowadays a lot of intercom units are equipped with video cameras so that you can see as well as hear who is at the door. Unfortunately, the camera lens is.... -
From this LM386 circuits we modify is this simple Doophone intercom. you can build them. read below. In this doorphone circuit,an 8 ohm speaker is used both as.... -
The intercom schematic fulfills its tasks to provide a reliable communication line and is very simple to construct. The circuit is made up of an amplifier, two switches and two loudspeakers. If additional stations (speakers) are wished, additional switches.... -
In this intercom schematic, the 8 ohm speakers is used as microphone and listening speaker. The 10K potentiometer controls volume and the total gain can be.... -
This circuit consists of two identical intercom units. Each unit contains a power supply, microphone preamplifier, audio amplifier and a Push To Talk (PTT) relay circuit. Only 2 wires are required to connect the units together. Due to the low output.... -
Usually a single telephone is connected to a telephone line. If another telephone is required at some distance, a parallel line is taken for connecting the other telephone. In this simple parallel line operation, the main problem is loss of privacy besides.... -
This intercom box takes input from any 2-way radio (FRS, GMRS, etc), cell phone, and a stereo audio source and amplifies them for listening via a headset in your helmet. The headset is a modified Chatterbox stereo headset. The standard Chatterbox mic is.... -
This version of the Link is for those who really need a good cheap intercom that will work reliably, but without access to an outside Telco line. This could be in a pre school, a hobby farm or a small workshop or factory, where external phone traffic needs.... -
This is a great intercom circuit that can be used in many ways. It uses 22V to operate and maybe it will work at a lower voltage (you can try it). For input/output it uses a loundspeaker (20-45 Ohm) on each side.... -
This Photo Instructable shows how to use two old phones as a cheap intercom between Point A and Point B. Might be useful between the house and the sh.... -
This design allows to operate two intercom stations leaving the operator free of using his/her hands in some other occupation, thus avoiding the usual "push-to-talk" operation mode. No complex changeover switching is required: the two units are connected.... -
The Clearcom type intercom bus runs at a significantly lower level than the Sony bus, the signal to the camera operator`s headset must be boosted and the signal from the camera operator`s microphone must be attenuated. To do this a very small circuit board.... -
Using 567 IC tone decoder/detector, we can build a remote control and or intercom. This circuit can be used to control a relay, or to carry an audio signal.... -
This intercom circuit suitable for accompanying door bell. This circuit uses the speakers both as microphones and as loudspeaker. This intercom is made.... -
Nothing wrong at all with that setup IMO. I`ve an (older) Peltor FMT15 amp in my Golf. Works awesome for 2 Peltor headsets. The issue is mixing Peltor & Terraphone headsets/amps. All (3) of the cars I`ve co-driven in this year have Terraphone amps. They`ve.... -
This time it is using the IC made by National Semiconductor the LM2662M. This is a direct replacement for the MAX1044 just it is a surface mount part (so it is a lot smaller). I have also changed the main voltage regulator to the LM7805ACT, more on this.... -
This is a low-cost and simple intercom circuit design. Some intercom circuits is build by applying integrated circuits. The circuit described right here utilizes 3 certainly transistors which easy to find on the electronic store. Even a new.... -
This a two station intercom. It uses two wires to run between each intercom unit. Each is self contained with its own battery, speaker, microphone and amplifier circuit. An LM386 audio power amplifier is used. It is widely available, used a....
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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.....
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