Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
DIY HV Variable Cap
DIY PMA alternator
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
simple intercom circuit transistor
video switch for intercom system 4060
intercom circuit using fader
This is a complete circuit that is shown in the diagram below and is formed by a microphone amplifier built around IC1A, is a design for intercom circuit. In this circuit, there are 2 IC, LM358 that is used to low power dual op amp and 4016 or 4066 Quad bilateral for switch IC. This IC that is used to control the circuit. This is the figure of the
low cost intercom
This is a design circuit for intercom circuit. The circuit comprises a 3-stage resistor-capacitor coupled amplifier. When ring button S2 is pressed, the amplifier circuit formed around transistors T1 and T2 gets converted into an asymmetrical astable multivib-rator generating ring signals. These ring signals are amplified by transistor T3 to drive
27mhz intercom walkie talkie circuit
Intercom walkie talkie are the next logical step in this discussion. They show how a crystal oscillator can be used to transmit voice. Transmitting a voice via a crystal locked oscillator is not easy. This is because the crystal is locking the frequency and it is very difficult to shift it. The only way to do it is to add the audio as an amplitude
8 line intercom using 89c51
intercom circuit with transistors
The secret to preventing instability (motor-boating) with a high gain circuit like this is to power the speaker from a separate power supply! You can connect an extra station (or two extra stations) to this circuit design. Build the circuit into two separated boxes (for 2 stations). On each box should be use 2 ports for external power supply port
An 8 ohm speaker is used both as a microphone and also an output device. The BC109C stage amplifies in common base mode, giving good voltage gain, whilst providing a low impedance input to match the speaker. Self DC bias is used allowing for variations in transistor current gain. An LM386 is used in non-inverting modeas a power amplifier to...
simple intercom circuit with
This is a 2-station simple intercom circuit build based on transistors part and using common 8R mini speakers. The speaker works as microphone and generate sound, so there is no need microphone for this intercom. The "press-to-talk" switches should have a spring-return so the intercom can never be left ON, push on switch can be used for this kind
diy intercom circuit
DIY Intercom Circuit Intercom Cable Full-duplex Intercom circuit schematic , cable on the way to the intercom circuit..
doorphone intercom circuits using la4100 la4101 la4102
simple intercom circuit for home communication
Did you know you can build your own home intercom? Read our instructions and find a circuit of a versatile home intercom system. The unit is able to communicate to as many as ten different locations or rooms discretely and incorporates a single change over switch for the required selections, instead of the age-old keypad system. And all these...
high quality intercom
A very high quality intercom, which may also be used for room monitoring..
intercom circuit using lm386 ic
The circuit mentioned here is a small easy to build Intercom circuit using one LM386 IC one 2N3904 transistor and few other components. LM386 is a very famous amplifier ICs mostly used by electronics hobbyists in audio circuits. In this circuit the 8 ohms speakers are used for both purposes one as speaker and second as microphone. The 10K variabl
A very good quality and simple intercom circuit using only three transistors. By pressing the switch S2 the circuit will generate ring signals. For making two way intercom make two identical circuits and combine them as shown in diagram 2. The current consumption of the circuit
Simple Two Way Communication Intercom Circuit Schematic diagram
Intercom or Inter communication circuit is a two directional communication system. It provides a reliable communication line and is extremely easy to implement. The circuit is prepared by an amplifier, two switches and two loudspeakers. We can extend this circuit by adding more number of speakers with the help of switches. IC LM384 works as a powe
Two way intercom circuit diagram using transistors and UM66 as ringer
A very simple intercom circuit designed based on transistors. No need for a changeover switch and you can use it just like a telephone..
Transistor intercom circuit
Here is a simple but effective intercom circuit that is based fully on transistors. The circuit is based on a three stage RC coupled amplifier. When the pushbutton S2 is pressed, the amplifier circuit wired around T1 & T2 becomes an astable multivibrator and starts producing the ringing signals. These ringing signals will be amplified by the transi
8 Line Intercommunication using 89c51s=
Privacy Telephone Intercom
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 how it all works, is well worth the effort. Not to mention all those out there who have the...
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.
High Quality Intercoms
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 impedance of the mic preamp, screened cable is not necessary and ordinary 2 core speaker cable, or
The Link A2B+1 (the Link Telephone Intercom - DTMF version)s
The Link 4+0 ?– Internal Intercoms
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 to be kept separate and protected from phone abusers and kids playing around … It follows ma
Simple Calling Bell Using an Intercom
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 extension for the office boy. Whenever someone needs the office boy`s assistance, he can
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..
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 together by means of a thin screened cable. As both microphones and loudspeakers are always i
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..
Video Switch for Intercom System
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..
Doorphone Intercom by IC LM386
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..
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...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity