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
GSM modem circuit with Wavecom WMOi3
Modems are devices that connect either remote devices to a computer, or two or more computers to each other. Their connection is usually wired. The GSM modem we present is wireless. It can connect two computers, a computer with the internet or even be the central unit for a data acquisition system. Generally the construction is a GSM phone...
Modem shutdown Indicator
The circuit has been designed to accommodate all those who dedicate many hours of their lives by exploring the endless pages of this site. Despite the fact that it consists of only three components (Most were not little!), Is able to provide an indication of whether it actually released the telephone line after a long connection via modem to the...
WA4DSY 56KB RF Modem
This is a prototype of the WA4DSY 56KB RF modem. It is intended for use on amateur packet radio networks. The modem generates RF in the 28 to 30 mhz range and requires and linear transverter to convert the signal to a UHF or microwave ham band. The digital interface is synchronous serial. The modem supplies TX and RX clocks. For more details see...
LT1886: Low Distortion Line Driver
The LT1886 is a high speed dual power amplifier with excellent high frequency distortion performance. The LT1886 features a 700MHz gain-bandwidth product, 200V/ms slew rate and over 200mA of output current drive in a small SO-8 package. Using only a single 12V supply, the LT1886 is the best choice for the line driver in ADSL CPE modems...
Modem based on PIC16C620
No description available.
Connect a modem to a Basic Stamp
The 2400-bps modem in Figure 1 makes it easy to connect a Basic Stamp (Parallax Inc, www.parallaxinc.com) to a telephone modem. Using this circuit, you can call home via your PC and find out if the house is still there. The Basic Stamp2, BS2-IC, has the necessary programming space, and a 64-kbyte StampMEM memory-storage board enhances site data...
1. Because there is no DTR wire (modem pin 20) from Pilot. Pilot can simulate DTR line but this is not used at this moment (needs a pull-up) 2. This way we can not dial without a known dial tone if needed (like in some areas out of USA) 3. There no reason for this setting. Using X4 modem will dial as soon as it detects a known dial tone....
autodetects baud rate circuit MAX202 and PIC16C54
The popularity and easy access of RS-232 ports lend them to many communication projects. You can use a port as is” or as a tiny parallel port when the exchange uses only control lines. Before the asynchronous serial-data transfer between two devices can take place, you must ensure that both devices are configured to the same data format and...
Packet Radio with AVR
Here is some experimental hardware and software to transmit and receive AX.25 packets. It is essentially a PIC-E clone designed around a Atmel AT90S2313 with a few extra bells and whistles. I had picked up a couple of MXCOM MX-614s at the TAPR display (I also joined TAPR) at the Dayton Hamvention, and I needed a project to try them out on. I...
RS232 cable modem
First of all you have to build one cable adapter to connect the female 9pins connector of the modem, with female 9pins connector of the base of E-10G HPC. To build the null modem cable you will need: 2 male connectors with 9 pins. 15cm cable with 7 wires. The schematic at the left , its show how to connect the wires. When you finish it, you can...
Ac power and rectifier circuit modem chassis and power supply
Sending SMS in PDU Mode though GSM modem connected with PC Serial Port and operated with PIC Microcontroller model in Proteus VSM
IP phone to analog phone or modem audio interface circuit
The transformer is a 600:600 ohms transformer (also named 1:1 ratio 600 ohm transformer) : more or less the same number of turns on both primary and secondary coils, and optimized to work at 600 ohms load. Selectronic sells one here. I measured the primary and secondary coils on the one from Selectronic: about 75 mH inductance and 50 ohms
LM1893 for Power Line Modem Circuit
This design circuit is shows an LM1893 power line modem circuit. This circuit is used to transfer information between remote locations by using the power mains. This circuit uses LM1893 that is used as a power line interface for half-duplex (bi-directional) communication of serial bit stream of virtually any coding. This is the figure of the circu
KD2BD Pacsat Modem
The KD2BD Pacsat Modem is a low cost, high performance 1200 bps BPSK modem designed to interface between a packet radio terminal node controller (TNC) and an amateur satellite ground station, and allows full-duplex access to the 1200 baud "Pacsat" constellation of amateur satellites. The KD2BD Pacsat Modem consists of a 1200 bit per second BPSK de
300 baud modem circuit schematic
BayComm packet modem
Be sure to use the correct 9-pin `D` type connector so the pins fit in the board. The two outer holes for mounting the 9-pin `D` type connector should be 3mm Dia. and the holes for the pins are 1. 2mm Dia. The PCB is also tailored for a PCB mounting 5-pin DIN socket. These holes should also be 1. 2mm Dia. All other holes on the PCB are 0. 9mm...
acoustic modem circuit diagrams
rf modem robotics project using pic16f84 microcontroller
RF is just way too cool not to use in your designs. But if you`re a newbie like me it is difficult to successfully build solid RF transmitters and receiver..
lm1893 power line modem circuit
This is a circuit for an LM1893 power line modem circuit. This circuit is used to transfer information between remote location by using the power mains. This circuit uses LM1893 that is used as a power line interface for half-duplex (bi-directional) communication of serial bit stream of virtually any coding. This is the figure of the circuit; To g
new modem ups circuit diagram
CMX469A 1200/2400/4800 Baud FFSK/MSK Modem
CMX7031Q1 is a sub package of CMX7031, If you need see the description, please click CMX7031. If you need CMX7031Q1`s datasheet, please download it from below. By Consumer Microcircuits Limited
CMX866 V.22 Bis Modem With AT Commands
The CMX867A is a multi-standard modem for use in telephone based information and telemetry systems. Control of the device is via a simple high speed serial bus, compatible with most types of C serial Interface The data transmitted and received by the modem is also transferred over the same serial bus. On-chip programmable Tx and Rx USARTs meeting
CMX867A Low Power V.22 Modem
This RS-232 RS-232 /a> to RS-485 protocol converter uses two products for a complete operational system. The circuit will comply with all EIA and ITU specifications for RS-232 RS-232 /a> to RS-485 RS422 conversion. This is a rugged design that will handle +/-15kV ESD levels on the bus pins. The design is compatible with 3. 3V or 5V systems requirin
FX919A 4-Level FSK Modem Data Pump
This application note describes the operation and features of the FAN7601. This device is a BCDMOS programmable frequency current mode PWM Controller which is designed for off-line adapter applications and auxiliary power supplies. To reduce power loss at light and no load, the FAN7601 operates in burst mode and it includes a start-up Switch to re
Ncp1027: 16 W 12 Vdc Modem Power Supply
The NCP5080 product is a high voltage boost driver dedicated to the Xenon power flashes. The built-in DC/DC converter is based on a flyback structure with an external transformer to adapt any range of high voltage demand. The external feedback network makes possible to dynamically adjust the output voltage.
Usb-powered Dsl Modem Supply
Energy losses in modem
As transformer a toroidal transformer (2x12V 15VA) is used, because this gives much less energy losses then an E-I core transformer as used in the original mains adaptor (for more info, click here ).
Dtmf detection in GSM modem
Doing a project on GSM. In that i want to detect the key pressed at the other side on active call. I am trying with a dtmf decoder circuit at speaker output but it is not working. Plz if any one has any other idea or solution plz reply.
How To Connect Two Computers Using Modems
Have you ever connected two PCs together via modems using a twisted pair cable and nothing happened? That s because the modems are expecting a phone line..
USB Interface Circuits
Computer Interface 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