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
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
USB Interface Circuits
USB Interface Circuits
Wireless Keylogger circuit
The Wireless Keylogger consists of two main building blocks: the transmitter, and the receiver. The actual keylogging takes place in the transmitter, which is in fact a PS/2 hardware keylogger, with a built-in 2.4 GHz wireless module. Captured keystroke data is transmitted through the radio-link in real-time, rather than getting stored. The...
AVR-P40-USB-8535 BOARD FOR AT90S8535
There are two ways to program AVR-P40-USB: with ICSP port and with JTAG port. To program via ICSP port you need serial port or parallel port AVR-ICSP programmer dongle (Olimex part # AVR-PG1B or AVR-PG2B). The serial port ICSP programmer (AVR-PG1B) works with PonyProg software by from Claudio Lanconelli and the latest release may be...
Add current boost to a USB charger
The popular USB interface can charge a portable device while transferring data. But for high-capacity batteries, the 500-mA output current of USB hosts and powered hubs greatly extends the charging time. (Unpowered USB hubs supply no more than 100 mA.) Thus, a system that accepts charging power from an ac adapter as well as the USB port is more...
USB Microphone Line Level Preamp
The computer needs at least 180 millivolts peak-to-peak and the condenser microphone in my headset produces about 20 millivolts peak-to-peak into a 2.2k load with normal speech levels. There are USB ports on the machines, so I can use that for +5 volts. After a quick look in my parts boxes, I decided to put the input jack and output plug on the...
Simplest and low cost USB AVR
This is the low cost AVR programmer using attiny2313. The schematic diagram is given below. First setup the circuit as shown. One important care taken to make fuse bit avrdude -c usbasp -p t2313 -U hfuse:w:0xdf:m -U lfuse:w:0xef:m If you use serial port to write the program , use stk200 command instead of usbasp.
The SCHAER+ programmer is a programmer for PIC18 family from a PC parallel port (LPT). It is derivated from the SCHAER programmer I used to download my projects in PIC1684. The SCHAER+ programmer should be improved to use a USB connection, without any external power supply...
Build a UPS for USB devices
Portable systems often include circuitry that derives power from an external source, such as USB. When the system disconnects from the USB supply, a battery takes over and supplies current via a dc/dc converter. A diode-OR connection (Figure 1 offers the easiest way to ensure that the supply voltage doesn`t sag during this switchover to the...
ICs Simplify Battery Charging from the USB
The charger is based on the LTC4053a standalone timer-terminated constant current/constant voltage linear charger. The LTC4053 features a thermal loop which maximizes the charging rate under all conditions by regulating the maximum die temperature. Less sophisticated linear chargers must run lower charging rates or risk overheating, thus...
Dual Current-Limiting Switch for USB
The circuit in Figure 1 uses the MIC2545A-2 and the MIC2778. The MIC2545A-2 is a programmable current limit high-side switch that is capable of having current-limit up to 2.5A.
USB 1.1 Controller
The XSV-300 board is a versatile FPGA development board providing a 300-Kgate FPGA, programmable clock oscillators, standard PC interface components (e.g. a USB-Transceiver), Flash memory, RAM and 7-segment displays.
USB-power Dual-voltage regulator
This Design Idea stems from the limited availability of IC voltage regulators that can meet key USB-power specs, coupled with the need for turn-on sequencing and rise-time control at each output. As always, for PC-related designs, minimum cost is a primary motivation. USB specs require all loads to limit inrush current to less than 100 mA plus...
USB Power Management with LTC3455
The LTC3455 seamlessly manages power flow between an AC adapter, USB cable and Li-ion battery, while complying with USB power standards, all from a 4mm ½§ 4mm QFN package. In addtion, two high efficiency synchronous buck converters generate low voltage rails which most USB-powered peripherals require.
Car PC MP3 Player
This is a computer I built for my car, its an MP3 music system but can also do other tasks. Based around a super-small sub-micro ATX motherboard from a computer known as the BookPC BKi810, I have put the motherboard, hard drive, and a 12 volt power supply in a small case that fits under the seat of my car. Total size is approximately 11 x 8 x 2...
Pic-plot2: a GPIB to USB converter
This adaptor will capture plots or prints of your GPIB instrument to your PC through the USB port. It fills the need of anybody who has a test instrument with the GPIB port and likes to get the screen dump on his PC without any GPIB card or complex software. USB Self-powered from host PC.
USB Single Cell Charger
Lithium Polymer Batteries are a very common source of power today. Many electronics gadgets have one inside, and they have some reasonable features. I've bought great batteries, with different sizes and capacities for my electronics projects. So long I'm using this batteries, coming the problem: charge them.
USB Sound Card
The core of this construction is 16-Bit Stereo Digital-To-Analog Convertor with USB interface PCM2702. PCM2702 needs only few additional parts to work. The schematic is not complex. Sound card can be powered directly from USB port (jumper W1) or from external power supply (jumper W3). PCM2702 needs two power supply 3.3V (3V-3.6V) and 5V...
USB Development Board
A little board with most of Microchip kit, but less parts then all these boards. Only the basic components to get the microcontroller up and running the Microchip USB Library examples. PIC18F14K50 is a really basic device and after some research I found what you can do and what you can not do with it: What you can do: USB HID (Human Interface...
Breadboard header for ATTiny
This handy breadboard header for ATTiny 25/45/85 microcontroller is a new design based on the original idea from Tinkerlog. Maybe the most useful feature is that it can provide power to the vertical breadboard strips while connecting all six port pins to the horizontal strips. Other features are :6-pin ISP connector (works great with USBtinyISP...
Wireless XBee Accelerometer
The present document shows step by step how to easily build an interesting pointing device: the wireless tilt mouse, that allows to control the mouse?s cursor on the PC screen through the tilt of the board itself. The analog data from a 3-D accelerometer and from two push-buttons are acquired, converted and radio transmitted by an XBee module...
USB Printer Chooser Switch
With a DPDT switch, I can switch the two data lines. I tried connecting the shields from the two computers together, the grounds two computers together, switching the D+ and D- lines with the DPDT switch, and leaving the VBus lines float, but for some reason it didn't work. The Lexmark printer seemed to need to see the +5 Volts. It had been many...
USB sound card with PCM2702
If you use great IC PCM2702 from BURR BROWN / Texas Instruments you can create a fully functional USB sound card. This sound card can be powered from USB port and has one stereo output. You don’t need to install any driver for Windows XP and Vista, because they are already inside. This is really plug and play. The core of this construction is...
USB powered LED
This is a simple LED circuit that takes power from the USB port. I needed this USB light since long time ago but, finally; I was able to build it. The circuit schematic is so simple: Just one resistor and one White LED. I did use a 10,000mcd white LED. It illuminates perfectly the keyboard of my computer. In fact; it is so bright that, I can use...
USB selector switch
To share a regional press like the USB printer, scanner etc. two computers, it is relatively easy. Just connect the two computers on a network device and say the printer as shared. This method however requires the continued operation of the computer we plugged the printer. Solution to above problem is to give the circuit that we present, and has...
LCD to USB interface
LCD2USB is a open source/open hardware project. The goal of LCD2USB is to connect HD44780 based text LCD displays to various PCs via USB. LCD2USB was meant to be cheap and to be made of easily available parts. It is therefore based on the Atmel AVR Mega8 CPU and does not require any difficult to obtain parts like separate USB controllers and the...
i2c interface to USB interface
The i2c-tiny-usb project is an open source/open hardware project. The goal of i2c-tiny-usb is to provide a cheap generic i2c interface to be attached to the usb. It is meant as a replacement for those simple and cheap printer port to i2c adapters. A USB solution has several advantages incl. the built-in power supply and a more future proof...
Acceleration sensing USB interface
The TiltStick is a small acceleration sensing device in form of a USB stick. It's using a two axis acceleration sensor to measure acceleration (caused e.g. by motion and tilt). The device is emulating a USB joystick and can thus be used in conjunction with any USB equipped host (e.g. a standard PC or the Nokia N8XX family) without any special...
USB demo board
USB AVR In-System-Programmer (ISP)
Nowadays, USBis the most popular connection connection between PC and peripherals such as AVR programmers, printers, scanners etc. For that reason I had to modify my old serial AVR In-System-Programmer (ISP) to work with USB connection. You can say, "use a USB to Serial adaptorto connect your AVR ISP with your PC". Yes, that could be a solution bu
8051 USB PROGRAMMER
The above circuit uses RS232 for interfacing with PC. It is very simple circuit & works very well with PC. Power is drawn from usb port OR needs external supply of 5V. The value of the crystal is very critical at AT89C2051 and must be 11. 0592MHz. Here AT89C2051 is loaded with firmware required for RS232 communication with PC. Assemble the...
Dual cable (serial + USB) for Nikon coolpixes
To assure that USB and serial segments are electrically isolated, we used an optocoupler (U1). The LED section of U1 is driven directly by DTR, so we should select a very sensitive optocoupler to prevent too much current flow from DTR (which is usually very limited, implementation-dependent; around 3 mA max. if we don't want to push the serial...
Connecting Nokia 3310 LCD to USB using AVR
What do you do with an old phone, a microcontroller and lots of time? You hook the old phone`s LCD screen to the computer USB of course.
i2c interface to usb interface using attiny45 microcontroller
Attach any I2C client chip (thermo sensors, AD converter, displays, relais driver, to your PC via USB quick, easy and cheap! Drivers for Linux, Windows.
Computer Interface Circuits
255W Valve RF Transmitter circuit
This transmitter of 255W is depended on the coils we put at it to work in both the middle and the short waves. The power in the antenna is 255W and includes 4 states. The first consists of the EF80 that works as a COLLPITS CLAPP oscillator. Frequency selection is done in a somewhat unusual way: Instead of the variable capacitor, it uses a...
Arduino DAC Signal Generator project
Once the circuit gets current, all variables are initialized and the loop function is continually running. Initially all LEDs are off and there is no signal at the output. By pressing the signal switch, the first light that shows the most signal is at the output and the D0-D7 terminals give the appropriate signal which, when passing from the...
Recording circuit of phone conversations using PC
This circuit is used to record telephone conversations on your landline telephone. All you will need is this small circuit and subscription of your PC. There are few times when we forget what we said or told us. So we need recording. Sometime, not many years ago, recording of this kind of conversation was done with a small tape recorder. The...
FM Micro-Transmitter Bug Surveillance Circuit
The transmitter we recommend to build is quite simple. It can even be built by a beginner. However, unlike the ease of construction and its small size, it is almost certain that it will impress you with its outstanding performance. Its autonomy is 12-15 hours, with a 9 volt battery and its range is from 100 to 300 meters depending on the...
Construction of 50Watt 8Ω two-way Hi-Fi Speakers
The presented speakers are distinguished for their small dimensions and their extraordinary sound. Our home space is often limited and prohibitive for large speakers. This limitation does not mean that we will stay without high Sound Quality. Its design is simple, low cost and is easy to construct. Speaker types are too many and are designed in...
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...
1W UHF Linear Amplifier with BLW33
This circuit is an amplifier for small transmitters operating in the UHF band, specifically in the 450-800MHz range. The amplifier works in class A and we used the well-known Philips BLW33 transistor for its manufacture. The construction, although simple, can be said to be quite critical due to the high frequency singularity. To achieve this, a...
8W Amplifier with TDA2003 circuit
Many times a small amplifier is needed to meet the needs of small spaces. This amplifier can be either mono or stereo, with this circuitry you can comfortably drive two small speakers. To build the amplifier you do not need anything but a few materials and a small power supply. The power of the amplifier, although low power, will solve many...
FM Linear Amplifier 400mW
This amplifier is intended for amplifying low signals from oscillators in the FM band. It does not have frequency regulators with variable capacitors and coils, it has a wide range and moderate power capable of driving several linear amplifiers. The whole construction is based on the two low-power 2N4427 transistors, which are designed for the...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial
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