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
Light Laser LED Circuits
Large Lcd Display Buffering Driver Circuit
Large LCD devices of 1 or more exhibit a large driving capacitance to the driver circuits. To solve this problem, the drive circuit shown (see the figure) introduces a buffer amplifier for each of the three common lines. Each amplifier can be programmed independently for a quiescent current of 10, 100, or 1000 jllA. In this application, the...
The interface circuit of dot matrix LCD display
It is shown using the MCS-51 series single-chip interface circuit 8051. Chip SED13 35 dot matrix LCD display for the controller, which can control
8 digital LCD display driver circuit
Shows 8 digital tube display driver circuit, driven by the two ICM7211A, BCD / = binary data signal is sent to the BO-B3 ICM7211A end, select the digital signal divided into two groups were sent sentenced Dl ~ D4 end.
LCD series microprocessor circuit diagram of speech synthesis
The speech synthesis circuit embedded microprocessor series, LCD drivers, clock oscillator, input and output ports, memory and multi-voice audio signal
A voltage inverter circuit
Our programmable MP3 player has an interface to an LCD with a HD44780 controller. These are alphanumeric LCDs with one to 4 lines of text and 16 to 40 characters per line. However, these LCDs (and LCDs in general) exist in two varieties: those that require a positive LC-driving voltage and those that need a negative LC-driving voltage. The H0420...
Audio Spectrum Monitor
This is an evaluation use of a small graphics LCD module. Last summer, SG12232C graphic LCD module has been sold sold for 1500 Yens from Akizuki Denshi and I bought it. However I could not find good application for the LCD module and it was going to go to junk box :-) so that I tried to use the LCD module temporary. Only displaying any still...
Build a PIC controlled DDS VFO, 0 to 6 MHz
Almost any 2x16 character LCD module with Hitachi HD44780 controller chip will work. The LCD pin numbers on the schematic are not valid for all LCD modules. Please check the actual signal names on your particular LCD module. The selected DFCW frequency offset will be added to the output frequency when the DFCW input is grounded. This input has a...
Versatile digital speedometer uses few components
A speedometer measures a wheel`s rotational speed. Unlike conventional mechanical and moving-magnet designs that use analog moving-pointer displays, the electronic speedometer in this Design Idea features a digital readout and a power-saving device that uses few components. Figure 1 shows the digital speedometer`s circuit design. An Atmel AVR...
To program some AVR microcontroller unit (MCU) you will need an AVR programmer. The better way to do that, is to buy some development kit like STK-500. This kit have the advandage to give you serial port, LCD connector, SRAM socket, 8 switches, 8 LEDs, connectrors for all of the ports of MCU and more, to one board. I sugest to beginers, to...
Embedded processor directly drives LCD
Driving a bare LCD does not necessarily require specialized interface circuitry or peripherals. This Design Idea describes an alternative drive scheme, which you can easily implement using the general-purpose outputs of a microcontroller. Many embedded-system applications need to interact with a user by displaying simple numeric or alphanumeric...
Homebuilt RS232 LCD Interface
There is enough of poorly constructed RS232 alike TTL level interfaces (+5volt) , this one generates it`s own +/- 10..11volts as RS232 specs. require , and is able to use very long cables like RS232 can , and protects computer as well , nice in funny environment like inside a "MP3 in car" setup. There is plenty of ready RS232-Lcd controllers 4...
My GPS LCD Display Project
This is a project that I started back late 2003 when I just starting to learn PIC programming. I wanted to building something that actually did somthing useful. This project is based on a PIC16F84. I actually came up with this idea and then after doing some searching I found that a few people had the same idea. But, I wanted to build my own that...
Understanding Integrating ADCs
Integrating analog-to-digital converters (ADCs) provide high resolution analog-to-digital conversions, with good noise rejection. These ADCs are ideal for digitizing low bandwidth signals, and are used in applications such as digital multi-meters and panel meters. They often include LCD or LED drivers and can be used stand alone without a...
DTMF Tone Decoder
This project displays telephone numbers decoded from tones. A microphone picks up the tones, a preamplifier boosts the signals, an SSI-202 DTMF chip decodes the tones, a Basic Stamp acts as an interface to an LCD display and also provides "RS-232" serial output. If you`d like to build your own tone decoder "from scratch", read on: You might have...
Powering White LEDs in Series or Parallel Connections
White LEDs are popular for portable equipment LCD backlights because they are less complex, less expensive, and smaller than CCFL backlights. Portable equipment like PDAs, cellphones, and digital cameras require backlights because they are converting to color LCD displays. This article discusses charge-pump and inductor step-up converter...
White LED Driver Guarantees Matching LED Brightness
White LEDs are widely used in small LCD backlight applications for simplicity, high reliability and low cost. However, due to variations in the forward voltage drop of white LEDs, matching the brightness becomes a major design consideration for multiple LED applications. Since LED brightness is proportional to current rather than voltage,...
Processor`s PWM output controls LCD/LED driver
The circuit comprises simply the PWM source, capacitor C, and resistors RD and RW. For CMOS circuits, you calculate the open-circuit output voltage as VCONT=D½§VDD, where VCONT is the control circuit`s output voltage, D is the PWM duty cycle, and VDD is the logic-supply voltage. The control circuit`s output impedance is the sum of the...
White-LED driver backlights LCD and keypad
Figure 1 shows a method for driving all the LEDs with a single driver IC from Catalyst Semiconductor (www.catsemi.com), the CAT32. Power comes from a single lithium-ion battery cell. A FET switch can independently turn off the group of six LEDs. The shutdown input, , on the CAT32 turns off all the LEDs. LED brightness is a direct function of the...
Figure 1 shows a simple, cost-effective way of providing these bias voltages. A step-up regulator, IC1, forms the heart of the circuit. This regulator switches at a constant frequency of 1 MHz and a fixed duty cycle of 70%. IC1 steps up the input voltage to 5V by storing the energy in the inductor when the internal MOSFET, M1, is on and...
Circuit tests VCOM drivers
Flat-panel LCD monitors offer excellent image quality and more compact form factor than CRTshence, their steadily increasing popularity. Unfortunately, the complexity of their manufacturing process makes LCD monitors considerably more expensive than CRTs. The amplifier that drives VCOM, the voltage on the backplane of the LCD panel, must be able...
LCD Serial Terminal
This project is a self-contained serial terminal using a PIC16F84 microcontroller chip, an inexpensive LCD character display, a keypad, and very little else. It is full-duplex, meaning keypresses cause RS-232 output, and RS-232 input makes characters appear on the LCD. If you connect the RS-232 output to the input you can see the keys as you...
Triple 300MHz Amplifiers Drive Video and LCDs
With the advent of HDTV and DVD video, there is a renewed focus on RGB and color-difference component video to maximize picture quality. LCD displays have also entered the mainstream for high-end and portable computer displays. These applications often require high speed triple amplifiers for routing and conditioning video signals. With...
Interface LCD with ease
The circuit in Figure 1 saves I/O pins. It uses an 8051 µC, and only four I/O pins (P1.0 to P1.3) drive the LCD, instead of the 11 pins other displays require. Data transfers in a serial mode through the P1.0 port of the µC. The µC interfaces to Pin 2 of IC1, a 74HCT4094 8-bit shift register. Serial data advances on every clock pulse and...
Backlight Inverter for Desktop LCD Displays
Large LCD (liquid crystal display) displays designed to replace CRTs (cathode ray tubes) in desktop computer applications are becoming available. The LCDs reduced size and power requirements allow much smaller product size, a highly desirable feature.
Circuit provides effective LCD drive
The circuit in Figure 1 is an effective driver for LCDs. The circuit comprises two main sectionsthe ICM7211 drivers (IC2 and IC3) and the YN06 display itself (IC1). The Intersil (www.intersil.com) ICM7211 is a 4-bit LCD driver that needs no external components. It contains three basic sections: a reference signal-generator circuit, an input and...
Seven-segment LCD uses two-wire interface
You can connect seven-segment LCDs using only a two-wire interface (Figure 1). The two-wire interface may be at the field-effect, direct-drive LCD or at a serial interface (such as I2C) that uses an eight-pin microcontroller. The design in Figure 1 uses an Atmel (www.atmel.com) ATtiny12 microcontroller, IC1. VCC can range from 2.7 to 5.5V.
Efficient LCD Illumination
A practical 92% efficient LCD backlight design is a classic study of compromise in a transduced electronic system. Every aspect of the design is interrelated, and the physical embodiment is an integral part of the electrical circuit. The choice and location of the lamp, wires, display housing and other items has a major effect on electrical...
LCD Backlight Controller
The circuit in Figure 1 is a dual, grounded-lamp backlight inverter that operates from an input of 9V to 24V, delivers current from 0mA to 9mA per CCFL and has a dimming ratio greater than 100:1. The LT1768 in the circuit is a 350kHz fixed frequency, current mode, pulse width modulator that provides the lamp-current control function.
Negative Voltage Load Swtich
The idea is simply to turn off the negative voltage load. Some examples:- - Bias votlages for LCD panels - RF Amplifiers - Audio Amplifiers The good thing about this design is that i can make use of the system i/o voltage to control the on/off and this is the whole idea. However, there are many many type of load switches that turn of...
LED Driver with Integrated Switches & Schottky
Linear Technologys LT®3466 is a dual step-up converter capable of driving up to 20 white LEDs with a programmable constant current. The device is also capable of driving asymmetric LED strings with independent dimming and shutdown control for multipanel LCD backlight applications.
Model Railroad OdometerCar
The Car shows the distance a train travels on a 5 digit LCD display. The distance is indicated down to 1/100th of a mile (about the length of a 50 foot car) with an accuracy of approximately plus 2 percent using a standard 33 inch freight car wheel. Simply stated, the Odometer Car counts the number of revolutions of one of the axles,...
LCD & Keypad drive
No description available.
Light Sensing Circuits
Light Dimmer 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