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
Security Lock with keypad and LCD (PIC16F84A)
Finally I was able to control an LCD Hitachi display and a 12-key matrix keypad with only one 16F84 or 16F628. In a near future, I will be able to control a full QUERTY-type keyboard and a LCD display. The biggest improvement on this projects was the compatibility with the Microchip PIC 16F84 and the 16F628, also the 16x1 or the 8x1 LCD Hitachi...
Led Clock using PIC16F84
Using only 2 capacitors, 3 resistors, 4 seven-segment Display, 1 xtal, 2 switches n.o. and 1 Microcontroller PIC, you can build this Digital Led Clock. you can use common anode or common cathode display, just select the display type. Here is the pinout information: Pin 3 defines the display type. If you will use common cathode display, connect...
LCD digital Clock using PIC16F628
The reason why I'm using a LCD display is because it allow me to display many characters and it doesn't need to be "refreshed" as 7-segment Led displays. Also, the interface requieres less I/O pins. For this project I used a 16x1 LCD Display with 4-bits interface.
Remote IR controller
This unit provide 2 way IR communications using a numeric keypad and an LCD display. Data is sent and recieved in ASCII with no regard to what the data means to any particular device. The ASCII data still needs some form of encoding. For this I chose 10-pulse coding of 38Khz IR using a nifty 99 cent receiver chip , TSOP4838 The transmitting is...
Signal Generator 20KHz
This fucntion gernerator IC is specified to work to 20 MHz. So far, this unit works nicely to 50KHz. Since I seldom need signals higher than that, it has taken up a happy home on my workbench and further development is iffy at best. There are two basic approaches to controlling the frequency in this type of device. One way is to adjust the...
A/D converter 16Bit with LCD and PIC18F2550
The analog to digital converter (ADC) is a commonly required in most of the projects. Analog voltage measurement can be done using the ADC hardware built in together in a PIC. The picture below show a simple setup for measuring the voltage through the adjustment of the potentiometer. PIC used in this example come with a 10 bit ADC. In the...
PWM controller with PIC18f2455
The use of pulse width modulation (PWM) is common for the use of controlling power to a particular electrical device. Motor speed control, LED contrast control, power supplies are some of the example usage of PWM. 18 series PIC always come with a CCP module which is capable of generating PWM. The picture below shows an example of using the...
Timer and Interrupt
There are 4 timers in PIC18 which are timer0 to timer3. Timers are used when precise timing event need to be generated. Timers are usually used in conjunction with interrupt to keep the timing accurate. This guide will show an example of using timer0 to count a timer for every second. The circuit used for this example is the same as the circuit...
Roulette with LED Display
This circuit is a small digital ?roulette''. It is constituted by oscillator IC1, the counter IC2, the transistors Q1-7 that drive the display common cathode DSP1. The supply basically becomes from a battery 9V, but can become also from one power supply. The regulation of frequency should become in the 10HZ or little bigger, with to...
Frequency counter up to 1MHZ
The MK50398 is one modern decimal counter up/down of six tens, with control of screen LED of seven segments and flip-flop of storage. Counter it can measure additive and abstractively. The IC MK50398 is ideal for manufacture frequency counter as the particular circuit. The frequency of measurement is from 0 HZ until roughly 1MHZ.
Frequency meter 1KHz to 1MHz
This circuit is a frequency meter, low cost. It covers region 1HZ until 1MHZ. The IC1 schmitt trigger that it regulates the signal of entry and him changes in reasonable level suitable for the IC2-3-4. With the tenth pulse in the entry of IC2/1, is produced a pulse '' carry '' in the IC3/5. The same moment the IC2 causes the depiction in the...
Electronic 10 way Selector Relays
This is a circuit for alternative sources selection. It combines mechanical selection using a rotating switch S1, the electronic drive of the relays RL 1-10 and also the optical indication of the selection by the Display DSP1. The function is based on the connection of the mechanical selections into 4 Bit (BCD) code. It is managed by the proper...
The digital clock of circuit, has as base one IC, the MM5314N, in which are contained all the circuits that need. The IC1 collaborates with six Display of common anode, that are not critically as materials. You can select what dimension, you want it is enough you adapt pins their in the circuit. The display are drive by a system of polyplexis...
LCD Car Accelerometer
The circuit is drawn for measurement of acceleration from 1000 mg until + 1000 mg. It can be placed in kantra'n the car and be supplied from the sheath of electric lighter. The circuit includes one indicative LED and a screen LCD. The measurement of acceleration becomes with the use of IC from Analog Devices, the ADXL202. The particular element...
AVR LCD Microcontrolled Oscilloscope
A few months ago as I was surfing on the net, I saw an oscilloscope based on PIC18F2550 microcontroller and a KS0108 controller based graphical LCD. That was Steven Cholewiak's web site. I had never seen before so amazing microcontroller-only oscilloscope. That was realy impressive circuit, so I decided to design something like that but in C...
15 x 7 LED display with PIC16F628
This project is provided as a "prototyping project" as no PC board has been produced. The photographs show the project built on a matrix board using surface-mount components and very fine wire. The final design will require a double-sided board with plate-through holes, especially for the matrix of LEDs, but for the moment you can refer to the...
5x7 LED display schematic
Your 5x7 display is my favourite toy; the tunes and graphics in the elevator display always impress my mates! Since building the display I developed my own 400 dot matrix using a pic and the SN74154 [4bit binary to 1 of 16 demultiplexer\counter] - in place of the 4017. It works well but I still have to hook it up to my computer to change the...
Scoring Game circuit
You can play this game alone or with your friends. The circuit comprises a timer IC, two decade counters and a display driver along with a 7-segment display. The game is simple. As stated above, it is a scoring game and the competitor who scores 100 points rapidly (in short steps) is the winner. For scoring, one has the option of pressing either...
Quiz game schematic
This jam circuit can be used in quiz contests wherein any par- ticipant who presses his button (switch) before the other contestants, gets the first chance to answer a question. The circuit given here permits up to eight contestants with each one allotted a distinct number (1 to 8). The display will show the number of the contestant pressing his...
Telephone DTMF decoder Display
The given circuit, when connected in parallel to a telephone, dis- plays the number dialled from the telephone set using the DTMF mode. This circuit can also show the number dialled from the phone of the called party. This is particularly helpful for receiving any number over the phone lines. The DTMF signal generated by the phone on dialling a...
Digital Voltmeter with ICL7129ACPL A/D converter
This 4 1/2-digit DVM circuit is built around a Maxim ICL7129ACPL A/D converter and LCD driver. An ICL8069 CCZR 1.2-V band-gap reference diode is used for a voltage reference. S2a-b-c select one of four ranges up to 200 V (maximum). The meter also has a piezoelectric buzzer for continuity testing. S3 selects either DVM or continuity. Crystal 1...
Km Counter / meter circuit
This circuit measures the distance covered during a walk. Hardware is located in a small box slipped in pants' pocket and the display is conceived in the following manner: the leftmost display D2 (the most significant digit) shows 0 to 9 Km. and its dot is always on to separate Km. from hm. The rightmost display D1 (the least significant digit)...
Digital Volt and Amp Meter
The PIC Microchip Processor must be programmed before it will function as a Volt & Amp meter. There are many internet sites and PIC programmers that you can use. I used a Microchip MPLAB ICD 2 during the project. You might need to made changes to the circuit to accommodate a different type of programmer, do read the programmers instructions...
Battery capacity / Accumulator Charge Meter
The instrument used to measure battery capacity. The battery may be charged to any current in the range 0-3 A. The load current may be constant, may change over time or even break off completely. Unloading stops when the battery voltage drops below the set limit. Measuring the battery at various discharge currents, we consider the purpose for...
Digital Clock with Solar Regulator
The basic clock circuit (top schematic below) is similar to the binary clock (on another page) and uses 7 ICs to produce the 20 digital bits for 12 hour time, plus AM and PM. A standard watch crystal oscillator (32,768) is used as the time base and is divided down to 1/2 half second by the 4020 binary counter. One half of a 4013 data latch is...
Digital Clock Timer schematic
This clock timer uses a PIC16F628 microcontroller to display 3 and 1/2 digit time and control an external load. The clock includes a calendar with leap year and optional daylight savings adjustments. The timer output can be set from 1 to 59 minutes and manually switched on and off. The clock also has a correction feature that allows an...
Solar Power walkway marker Led display
These are the little lights with the stake on the bottom that you can push into the ground along your driveway or sidewalk and have the solar panel on top. The solar cell charges a AA NiCd battery during the day and at night the battery powers the LED. The circuit board in this particular model was originally designed to hold a pair of 5mm amber L
Arduino Retro Computer with SD card and LCD
Added a BASIC preprocessor made in python that allows you to write code withought line numbers and to use labels. the preprocessor adds the lines and changes the labels to line numbers. Also made an AmericanFootball BASIC game, as an example of how to use the preprocessor. Also made some small changes to the firmware, so make sure to update that t
Learn how to use 7-Segment LED Display using Arduino
7-Segment LED Display is a very useful component, but also a very confusing and difficult piece to use for beginners. It won`t be difficult once you get it working for the first time. It basically consists of 7 LEDs, (8 if include decimal point). Just like controlling a single LED, we need to connect each segment LED` to a Arduino digital pin. Here
8G—8 Dotmatrix Scrolling LED display using atmega8515
Here`s an another project, which makes an Scrolling LED display. Here 64 leds which are connected to an Matrix display. The Anodes are drived through an Driver.
How LCD Display Interface Circuit works
An LCD -liquid crystal display is an electronically-modulated optical device made up of any number of pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome. The block diagram shows the LCD gets a data source from the application processor, so therefore LCD is bei
Digital to Analog Circuits
Analog to Digital Circuits
Data Logging Circuits
Data Bus 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...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial