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
Computer Interface Circuits
Computer Interface Circuits
The interface circuit between single-chip accelerometer MMA1220D and microcontroller
The microcontroller within A / D converter can use PIC MCU within A / D converter produced by the Microchip. MMA1220D`s state end and self-test end are connected to the P1, P0 ports of ?C, its output voltage is sent to the A / D converter input end. C1, C2 are the power supply decoupling capacitors. A / D converter`s reference voltage side (...
DK04 Monitoring Module and Computer communication interface circuit
As shown in figure, D187 is an UART, it`sRX / TX signalconnectedonoptocoupler N21, N22 and N29, so that put the RS-485communication interface receiver / transmitter D28and microprocessor D211 completely optoelectronicisolated. D197 is a generator, the currently communication rate is 9600bit / s. D189 is another universal asynchronous receiver...
DIY computer infrared interface
A, B are 2 common contact, outline drawing and pin definition. C is the infrared emission tube shape, pin definition and schematic symbol. CD4069 is the pin definition of inverter pin, and F is the 9013 transistor shape, pin definitions and symbol..
The computer Z RS-23 serial interface current loop circuit diagram
This circuitry is used for the joggle between computer Z RS-23 serial connecting current ring and current ring circuitry, it can transform the voltage semaphore of transmission into the current semaphore with 20 mA, the biggest speed can reach 1200 bits. Light-coupled device IC3, T1 make up receiving port connecting interface circuit, T2, T3...
TV as display terminal interface circuit diagram
The interface circuit is added between computer standard video signal output terminal and TV. It can enlarge standard 1V(Peak - peak) video signal am to 3V(Peak - peak). Negative feedback circuit is composed of T1 and T2. It has a wide frequency range. The enlarge time is decided by the ratio of R1 and R2..
Computer RS-23Z serial interface current loop circuit
This circuit is used in computer RS-232 serial interface and current loop circuit interface, it can transform voltage singal into 20mA current singal, the maximum transmission rate is 1200 bits. CCD IC1, T1 form receiver interface circuit, T2, T3 constitute transmitter interface circuit. When adds +12V, T2, T3 are conduction, the current...
Visual Basic & AVR RS232 interface
On this project we will control anAVR microcontroller (MCU) via Visual Basic 6. The applications of this circuit is countless. You can make, anything you want, that needs control from a Personal Computer (PC)or from anycircuit collects data from sensors. Finally, itsends these data to Visual Basic based software by using the RS232 port. You have...
USB-Atmel Interface Cable Circuit
USB-FX2 Interface Board (USB-2.0)
USB 8bit Interface Board
The goal was to make a small USB interface board which could easily be connected to microcontroller boards. It should support USB-powered as well as externally-powered operation. External components are kept at a minimum (but there are still quite a lot of them). The board may be used as USB-powered device (externally connect pins 1 and 2 on the S
Avr Usb 500 v2 open source Atmel AVR Programmer stk500 V2 compatible USB interface
Wavenode Sensor Interface
Drum Solenoid Interface for Tap-Tempo Metronome
We added an external piezoelectric element to set on the bench top, making it easier for kids to reach. We simply soldered this external piezo element to the same pads as the Tap-Tempo Metronome`s built-in piezo element. Here`s the large piezo we used. For the drum striker, we used an electromagnetic solenoid, which consists of a coil of wire...
USB I2C Interface
This kit is based upon an original design by Jan G0BBL and provides a multi-faceted replacement for the older "Rocky" serial interface kit. The kit includes: The control of the programmable Oscillator on the V6. 3 RXTX (and the older, now retired Lite + Xtrall V8. 3 RX) kits, over a USB cable, using the I2C protocol of two serial streams (the...
Vacuum Tube Direct Interface
Requires that DC power be brought into the instrument, either through special cabling or an internal battery. Should not be done to collectible instruments if they didn`t come with onboard electronics. Conveniently implemented as a field effect transistor (FET) or bipolar junction transistor (BJT) follower, or perhaps an amplifier with modest...
PC Output Interface
The PC parallel port can be easily damaged by wiring mistakes, short circuits or the circuits you connect to it. If the parallel port is integrated into the motherboard, as is the case with most computers repairs can be expensive. You can buy inexpensive I/O card which connect to a spare slot on most motherboards, these are ideal for experimentors
R5000 Computer Interface
This circuit is a modified version of an original interface on QSL Net. It is a fully isolated interface allowing computer control of the Trio/Kenwood R5000 receiver. Separate software is needed to control the receiver. The R5000 receiver is an all-mode full featured receiver covering 30-30MHz. This receiver is now discontinued but there are still
Serial mouse interface for Commodore
This interface design comes a long way. This is in fact the first microcontroller design I`ve ever started. Somehow it kept going with me during past few years. I probably drew the first lines of the schematics diagram of the first prototype in early 1998. Later, in the middle of 1998 it became the subject of my diploma-thesis for my graduation. H
USB 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