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8051 / 8052
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H Bridge Circuit
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4 Band Resistor
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Stereo power audio amplifier circuit tda2009 10+10 watts
preamplifier stereo tda1524a bass treble schematic
Wideband DTV UHF Antenna TV Amplifier Circuit using transistor 2sc3358
This HD TV UHF wideband amplifier (Ultra High Frequency amplifier ) has a total gain of 10 to 15 dB in the 400 850 MHz domain frequency so it can be used where the tv signal is weak. For this UHF antenna tv amplifier to work correctly you need to cut the components pins as short as possible. C1, C2, C6, C7 are SMD type ( surface mounted ). Thi
Circuit of graphic equalizer of 7 bands using it integrated la3607 of Sanyo
The circuit integrated la3607 allows to just set up a graphic equalizer of 7 bands for a channel adding some capacitors and variable resistors to the circuit. The cut frequency can be adjusted using variable resistors. It possesses high stability for loads capacitive. To be necessary of more channels is to set up how many units they are only neces
fm stereo transmitter ba1404 diagram
Circuit FM transmitter for MP3 and MP4 Player 2n2218 and 741 opamp
Evolution FM transmitter with 2n2218 with audio amplification step using LM741 op amp with audio input for MP3, MP4, mobile, computer and other audio sources, beyond the traditional electret microphone. With great sensitivity to the input signal. Using fewer components and easy assembly makes it ideal for those who want even without much experienc
Circuit audio pre-amplifier integrated circuit LM358 dual op amp
The LM358 series consists of two independent, high gain, internally frequency compensated operational amplifiers which were designed specifically to operate from a single power supply over a wide range of voltages. Operation from split power supplies is also possible and the low power supply current drain is independent of the magnitude of the pow
circuit to test servo motor (pole rotor) of parabolic antenna
That circuit is to test the motor servant of the parabolic antenna it is working perfectly, although a system with lnbf is much more appropriate, a lot of people they still use systems using lnb and servo motor. Then the idea of that circuit is to help to the technician reparation of parabolic antennas when doing test of operation of the servo mot
Dimmer circuit Triac TIC 226
fake car alarm 555 led flash schematic
Module thermometer temperature meter for digital multimeter using the ic lm35
Converser of temperature tension. To be used with a digital multimeter with reach from -40 °C to 110 °C. With checker of the state of it laughed and a without any adjustment, thanks to LM35! The ice is founded the 0 °C and the point of ebullition of the water, at sea level it is of 100 °C. Using those two point of reference is gauged the temperatu
Circuit Power transmitter of communitarian wireless TV lm1889 audio and video
This small circuit transmitter processes the signs of audio of a sound table or microphone, and the signs of video of a camera, or still the audio signs and video of a DVD, Video-cassette or even it sweats her video plate has an exit of composed video, you can transmit direct of your computer. Playing them in a channel free from the strip of VHF.
Circuit of power fm transmitter transistor 2n2218 audio wireless 1KM
This small transmitter can arrive the more than 1 km in favorable conditions of emission. The modulation can be made so much with a microphone, for an electrets microphone, or other audio source. The 5 turns of enameled thread 22 AWG, with diameter of 1 cm without nucleus. Look at the capacitors that it should be ceramic. The antenna should posses
shadow sensor circuit ldr circuit
TV remote control Blocker Circuit Jammer using Ic 555 and IR Leds
Just point this small device at the TV and the remote gets jammed. The circuit is self explanatory. 555 is wired as an astable multivibrator for a frequency of nearly 38 kHz. This is the frequency at which most of the modern TVs receive the IR beam. The transistor acts as a current source supplying roughly 25mA to the infra red LEDs. To increase...
Download NL5 Non-Linear Electronic Circuit Simulator
Since then NL has evolved into the Microsoft Windows ®-based NL4, which has been used extensively by world-class engineers in different fields of electronics for almost 10 years. NL5 is the first version to be publicly available. Unlike conventional SPICE-based simulators, which pretend to perform accurate simulation of electronic circuits using...
Enclosure for the Magnetometer v2.0
The magnetometer was moved to an outdoor location and a specialized enclosure was built. An accessory temperature controller was included to maintain a constant temperature and digital link was created to ferry the recorded data back into the laboratory. During the August-September 2000 refurbishment, the magnetometer was moved from the...
baby Tesla coil
Inverter circuit to power EL backlights and fluorescent tubes, so the output is about 127 VAC as he claimed. But I want 1kV or more to make at least 1mm purple plasma as Tesla coil usually produce! (30kV is required to make 1cm length plasma). Therefore i use MOSFET IRF 840 as a transistor for high switching rate (also any IRF-named MOSFET will...
In the voltage to time conversion section, the analog input voltage is fed to the attenuation circuit. The attenuated signal is compared with the the ramp signal generated by the ramp generator given in the block diagram by the input comparator `C1`. Similarly, The ramp signal generated is compared with 0V via a zero-crossing detector `C2`. A...
When a GATE signal (between 3V and 15V), the capacitor C5 acts as a differenciator and converts the gate signal into a brief positive pulse (width 10 ms). D1 protects the circuit from negative voltages. The brief pulse created on the rising edge of the GATE signal make Q1 briefly conductive and the voltage at its collecto
very simple VCA circuit
Trimming is quite easy if you use matched NPNs for Q1 and Q2, and 1% tolerance resistors for R6 to R11. You will need a dual trace scope, a DVM and a sinewave generator. Using 10 turn trimmers is a little bit more expensive than using 1 turn but makes it easier to adjust with high accuracy. Adjust the trimmer A1 in order to have a perfectly
I needed an excuse to use the soldering iron so I figured that I might as well as make a frequency counter which is something that I`ve always wanted, but lacked in my lab. Here`s the schematic. I drew it up in OrCAD PSpice a while back. Since then, I have lost the design files, but fortunately, I kept a hard copy, complete with annotations of...
DC Motor Controller and Tachometer
Controlling the speed of a motor is very important in many situations especially in robotics. There are many techniques of controlling the speed of motors, each with their advantages and disadvantages. This document will show you how to build a motor controller which controls the speed of a motor by varying the input voltage. Along the same lines,
For the purpose of this project, digital signals can be communicated with computers while analog signals can`t. RS232 is the name given to your serial port. At the back of your computer, there`s many ports where you can plug things into. The RS232 port has 9 pins and looks like: At the heart of most digital oscilloscopes is a device (usually a...
Designing your own gear
Fly back transformers are commonly found in television sets and can put out 50, 000 volts, enough power to lift a 350 pound man up and throw him back 10-20 feet killing him instantly. Also the component`s are picky sometimes and reversing the polarity (positive in the negative and negative in the positive can break the component) a capacitor...
iphone battery pack
How to create a Battery pack for your Apple device that is powered by normal Alkaline batteries. This will be a general overview of building the circuit for the battery pack and the detailed instructions for the case will be given in part 2 of this post. NOTE: When soldering the USB socket, face the open part to the right with the connector pins...
SDR TX 50MHz
Making 90 degree phase shift on VHF. This IQ Oscillator is easy way with two logic IC`s. 74AC04 inverter is used as oscillate circuit. C5 and R6 is phase shifter. 74HC14 has a duty to convert into square-wave. It is usualy used 74HCU04 in crystal oscillator circuit. Buffer of 74AC04 cause parasitic oscillation. So I teste
LED Dance Pad
Using LEDs as light sensors. A DDR pad. We designed our pad to have no moving parts. Instead, we chose to measure light reflectance off the user`s feet to determine if one of the arrows was being stepped on or not. Since a design with no moving parts offers little to no tactile feedback, we wanted to make sure the pad offered some other form of...
DIY Circuit Car Battery Charger
This very simple circuit uses a transformer, two diodes, a capacitor and an ammeter. To charge a battery just connect the + and terminals of the circuit to the corresponding terminals of the battery. When the battery is not charged, the ammeter reading shows 1-3 amps. When the battery is fully charged the ammeter reads Zero or nearly zero, af
DIY Dual Fan Controller Project
Here`s a nice little circuit diagram for all those hardcore DIYers if you are trying to build a dual fan controller using an ATtiny45 although I`d never use this thing, I`d rather use a CUBLOC. Over the course of a weekend, I cobbled together some leftover robot parts to create a simple dual-fan controller. The board turns on the first fan when t
Pulsed Argon and/or Krypton (Ar/Kr) Ion Laser
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