Repository-circuits
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I am using this Class A Amplifier with a 12AU7 based valve preamp. It produces the most purest sound. I have no idea of distortion levels etc. but it has a very fine grain and delicately textured quality. With only one watt of output efficient speakers must.... -
The power line fluctuations and cut-offs cause damages to electrical appliances connected to the line. It is more serious in the case of domestic appliances like fridge and air conditioners. If a fridge is operated on low voltage, excessive current flows.... -
This includes a 220uF capacitor and two diodes to slow down the switch-on to reduce the output thump as the output capacitor charges through the speaker. This is not essential, depending on speaker sensitivity, with my own speakers there is just an.... -
Many of us have a pair of headphones connected to the output of the computer sound card us either to enjoy songs, or a game. Very likely your headphones and microphone, which also connect to the appropriate slot your sound card. But at some point broke down.... -
This clock timer uses a PIC16F628 microcontroller to display 3 and 1/2 digit time and control an external load. It can be programmed to time from 1 to 59 minutes. The clock includes a calendar with leap year and optional daylight savings adjustments. The.... -
We created an RC Car that can identify a parking space and parallel park by itself. The RC Car drives down a street searching for a parking space to its right using a distance sensor. When the car has identified a space, the car checks to see whether that.... -
The MOSFET input of the CA3140 makes it ideally suited for use in a high impedance DC voltmeter. Switch S1 is the range selector. The input impedance is limited to 10M by the resistors used in the voltage divider, but this is still a very acceptable value..... -
This circuit is a wireless car alarm system that is built using two circuit modules, namely modules of transmitter and receiver modules. This circuit works on FM radio waves. Car alarms can be used on vehicles that have a 6-12VDC power supply. You can use.... -
This is the circuit diagram of a voice operated relay. It similar with sound activation switch circuit which will turn on and turn off (connect and disconnect) the switch depending on the sound input. The output switch of this circuit is act by a relay. You.... -
This is extremely simple to build PIC Temperature meter that allows to measure temperature in two different locations at the same time. Never before such a useful and powerful circuit could be built with so little components and yet provide endless.... -
This electronic circuit uses a 555 timer as the bases of the touch switch. You can learn more about 555 timers in the Learning section on my site. When the plate is touched the 555 timer is triggered and the output on pin 3 goes high turning on the LED and.... -
The ESR Meter is basically an AC Ohmmeter with special scales and protective circuitry. It provides a continuous reading of series resistance in electrolytic capacitors. It operates at 100 kHz to keep the capacitive reactance factor near zero. The remaining.... -
This circuit is for a temperature controlled constant current battery charger. It works with NICD, NIMH, and other rechargeable cells. The circuit works on the principle that most rechargeable batteries show an increase in temperature when the cells becomes.... -
Building a serial voltage meter to measure from 0 to 5 volts DC is actually pretty easy. Using MeLabs PicBasic, and Microsoft`s Visual Basic Version 5 Pro. You need Visual Basic Pro version because you will have to use Basic`s MSComm control. This control is.... -
The FM transmitter is relatively simple to build and with only one adjustment it is ideal for the absolute beginner. But before I continue, let me just make one thing clear. With Wide-Band deviation, the VCO is never locked in phase, only in frequency. It.... -
Here`s schematics for infared remotes. This remote transmits a tone using an infared LED. This tone is decoded by the receiver. Since the receiver only switches when it "hears" the tone, there are no accidental activations. .. -
The above circuit will charge any 2-cell * Li-Ion battery pack. Maximum current is about 650 milliamps. The circuit is designed for batteries of 900mah or higher. Note this circuit is NOT for Li-Metal batts (i. e. Duralites). Power source can be a 12v Gell.... -
Here is a simple 2. 4 GHz SWR meter which can be easily found, which is based around surplus microwave hardware. The main component is a MECA -20/-20 dB Directional Coupler which has a frequency range of approximately 700 MHz to 2. 5 GHz. This particular.... -
In this circuit I have used a Rotary Switch to select Various Current ranges as a Potentiometer is not very practical for the lower resistance/High Current Ranges. But if you wish to change it to a pot, you can try it. * It is practical to use a pot on the.... -
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.... -
This UHF wideband signal 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 UHF TV signal amplifier to work correctly, you need to cut the components pins as short as possible..... -
The KA2284 are a monolithic integrated circuit disigned for 5-dot LED level meter drives with a built-in rectifying a amplifier, it is suitable for AC/DC level meters such as VU meters or signal meters. Disclaimer All files are found using legitimate search.... -
All car batteries have required a 12v battery charger. And this is also true of Marine, RV and Power Sports batteries. The high efficiency lead acid type batteries available today require more efficient charging techniques. The most important factors in the.... -
Reverse engineered circuit diagram of an expensive commercial variable lab power supply. This unit is designed around an ordinary op-amp and easy to obtain parts. Although the unit uses a single transformer with two output windings the circuit works equally.... -
The switching power supply provides 12 volts, at 10 amps, maximum, using a discrete transistor regulator with an op-amp functioning as a comparator in the feedback circuit. With reference to the schematic, the front panel power-on light is not shown. There.... -
This is a very useful project for anyone working in electronics. It is a versatile power supply that will solve most of the supply problems arising in the everyday work of any electronics work shop. It covers a wide range of voltages being continuously.... -
This electronic circuit is a simple version of an electronic roulette game and is based on the 4017 IC which is a 10 stage decade counter/divider. It is driven by another versatile IC 555 configured as a voltage controlled oscillator (VCO). The 555 timer is.... -
This converter has a central component, the CMOS 4047, and converts a 12V DC voltage to 220V AC voltage. 4047 is utilised as a astable multivibrator. At pin 10 and 11 we find a rectangular symmetrically signal which is amplified by tow Darlington transistors....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
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.... -
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.... -
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.... -
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.... -
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,.... -
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.... -
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.... -
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.....
Popular Circuits
This programmer requires only a basic terminal program capable of uploading an ascii PIC HEX...
Figure A is an R/2R resistor ladder. Each switch that is closed increases the amount of current...
This is an easy to build, but nevertheless very accurate and useful digital voltmeter. It has...
As more than one switches are to be controlled, we have to transmit a number of bits through IR...
The above pictured schematic diagram is just a standard constant current model with a added...
UM3561 is an excellent ROM IC that can generate Multi siren tones simulating Police siren,...
There is one slight drawback to our flashing LED program. Each instruction takes one clock cycle...
I decided to try my hand at building a spectrum analyser after seeing the design by Roger...
The project Thor was started at the High Voltage Institute of HUT (Helsinki University of...
Circuit shown in Figure 3-137. This eliminates the need for a step-down transformer line, using...