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Human Sensing Circuits
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Optical Sensing Circuits
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AC to DC & DC to DC
Solar Cell Circuits
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Switching Power Supplies
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Data Bus Circuits
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RF Converter Circuits
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voltage to frequency
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Video Wall circuits
TV Video Circuits
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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
Meter Counter Circuits
ICL7106 constitutes a micropower thermometer
LCD RF Power meter AD8307 sensor schematic
1-Wire Barometer Calibration
The resolution of the barometric pressure is about 0. 00417 inHg (0. 0139 kPa) for a pressure range of 31. 0 to 28. 0 inHg (105. 0 to 95. 0 kPa, or 1050 to 950 mb or hPa). Better resolutions are possible with a more restricted pressure range. The circuit requires an additional power source other than that of the 1-Wire network. The MPX4115...
Capacitance Meter Circuit
Capacitance meter is one instrument that you should have in your toolbox if you are an electronics hobbyist, or if you`re a professional electronic technician..
Inductance Meter Adapter Circuit Turns Your Digital Voltmeter to Inductance Meter
Measuring inductance is important in making your hand-made inductors, especially when you do-it-yourself (DIY) your coil winding. An inductance meter adapter..
Simple pH Meter Circuit A Low Cost Adapter for Your Digital Voltmeter
What is A pH Meter? A pH meter is actually a precise voltmeter that measures the generated voltage of a pH electrodes. The requirement of such meter is high..
Accelerometer Signal Amplifier
Inverting mode amplifier is needed by precision accelerometers because that usually charge output device. This amplifier is used to convert charge into voltage..
Temperature Probe for Digital Multi Meter
This is a simple temperature measurement probe circuit. This circuit measures temperature either on a PC board or at the probe tip to which contains the..
This is a circuit of FETVM-FET Volmeter. The function of the VTVM is replaced by the FTEVM while at the same time ridding the usual line cord instrument. This..
LM135/235/335 Centigrade Thermometer
LM135/235/335 temperature sensor is designed ease absolute temperature reading, giving all positive value for any frequency, that`s why we read 2.7315V at 0..
Car Tachometer with 555 IC
Pulses are received by the timer from the distributor points. When the timer output is high, Meter M receives a calibrated current through R6. The meter don`t..
Voltmeter With LED For Car Battery
Below is a comparator circuit which is can measure with step of 1 volt, the voltage of car battery. The indication of voltage is done by comparison of ..
DC RMS And Peak-to-Peak High Impedance Voltmeter
Analog meter normally doesn`t have high impedance since they don`t have buffer circuit inside. With active buffering, the input impedance of this circuit..
Peak (Pulse) Voltmeter
This is a Peak Voltmeter circuit. This circuit can be viewed as a pulse stretcher, which catch fast pulse signal to be measured by a slow response voltmeter..
Optical Pyrometer Detect The Spectrum Composition
This pyrometer is used to measure an incandescent body. The principle for this measurement is that the hotter the body, the spectrum of the radiation will..
Resistance Thermometer Current Loop Transmitter
Resistance temperature sensor (RTD, resistive temperature device) comes in NTC (negative temperature coefficient) and PTC (positive temperature coefficient)..
Five-Decade Dynamic Light-Level Meter
This is a Portable light-level meter circuit with five-decade dynamic range. This uses a single cell battery as the power supply. To calibrate this circuit,..
LM3915 Vibration Meter
A vibration meter circuit shown in the following schematic diagram uses LM3915 a the main active component. This vibration meter uses a piezoelectric..
Digital pH Meter Signal Conditioner with Pulse/Frequency Output
A signal conditioner for pH meter probe is required to have high input impedance. The signal conditioning of the pH meter probe is done by providing a buffer..
Exploring a digital I2C/SPI accelerometer (MMA7456L) with Bus Pirate
Bus Pirate is a great tool for exploring new chips using your PC, without the need to integrate the chip into a MCU project. Once I received my unit, i decided to put it to the test by exploring an accelerometer with I2C/SPI interface the MMA7456L from Freescale. I am writing this in hope that it will help other people get started with BusPir
Build an Analog Bar Graph Expanded Scale Voltmeter
An expanded scale voltmeter (ESV) can save your plane. That may be a strong statement, but it`s true. The crucial radio link that lets you control your plane relies on nickel-cadmium (NiCd) batteries in the transmitter and receiver. If either of these batteries goes dead, you`ll lose control and your plane will likely crash or fly away. Unlike car
Build an LED Bargraph Optical Tachometer
Ultrasonic anemometer Ultrasonic wind sensor
This ultrasonic anemometer serves for the 2-dimensional capture of the horizontal components of the wind speed and the wind direction as well as the virtual temperature. On account of the high measuring rate this device is suited very well to capture gusts and peak value measurement without sluggishness. The accessible exactness with the measureme
Quad comparators, type LM339. A flyback DC converter Done. Buck converter Step-up converter Done. that would consume several comparators and maybe there would be some nice LEDs, too. Then it hit me. A VU meter, big, beautiful, professional! From that moment started mythoughts flowing. Those VU-meter ICs that are sold in every electronics shop...
Inductance and Capacitance Meter Adapter
Another project started with three others not finished. What would my Dad say Well one thing he would say is, "Warn people that this project is under construction and has not been proved to work yet". You have been warned. I had to use a signal generator, resistor, and oscilloscope to measure the value of an inductor for my battery-charger projec
High Precision Volt Meter
Audio mV Meter
This was my first AS Electronics project which I built way back in 1998! The original report, with diagrams, is shown here and a PDF version of the report is available for download. There are many occasions where I need to be able to measure small audio signals from various pieces of equipment and circuits. A millivolt meter would be very handy on
Electronic VU Meter
A portable CD player, radio, cassette player, a couple of microphones and PC sound card. I am feeding these into the inputs of an audio mixer the output of which is attached to a pair of active loudspeakers. I want to be able to monitor the signal levels going in and coming out of my audio mixer to make sure that I am not overloading the next...
Wide Dynamic Range Field Strength Meter
A field strength meter is a very handy tool for locating a transmitter. A sensitive field strength meter by itself has some limitations, however: It will respond to practically any RF signal that enters its input. This property has the effect of limiting the effective sensitivity of the field strength meter, as any nearby RF source (or even ones f
Frequency Meter Circuits
VU Meter 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
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