Sensor Circuits
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The schematic show that the AccelR8 only uses 3 IC`s. An AVR 8515 microcontroller do the calculation work and controls the other circuits. An MAX603 controls voltage and power-on/power-off. And the chip that makes it all possible, the ADXL202 from Analog.... -
This power-stingy combination of an audio codec and touchscreen-interface controller now comprises a differential or two-channel microphone input with automatic level control, a two-channel audio-line input, a separate monophonic-audio input, a PC-"beep".... -
This is a simple capacitance meter which can measure capacitance value easy. There are some measurement methods for capacitance, at one time the capacitance was measured with a impedance bridge or a dip meter. Recently typical capacitance meters can measure.... -
This simple add-on capacitance meter has been specially designed to help you identify capacitors from 1p to 10u. There has always been a problem identifying capacitors, due to the enormous variety in size, shape and coding. Most of the time it is impossible.... -
This very simple circuit acts as a high sensitivity capacitive sensor. Lamps and/or Buzzers are operated at half the mains supply voltage when a part of the human body comes in contact with the sensor or approaches it at a close distance. The circuit can be.... -
You can use a multimeter with capacitance-measurement capability to measure the length of wire or cable to an open circuit. The capacitance of a pair of wires (or a wire to a shield) is directly proportional to the length of the wire. If you know the....
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The simple circuit in Figure 1 uses a low-current-drain MAX4073H amplifier to sense the current flowing through a 4- to 20-mA loop. The circuit senses the current through a 1 resistor with a fixed gain of 100 and uses no battery or dc power supply. The low....
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This circuit was designed on request, to remotely monitor when a couple of electric heaters have been left on. Its sensor must be placed in contact with the feeder to be able to monitor when the power cable is drawing current, thus causing the circuit to.... -
High-speed current sensing presents a designer with some significant challenges. Most techniques for sensing current involve measuring the differential voltage the current produces as it flows through a sense element, such as a resistor or a Hall-effect....
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The simple ADC in Figure 1 is perfect for getting analog signals into a purely digital microcontroller. Using just five surface-mount parts, you can assemble it for less than 50 cents (1000), which is approximately half the cost of a single-chip-ADC approach....
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The residual-current circuit breaker in Figure 1 continuously monitors the supply lines for any leakage current and immediately disconnects the supply if necessary. Load-supply wires, both live and neutral, pass through the magnetic core of the CR4311-5....
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The accurate, high-side, current-sense circuit in Figure 1 does not use a dedicated, isolated supply voltage, as some schemes do. Only the selected transistors limit the common-mode range. The circuit measures the voltage across a small current-sense....
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The simple circuit in Figure 1a can sense both low and high current levels without low sensitivities or loss of accuracy either at the low or the high end of the scale. The circuit is useful for discerning either low or high currents in noisy environments...
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Several integrated high-side current-sense amplifiers, such as the MAX4172 (Maxim Integrated Products, www.maxim-ic.com), make it easy to measure the current from a positive power supply. With a couple of resistors, these devices provide a ground-referenced....
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The simplest technique for measuring current in an actuator or a motor is to monitor the ground current with a resistive element between the load and the ground. Because the device and its associated electronics share a ground potential, you need to amplify....
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You use high-side current monitoring in many battery-powered products that require accurate monitoring of load current, charger current, or both. In applications for nonportable designs, high-side-current monitoring serves as a power-supply watchdog that can....
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All dedicated current-sense amplifiers provide high-side sensing on a positive supply, but you can adapt such circuits for monitoring a negative supply (Figure 1). The positive-supply pin, V+, connects to the system`s positive supply, and the ground pin,....
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The circuit shows the method of `mirror` current sensing a MOSFET. A fully conducting MOSFET is resistive and behaves exactly as a resistor. It therefore you limit the voltage across the MOSFET when it is conducting you automatically limit the current.... -
The task of sensing dc current at high voltage is often problematic. Most high-side current-sensing ICs available off the shelf are good only to 30 or 40V. Combining an optocoupler with such an IC yields a sensing circuit in which the only limitation of the....
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The common JFET current-source in Figure 1a has average output impedance and depends heavily on the JFET`s VP and IDSS variations. These manufacturing variations limit the initial accuracy of the current setpoint that the circuit can obtain with a fixed R1.....
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Isolated flyback converters usually evoke thoughts-or bitter memories-of custom transformers, slipped delivery schedules, and agency-approval problems. Off-the-shelf flyback transformers carry isolation ratings of only 300 to 500V and rarely of as much as 1....
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Here`s the schematic of the device depicted in the photo. Each of the ten coil-assemblies has its own copy of the above circuit. The SS41 is a Microswitch Hall Effect magnetic field sensor IC that I found in Surplus catalog for $.50 each. Any similar hall IC.... -
Variable-reluctance sensors are preferred for industrial and automotive environments, because they sustain mechanical vibration and operation to 300°C. In most applications, they sense a steel target that is part of a rotating assembly. Because the....
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Power-supply designers usually like flyback converters to operate in DCM (discontinuous-conduction mode) rather than in CCM (continuous-conduction mode). In DCM, the flyback converter is a first-order system at low frequencies, which eases the feedback-loop....
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In the circuit of Figure 1, assume that a brush-type dc motor must drive a load back and forth between two endpoints on a lead screw. Optical sensors determine end of travel, and an SPDT switch selects to which end to send the load. The sensors themselves....
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After (years) of mucking about with this, I finally put together a really slick tach that I`ve had in use for a long time. PCBs are available to experiment with, the source code and schematics are open, the code is well tested and mature, so what are you....
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A speedometer measures a wheel`s rotational speed. Unlike conventional mechanical and moving-magnet designs that use analog moving-pointer displays, the electronic speedometer in this Design Idea features a digital readout and a power-saving device that uses....
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Anyone performing their own automobile tune-ups knows how important it is to know your engines speed. With this tachometer, you can measure your engines speed without any connections or annoying timing lights... -
These pages describe my project to build simpler and less expensive amateur seismometers by using microprocessors and other new chips, such as switched capacitor filters. I have tried to provide links to much of the excellent information that is already on....
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Commercially available IR distance rangers typically handle a 3- to 30-in. detection distance. Many times, it is necessary to determine smaller distances. The circuit in Figure 1 is useful for measuring small distances to reflective surfaces. Its measurement....
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Peak reading meters, popular in Europe for years, are just now coming into greater favor in America, and for good reason. The main purpose for having a VU meter is obviously to monitor signal levels going to a tape recorder, reverb unit, or some other.... -
This circuit was designed to provide a valuable test equipment tool for sound reinforcement systems like guitar amplifiers and the like. Used in conjunction with a signal generator it can be of considerable help in setting and controlling levels through any....
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.....
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