Sensor Circuits
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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.... -
Inverters Ula and Ulb are connected in a simple RC oscillator circuit. The frequency is determined by the values of Rl, Cl, C2; and the internal characteristics of the integrated circuit. As long as the circuit is oscillating, a positive dc voltage is.... -
The circuit uses a 741 op amp operating as an inverting amplifier to amplify the voltage produced by an 8-ohm speaker used to detect any sounds. The feedback resistor R3, a 1-megohm potentiometer used to vary the gain of the amplifier determines the.... -
Basic operation of the monitor attached to the circuit is to detect objects (obstacles), at distances ranging from a few millimeters to and a few centimeters. Depending circuits used in industry and hospitals. The position sensor IC2 optoapomonotis used a.... -
Assume the correct phase sequence to be VA-VB-VC. The circuit terminals are connected such that Tl gets connected to phase A and T2 to phase B. The capacitor advances the voltage developed across R2 due to phase "B" by — 60°, while the voltages developed.... -
This circuit prevents damage to the load due to incorrect phasing. The three power SSR's are only permitted to turn-on for a phase sequence of phase A leading phase B. If phase A lags phase the input currents will cancel, causing the SCR and the inhibit SSR.... -
ICla and IClb are wired as a slow astable multivibrator and IClc-ICld are wired as a fast astable. The output of the slow astable modulates the frequency of the fast astable, and the output of the fast astable is fed to the external speaker via the Ql VMOS.... -
Signals of identical frequency are applied to sync input (Pin 6) and to the demodulator input (Pin 4), respectively, the demodulator functions as a phase detector with output dc component being proportional to phase difference between the two inputs. The.... -
Simple frequency limit detectors providing a GO/NO-GO output for use with varying amplitude input signals may be conveniently implemented with the ICL8211/8212. In the application shown, the first ICL8212 is used as a zero-crossing detector. The output.... -
The MC1596/MC1496 makes an excellent SSB product detector. This product detector has a sensitivity of 3 microvolts and a dynamic range of 90 dB when operating at an intermediate frequency of S MHz. The detector is broadband for the entire high frequency.... -
The circuit will provide a dc output equal to the rms value of the input. Accuracy is typically 2% for a 20 Vpp input signal from 50 Hz to 100 kHz, although it"s usable to about 500 kHz. The lower frequency is limited by the size of the filter capacitor.. -
Detector uses three sections of an L144 and a CMOS NAND gate to make a very low power voltage monitor. The 1 MO resistors Rl, R2, R3, and R4 translate the bipolar ±10 V swing of the op amps to a 0 to 10 V swing acceptable to the ground-referenced CMOS logic.. -
The detector circuit is made up a two-amplifier multiple feedback bandpass filter followed by an ac-to-dc detector section and a Schmitt Trigger. The bandpass filter (with a Q of greater than 100) passes only 5Q0 Hz inputs whch are in turn rectified by Dl.... -
The timing cycle is continuously reset by the input pulse train. A change in frequency, or a missing pulse, allows completion of the timing cycle which causes a change in the output level. For this application, the time delay should be set to be slightly.... -
This detector is useful in sine wave squaring circuits and A/D converters. The positive input may either be grounded or con-output nected a nulling voltage which cancels input offsets and enables accuracy to within microvolts of ground.. -
This circuit is useful for signal-processing sonar data recorded on an instrumentation-quality analog tape recorder. The envelope detector utilizes ready available parts, and furnishes accuracy beyond 100 kHz. Two LM301 op amps connected as precision.... -
The circuit can be used to tell whether or not an input signal is within a certain frequency range. The device consists of three !Cs, a dual monostable multivibrator, and two dual D-type flip-flops. The signal whose frequency is in question is fed to the.... -
The 555 is a monostable that wants a negativegoing trigger. If the pulse you"re feeding it with is positive-going, you can run it through an inverter made up of either an inverting gate or, if you"re tight on space, a single transistor. Both ways are.... -
This circuit requires low noise, low and stable offset voltages, high open loop gain, and high speed. These requirements are met by the HA514 7. The standard variations of this circuit can easily be implemented using the HA-5147. For example, hysteresis.... -
Requiring only two ICs to monitor a train of positive pulses, this circuit produces a single positive output pulse for each input pulse whose duration is either too long or too short. You specify the minimum and maximum limits by adjusting the trimming.... -
This circuit will detect a missing pulse or abnormally long spacing between consecutive pulses in a train of pulses. The timer is connected in the monostable mode. The time delay should be set slightly longer than the timing of the input pulses. The timing.... -
The peak detector tracks and holds, using the charge-storing ability of a capacitor, the highest output voltage from a transducer. Initially, the voltage on the inverting input of the comparator is at ground level. As a small voltage (0-5 V) is captured by.... -
This circuit can detect the positive peaks for signal frequencies higher than 5 MHz. It yields ±1% accuracy for 400 mV to 4 V pk-pk signal amplitudes on sine, square, and triangular waveforms. The Am685 comparator output increases whenever VrN is a.... -
The tracer receiver is a stereo audio amplifier/detector circuit operating near 1 kHz. Inductors Ll and 12-hand-wound coils, consisting of 200 turns of #26 wire on 2-inch ferrite cores-are tunea to the operating frequency of the amplifier/detector. The.... -
This circuit passes the input signal at unity gain, either unchanged or inverted, depending on the digital control input. A buffered input is shown, since low-source impedance is essential. Gain can be added by modifications to the feedback networks..... -
The output of the detector contains a term related to the cosine of the phase angle. Two signals of equal frequency are applied to the inputs. The frequencies are multiplied together, producing the sum and difference frequencies. Equal frequencies cause.... -
Oscilloscope measurements of ground noise can be unreliable because noise can enter your circuit via the scope"s three-pronged power plug. You can avoid this problem by using the ground-noise tester shown. Powered by two 9-V batteries, the circuit.... -
The unit is constructed around a balanced-bridge circuit. using both capacitance and inductance. The bridge consists of capacitors C2 and C3, and the center-tapped winding of Tl. One end of the bridge is coupled to ground by C4, while capacitance changes.... -
This circuit detects frequency variation above or below preset limits. IC1 is a binary counter docked at FcLK· The outputs are comparea with switch preset values by IC2 and IC3. The input signal, which must be a positive-going pulse, is used to reset IC1..... -
This circuit de-energizes a normally energized relay if the input voltage goes above or below two individually set voltages. The transistor driving the relay is normally turned on by R4, so the relay is normally energized. Ifthe cathode of Dl or D2 is.... -
This simple window detector uses only half of a 7400 quad NAND gate plus four resistors, chosen so that the voltage at point A exc.,eds the voltage at point B for any input voltage. With no input applied or when VIN is at ground, the output of gate Gl is.... -
Sensing short circuits in equipment that performs under water is especially critical, but Fig. 20-4"s wet-mat..
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....
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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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