Figure 39-2`s circuit combines a low-noise op amp, IC1, with a chopper-based carrier-modulation scheme to
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achieve a low-noise, low-drift dc amplifier whose performance exceeds any currently available monolithic amplifier. The amplifier"s offset is less than 1, and its drift is less than 0.05 /iV/°C. This circuit has noise within a 10-Hz bandwidth less than 40 nV. The amplifier"s bias current, which is set by the bipolar input of IC1, is about 25 nA. The 74C04 inverters (IC3 to IC6) form a simple 2-phase square-wave clock that runs at about 350 Hz. The complementary oscillator signals ( and O2) provide drive to SI and S2, respectively, causing a chopped version of the input to appear at ICl"s input. IC1 amplifies this ac signal. S3 and S4 synchronously demodulate ICl"s square-wave output. Because S3 and S4 switch synchronously with SI and S2, the circuit presents proper amplitude and polarity information to IC2, the dc output amplifier. This output stage integrates the square wave to provide a dc voltage output. Rl and R2 divide the output and feed it back to the input chopper where the divided output serves as a zero signal reference. The ratio of Rl and R2 sets the gain, in this case to 1000.
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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