Repository-circuits
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If you want to drill a hole in the wall then you must be sure that there`s no electrical wiring. This simple device. shown on the figure 1, can detect electrical wiring in the walls or ceiling. Resistor R1 protects IC CD4011 against electrostatic. A rigid.... -
The FM radio receiver with PLL designed by A. Zaharov [1] still attracts the attention of radio amateurs. As noted in a publication of the magazine "Radio" [2, 3], one of the major drawbacks of this type of detectors is the low adjacent channel selectivity..... -
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The use of diode rectifiers in AC voltmeters with a low lower limit of measurement range (0. 5. 1 V) leads to significant nonlinearity of the scale because of the nonlinearity of current-voltage characteristics of diodes. The use of electronic amplifiers in.... -
A lots of radio amateurs have an interest to power a simplest radio receivers with the "free energy", i. e. the energy, taken by the receiver antenna directly from the air. The circuits described here can provide a radio reception using a loudspeaker. The.... -
While experimenting with different receivers and amplifiers powered by "free energy", it was found that it is more convenient to connect the audio amplifier to the receiver by using only two wires for audio signals and supply voltage. This would allow to use.... -
The circuit diagram of the non-contact voltage detector is shown on the figure 1. It consist of two parts - the AC amplifier and the audio oscillator, based on the Schmitt trigger DD1. 1 of IC CD4093 with the network R7C2, which determines the frequency of.... -
This is a very sensitive envelope detector for AM radio. The circuit (see Fig. 1) provides linear detection of weak signals with modulation depth of 80. 85% The first stage (VT1) is a common-emitter amplifier circuit for input signals, the second stage is an.... -
The simplest Analog to Digital Converter (ADC) can be constructed as shown in Figure 1. Input voltage which can range from zero up to power supply voltage (Vcc) converts to parallel additional binary code at the outputs of the converter. For normal operation.... -
Typically square wave generators are based on symmetrical multivibrator with bipolar transistors of the same structure and with two frequency determining network. However, you can construct more simple oscillator with two transistors of different structure.... -
The RF stage of the receiver is based on a transistor VT1, this stage works as a mixer and a local oscillator and it works as a synchronous detector. A cable of the headphones works as an antenna. A signal received with this antenna is fed to the input.... -
The timer is used in typical configuration, except that the timing resistor is replaced with the current source based on the op-amp DA1 (741). This solution allowed to obtain a good linearity (better than 3%). With the value of components used in this.... -
A schematic diagram of the oscillator is shown in Fig. 1. The common-base transistor stage (Q1) provides amplification of the signal in the positive feedback loop. The signal of the positive feedback develops across the resistor R1, this resistor is common.... -
This simple tuned radio frequency receiver (Fig. 1) was designed and constructed in the mid 1990s. The receiver was tested under urban and field conditions, in the heat and cold. This simple circuit has quite high sensitivity, good sound quality and.... -
For convenience of use at night the receiver is provided with a scale bias lighting and the surface behind the scale has a fluorescent coating. To illuminate the scale depress button 3. Radio programs can be listened in over the earphone which is connected.... -
The figure below shows a schematic diagram of a simple FM receiver. This receiver made with four transistors. The signal from the antenna through the trimmer capacitor C1 goes to the input of the first stage. This stage is a super-regenerative detector based.... -
This voltage controlled frequency divider circuit (see figure in text) produces pulses of lower frequency that depends on the control voltage, and front edges of input and output pulses are synchronous. Actually, in this type of frequency dividers are used a.... -
The device uses a microammeter with full scale deflection of 50 uA and with the resistance of 2 kilohms. The upper limit of the measuring range of the voltmeter is 1 V, and in the range of 0. 2. 1 V the measurement error due to the nonlinearity of the scale.... -
In this electronic roulette wheel (see Fig. 1. ) the timer 555 works as a generator of pulses with fading frequency. The counter 4017 switches LED`s one by one in the selected string, and the divider by two based on D-type flip flop (4013 IC) selects the.... -
This page provided to the domain owner free by Sedo`s Domain Parking. Disclaimer: Domain owner and Sedo maintain no relationship with third party advertisers. Reference to any specific service or trade mark is not controlled by Sedo or domain owner and does.... -
A low cost device to temporarily disable the reception of the civilian coarse acquisition (C/A) code used for the standard positioning service (SPS) on the Global Positioning System (GPS/NAVSTAR) L1 frequency of 1575. 42 MHz. This is accomplished by.... -
Barrage (noise) jammer for VHF/UHF communications. Based around an old TV tuner with its local oscillator tapped and amplified. The tuner`s voltage tune line is mixed with a sweeping, random noise signal... -
Here remote Sun SPOT will send data to Sun SPOT on car which will drive the IC according to DC IO pins D0 - D3. The IC will drive the Motors which will run the car. package org. sunspotworld. demo; import com. sun. spot. io. j2me. radiogram. Radiogram;.... -
The Tesla Coil I’ll be using will use a HV (High Voltage) power source that gives off 9 kV at around 30 mA. The rest of the Tesla coil will be made of 6 Glass bottles, Table salt, Oil, and Aluminum foil for the capacitors, the Primary coil will be made of.... -
The 1-meg resistor helps protect the FET from being harmed by any accidental sparks to its Gate lead. The circuit will work fine without this resistor. Just don`t intentionally "zap" the Gate wire with a charged object or your charged finger. To test the....
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
The circuit is also an inexpensive VCO (voltage-controlled oscillator) with only five components....
This circuit is a small digital ?roulette''. It is constituted by oscillator IC1, the counter...
This circuit responds to RF signals from below the standard broadcast band to well over 500 MHz,...
To provide good signal-to-noise ratio, this four channel mixer amplifier controls the signal...
This accessory connects to phone and will activate an attention-getting 120-V bell whenever a...
Self-designed amplifier circuit 9 of the circuit described in this article is completely...
As we all know, from the amplifier output stage to the previous stage, although a large loop...