A square wave generator with IC UA741 range shown here.The circuit uses positive feedback to the Schmitt trigger action and negative feedback to measure the time of the waveform. Let us assume that the output is high and the capacitor C1 is fully discharged.C1 now begins to charge through R2 and C1 R1.When tension rises above the junction of R3 and R4, the output changes rapidly totally negative voltage.C1 Now begins the unloading and reloading in the direction.Again contrast, when the negative voltage across C1 falls below that at pin 3, the circuit is returned quickly to totally positive repetitions value.The output endless cycle. The square wave frequency can be varied by varying POT R1.The frequency range of the circuit depends on the value of R3, R4 and C1.

It's a great hobby project, but the scheme is very complicated. This project uses three main devices to create personal radar system. The IR range sensor outputs, the PIC microcontroller that processes and displays the output on the LED array. The objective of this project is to create a working system going radar. The system is only necessary to measure the proximity to a 90 degree angle as shown in the example above. The range of system is approximately 4 to 30 cm, 20-150cm and 1m 5.5 m, depending on the sensors you choose to use.

After several requests of the correspondents, the decision to design a headphone amplifier 9V power was finally taken. The main requirement was to feed the circuit by a common, PP3 (transistor radio) alkaline batteries. Therefore, the circuit implementation of a low current draw was absolutely necessary, while retaining high quality. The emergence of low-noise 5534 operational amplifier at a reasonable price was much appreciated by audio designers. Now it is difficult or impossible to design a specific phase that has the performance of 5534, without the complexity unacceptable. 5534 operational amplifiers are available from various sources, in a conventional 8-pin dil format. This version is internally compensated for gains of three or more, but requires a small external capacitor (5-15pF) for unity gain stability. The 5532 is a convenient pack of two 5534s in an 8-pin device with internal unity gain compensation, since there are no spare pins. The 5534 / 2 is a low distorti...

This unit was designed for fans to have an old vinyl record collection and willing to be digitally remastered on a personal computer. Or sometimes you can hear an old collection of priceless LP, through its modern hi-fi, usually without a preamp stage: this is a circuit capable of meeting their needs. The unit is powered by a 9V battery, allowing for quick and easy connection to all the pre-amp high level input and drawing very low current circuit ensures long battery life. Despite the low voltage circuit performance with moving magnet pick-up is quite good, with high input overload capability, very low distortion and accurate reproduction of the RIAA equalization curve, thanks to one of two stages of the operational amplifier circuit in which the RIAA equalization network is divided into two halves: an input stage of the application of low-strengthening the RIAA equalization curve in a cable series feedback configuration and a second stage, the application of the acute c...

Need a tone control, this module can be inserted into the chain between the Control Center and power amplifier. The circuit is based on an original design by Reg Williamson, published in Electronics World + Wireless World, circuit ideas, January 1991. The tone control circuit will take the form of any of the traditional low treble adjustment, or the type of shelves, which is similar to a "tilt" control, but with separate bass and treble. Asymptotic slopes for both are about 4dB/octave, but begin to level off at 100 Hz and 10 kHz, with a maximum of ± 15 dB at the ends of the audio band. Component values ​​in parentheses are the shelving of control. In this case, the platform starts around 250 Hz and 4 kHz, flatten to a maximum of ± 6dB an octave above or below the central point is 1 kHz. Reactive elements for low-end includes a generalized impedance converter, which simulates an inductor in series with a resistor (spinner). When set to the centers of their respecti...

When there is a break of fire in the room temperature ultra-compact increases.This cheap fire alarm senses fire starter based on this fact. Transistor BC177 (Q1) is used as here.When fire sensor temperature increases the leakage current of this transistor also increases.The circuit is designed so that when there is an increased leakage current of Q1, Q2 transistor will partially. As a result, when a fire break transistor Q2 is on.The emitter of Q2 (BC 108) is connected to the base of Q3 (AC 128). So when Q2 is ON Q3 will also be the transistor Q3 on.The relay units used to carry the load, ie, light, bell, horn etc as an indication of the diode D1 is used as a fire.The freewheeling diode to protect the counter electromotive force generated when the relay is activated. Notes. The Preset R1 can be used to desired temperature level for setting the alarm ON. This is not a latching alarm,ie;when the temperature in the vicinity of the sensor decreases below the set point the alar...

LM12 operational amplifier can output currents up to 10A. The LM12 in encapsulated in TO-3 with 4 pins, can support up to 800W and has enough internal protections to prevent slacks from over-currents or over-heating. You can use LM12CL with 30 V maximum voltage or LM12C with 40V maximum. The L1 coil has 40 turns 1mm copper, coiled over R4. If you use LM12CL it is recomended to have toroidal transformer 2 x 22V. The output must be between 7 and 12A. Filtering capacitors must have at least 20.000 uF. LM12 must be mounted with screws on a big heatsink (=< 1.50 C/W) and electric isolated form the heatsink. via: electroschematics.com

This car booster stereo using LM2896 an integrated circuit that has two integrated amplifiers. It can be powered with voltages up to 15 volts. The output power is 2.5 watts per channel with an 8 Ω load and supply voltage of 12 volts. Using tehnique bridge circuit has an output of 9 watts. The car audio reinforcement can be powered from 3 to 15 volts. The load impedance can be connected to its output can be either 4 or 8 Ω Ω. The supply voltage and load impedance influence the output power level. This amplifier circuit is designed as a booster to the car radio / cassette players. The power consumption for maximum power and a 4 Ω load is 1 ampere.

FM transmitter circuit very stable and simple given here. With an adaptive antenna, the transmitter can reach a range of about 200 meters. Transmitter met this year and got a few good results. Let's see how the circuit. A condenser microphone (K1) is used to collect the sound transmitted. The capacitor C1 is a DC decoupler and the audio signal is coupled to the base of Q1 which connects a preamplifier.R2 and R3 are the resistances of polarization of Q1. Amplified sound signal will be available at the collector of Q1 and, together with the emitter of transistor Q2 through capacitor C4 and inductor L1 1mH. C4 capacitor decouples the DC component of the preamplifier output. Q2 does the work of the oscillator and modulator. Inductor L2 and capacitor C5 variable tank circuit is necessary to create oscillations. Capacitor C6 is the feedback capacitor. The FM modulated wave will be available at the collector of Q1 and is transmitted through the antenna A1.

TDA 2030 is produced by SGS Ates and is a complete audio amplifier . Class AB amplifier to deliver final cand 14 watts into 4 ohms, a source of +-14V power. Connecting two TDA2030 through cheap power transistors that can create an amplifier that can deliver a higher power. With the value of the components of the overall scheme of the amplifier gain is 32 dB. The speaker may be 2 ohms instead of 4 ohms, if we use the transistors TIP. With a properly designed power supply that can output audio amplifier 200W. Active components: IC1, Ic2 TDA 2030 T1, T3 = BD 250, TIP 36 T2,T4 = BD 249, TIP 35 D1 … D4 = 1N4001

Active speakers have many advantages over the simple speakers using passive materials for implementing the components separation of frequencies. In the case of active speakers have proportionally higher manufacturing costs, since each loudspeaker is driven by its own amplifier. In a properly designed active speaker, the sound quality is much better and very low distortion, because it uses inductors and capacitors in the signal path,. Those capacitors are on the path of the signal have a very small price and very good quality. This does not mean that a well designed passive speaker is good, maybe better than an active. Unlike an active speaker is much more difficult to manufacture. In [Fig.1], is an active channel speaker 2-way. As shown in the Block diagram [Fig.2], is a classical crossover 2-way crossover fc = 3100HZ -24dB/oct. This frequency was chosen because it is near the crossover of many speakers of trade, but can be changed and customized to your choice of speakers, enough to ...

The combination of controller IC LM4651 and LM4652 Class D MOSFET power amplifier IC power amplifier solution provides a high efficiency, suitable for powered speakers, subwoofers and amplifiers car quality. The LM 4651 is a fully integrated conventional pulse width modulator (PWM) driver, which contain low-voltage circuit, short, overshoot, and thermal shutdown circuit protection. The IC has a standby function which shuts the pulse width modulation, minimizing the current bid. The LM 4652 is a fully integrated H-bridge power MOSFET IC in a TO220 power pack. The IC has a temperature sensor to alert the LM4651 when the die temperature exceeds the threshold limit. Used together, LM4651 and LM4652 as a simple, compact, efficient, high quality audio power amplifier complete solution for protection, usually seen only in class AB amplifiers. The maximum efficiency of this circuit is 85% to 125 W with an expected attenuation of greater than 100 dB. The THD at 10W, 4 ohm, 10 - 50...

The audio power amplifier of this scheme is a power amplifier based on TDA7296 chip . The audio amplifier is a class AB amplifier, which can be used in high fidelity (stereo, speakers powered car, TV five stars). The maximum output power obtained with TDA7296 amplifier circuit is about 60 watts. Thanks to the wide range of voltages and high power output capability is able to provide the highest power in 4 and 8 ohm impedance load. The TDA7296 is provided with both stand-by and mute two independently driven by CMOS logic input pin compatible and optimized to avoid any kind of uncontrolled audible transient at the output. The maximum power of 60 watts is obtained with a power supply around 29V VS = ± 8 ohm load impedance, VS = ± 24V, 6-ohm load impedance, VS = ± 22V 4-ohm impedance loading. The 60-watt maximum power delivery of the audio circuit is obtained with a 10% total harmonic distortion. Use a power supply around VS = ± 24V, 8 ohm load impedance, VS = ± 21V, 6-ohm load impe...

This is the circuit diagram of 15W OTL audio amplifier based single power IC TDA2030. The TDA2030 is a popular power chip for low power amplifier circuit . The circuit will deliver about 15W audio power when use 8ohm loudspeakers. For maximum power output, you need 24VDC power supply with 1A current, for single/mono channel. Use power supply with 2A minimum output current for stereo channel. Do not forget to mount a heatsink on the IC. 15W OTL Audio Amplifier PCB design

Stereo Amplifier Circuit with BA5406 In the this circuit diagram, BA5406 is configured to deliver 5 x 2 watts at 4 ohm speakers to a supply voltage of 9 volts. The capacitor C3 is a power supply filter capacitor. C11 and C12 are decoupling capacitors DC input for the left and right. C3 and R2 form a Zobel network to output the left, while C6 and R3 is the same for the right channel. Zobel network purpose is to reduce vibrations and improve the high frequency stability of the amplifier. Potentiometers R5 and R6 serves as a volume control for left and right channels. C8 pair CapacitorsC4 and the amplifier outputs to the speakers. C9 and C10 are the noise filtering capacitors. C1 and C5 are starting capacitors for left and right channels. Notes. BA5406 requires a proper heat sink. Supply voltage range is 5 to 15V DC. I used 9V DC for powering the amplifier. The power supply must be well regulated and filtered

This is the circuit diagram of Class-AB headphone amplifier which built using 3 transistors of BC549 and BC559. The circuit is very simple and will give you good audio performance. The power consumption of this headphone amplifier circuit is claimed to be very low. Two pieces of AA battery will supply the circuit for long time. Components List: R1 - 100K R2 - 330 R3 - 100 R4 - 22 (2 - 4.5V) R4 - 100 (5 - 12V) C1 - 4.7uF C2 - 4.7uFC3 - 100 - 1000uF C4 - 220uF P1 - 100K D1, D2 - 1N4148 Q1, Q2 - BC549 Q3 - BC559 Specifications: Power Supply Voltage: 2 - 12V Power Consumption: 10mA/3V - 30mA/12V (measurements taken using a stereo version) Output Power: 300mW The circuit can be used for common electronic devices such as radios, CD/DVD Players, computers, audio/video players, ipods etc. Circuit Source: Class-AB Headphone Amplifier Circuit