100W inverter 12V to 220V

To lower or raise any specific voltage is better adapted from a transformer, but this component does not operate in direct current, which is available in battery or vehicle. Therefore we must put an oscillator that generates an alternative current.
The Integrated circuit (CD4047) is an oscillator that has the output inversely to one another. This means that while if one is high, other states are low and vice versa. The signals are too weak to drive the transformer so that the driver applied consists from three transistors in the chain. Diode in parallel with the end of each transistor prevent reverse current produced by removing the coil current that can burn the transistor. 5A diode placed in parallel with the power line creates a short circuit when the polarity is accidentally reversed, causing the fuse to skip. The 50K preset adjusts the oscillator frequency, which is directly proportional to the frequency of the AC produced in the transformer.  In order for to work stable the oscillator is provided a 220 Ω current-limiting resistor and Zener 9.1V with a filter capacitor.
Common transformer is used to make a lower voltage, but in this circuit will be used inversely (step up). The resulting transformer calculation here is 220v and v 9.3+9.3V, but finding a suitable transformer which sold in stores is difficult, so here which commonly used voltage 9V+ 9V. With this voltage the capacity should be at 100VA.
This 100W inverter circuit need power supply : V max: simple 12V DC, I max: 10A
100W Inverter Calibration: Simply power the system and put a frequency counter or oscilloscope at the output of the transformer. Turn the preset of 50 kΩ located at 4047 until the measured frequency is 50Hz. After this the calibration is complete.
IMPORTANT:
This 100W inverter equipment generates alternating current whose waveform is square. This is because the transistors are arranged in cut / saturation. There is no problem for this inverter to supply resistive equipment such as welders, light or source. But for TV set or video recorder which is used as the reference frequency and wavelength of the network may not be working correctly.

Read More

Surround Sound Decoder

Parts List:

R1-2-7-8-12-13-18-19-20=47Kohm R3-4-5-6-21-22-34-35=10Kohm R9-10-11-14-15-16-17=15Kohm R=23-24-25-33-36=100ohm R26-27-28-31-32=100Kohm R29-30=5.6Kohm C1-8=47uF 25V C2-7-9-14-23=47nF 100V C3-6=1uF 100V C4-5-10=33pF 100V

C11-12-15=10uF 25V C13=82nF C16=18pF 100V C17=100pF mini adjustable capacitor C18=2.2nF C19=4.7uF 25V C20=100nF 100V C21=10nF C22=180pF C24=150nF

RV1-RV2=2X10Kohm  Log. pot. RV3-4=10K Log pot. D1=1N4148 IC1-6=TL072 IC2-3=TL074 IC4=MN3101 IC5=MN3004 JI…..J6=RCA female  jack

How the circuit works:
The circuit’s operation starts as the stereo sound signal transports surround sound information on the master volume part of the circuit. This will drive the Left channel Lch attached to Model TL072 IC1A and IC1b in which Right channel Rch is attached. The outputs on these operational amplifiers would serve as the input buffer to the following stages of the circuit. IC2C is responsible for summing up the signals from the left and right channels that will power the central loudspeaker output while IC2D is responsible for increasing the phase difference between left and right channels which is encoded in the two channels and will be fed to the rear loudspeakers. It is necessary to ensure that the negative terminals between the rear speaker is not earthed because they will simply function in parallel with the main speakers.
The output of IC2D will power regulated delay unit of audio to the rear loudspeakers. This would lead to the creation of proper sense of spacing in accordance to the size of the room. This will incorporate op-amp sound delay signal IC5 MN3004 which has 512 stages. Since IC4 MN3101 is a clocking signal, it provides timing to IC5 as it functions as an oscillator in the circuit. Variable capacitor C17 regulates the delay time in the circuit. The presence of filters in the circuit is for the purpose of preventing noise that will be produced during the process. These filters can be regulated to cut the frequencies above 8 KHz and under 100 Hz, to be able to drive the rear speaker. The rear loudspeaker is small in size because its input is encoded with a bandwidth of 100 Hz up to 8 KHz. The filters are built around the IC6A/B which is also an output buffer. A potentiometer is placed in every output to aid in the adjustment and regulation of loudspeakers and amplifiers. The supplied power in the circuit is 15 V and every output can drive a single power amplifier.
http://circuitdiagram.net/

Read More

Power Amplifier 14W Class A

This class A amplifier circuit requires a preamp as it hasn’t got much gain. It requires big heat sinks and a large transformer and a great power supply and careful wiring, but in the end it is extremely simple and it sounds very good. The zener diode rejects any ripple coming from the power supply, But you still only want a ripple of 10mV max. The ripple reaching the input is amplified, so the zener gets rid of that, but whatever ripple there is will still reach the power stage.
Many early amplifiers operated in Class A, but as output powers rose above 10W the problems of heat dissipation and power supply design caused most manufacturers to turn to the simpler, more efficient Class B arrangements and to put up with the resulting drop in perceived output quality. Why Class A ? Because , when biased to class A, the transistors are always turned on, always ready to respond instantaneously to an input signal. Class B and Class AB output stages require a microsecond or more to turn on. The Class A operation permits cleaner operation under the high-current slewing conditions that occur when transient audio signal are fed difficult loads. His amplifier is basically simple, as can be seen from the block diagram.

Read More