Thursday, November 20, 2014

Metronome Generator Circuit using NE555

Here is a simple circuit with NE555 IC that can be used to generate metronomes.Such circuit is very useful for those who learn music. The circuit is simply an astable multivibrator NE555 cable around. The components R1, R2 and C1 determine the frequency

Notes.

  • The circuit can be wired on a general purpose PCB or common board.
  • The circuit can be powered from a 9V PP3 battery.
  • The POT R1 can be used to adjust the rhythm of the sound.
  • The POT R2 can be used as volume control.
  • The speaker k1 can be a n 8 Ohm tweeter.
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Wednesday, November 19, 2014

Audio Peak Indicator Circuit

The existence of the peak indicator "Audio Peak Indicator" in an audio device is needed. Audio Peak indicator is a simple circuit to detect the peak level of audio signal. Audio Peak indicator circuit is built with duabuah transistor and LED indicator as peak level detection of audio signals.


The main function of a series of Audio Peak indicator is to determine the occurrence of the peak level of audio signal that is more than +4 dB, equivalent to 1.25 V rms. If the received audio signal Audio Peak Indicator more than +4 dB was the LEDs in series Peak Audio This indicator will light. Audio Peak indicator circuit is mounted on the output audio system.
Audio Peak Indicator Component List:
R1 = 10Kohm
R2 = 1.2Kohm
R3 = 220Kohm
R4-5 = 4.7Kohm
C1 = 47uF 25V
C2 = 2.2uF 25V
Q1-2 = BC550C
D1 = LED RED

We hope to form the reference materials in the manufacture of circuit pernagkat Audio Peak Indicators in the audio readers.
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Tuesday, November 18, 2014

6 Watt Audio Amplifier Schematic Circuit with TDA1519

66 Watt Audio Amplifier Schematic Circuit with TDA1519

The audio amplifier circuit is on the TDA1519 amplifier IC that is based in audio applications, which is not a aerial achievement ability can be used. The ambit TDA1519 is a ability of 2×6 watts.

The TDA1519 is an amplifier congenital Class B dual-output advance in a 9-by-line (SIL) artificial amalgamation boilerplate achievement is primarily developed for car radio applications.

Key Features of the audio amplifier IC TDA1519 are: Requires few alien components, anchored gain, acceptable bounce drive, aphasiac / standby mode, thermal protection, about-face polarity safe. Tda1519 amplifier ability rating, 14.4 volts.

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Monday, November 17, 2014

Wave antenna 5 8 pro VKV FM

Wave antenna 5/8 consists of a vertical radiator which is fed at the base of the antenna. A suitable device of some sort should be added between the antenna and feedline if you want to eat with coax. Adding a coil in series with the antenna on the base is one of these methods are suitable. 



So why would anyone use an antenna 5/8 wave if they have to go through all that extra work? After all, a ground plane antenna provides a good match. There are several answers. The first is GAIN. The computer shows that the antenna (mounted 1 foot above the ground) has a margin of about 1.5 dBd higher than a dipole (also installed 1 foot above the ground.)The second reason you might want to use the wave 5/8 vertical is to get a lower angle of radiation. Peak radiation angle A half-wave antenna is 20 degrees. You will find that the angle 5/8 wave antenna radiation is only 16 degrees so it is better dx antenna. 

 You may have noticed a pattern developing here. A quarter-wave ground plane antenna has a radiation pattern that produces the maximum gain at about 25 degrees and half-wave antenna drops to 20-degree angle, and wave antenna 5/8 further drops to 16 degrees angle. So why not just keep extending the antenna to one full wave? Well it would be nice if it worked, but unfortunately the wave patterns begin to create a very high angle of radiation waves exceed 5/8. So weve reached the maximum gain at this point and extend the antenna further reduce profits only where we want it (low angle). 

Of course if you are interested in a very short jump, extend the antenna will produce a nice profit on the dipole.All the length of the antenna depends on various factors. Some of these factors are: height above ground, the diameter of the wire, nearby structures, the effects of other antennas in the area and even the conductivity of the soil.This page allows you to calculate the wavelength for the antenna 5/8. It uses the standard formula, 585 / f (178.308 / f for metric) MHz to calculate the length of the element. If you have experimented with 5/8 wave antenna before and know a better formula for your QTH, feel free to change the formula accordingly. This formula is for the antenna wire. 

Of course if you build your antenna out of the tube, total length of the antenna will be shorter, for example I have found that 21.5 feet seems to provide maximum benefit to the frequency of 28.5 MHz when using a 1 "tube, and 22.5. Foot seems be the best long-wire at the same frequency. Since the formula to calculate the antenna to be about 2 feet shorter, be sure to experiment and maybe add a little for your final term.
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Friday, November 14, 2014

FM TRANSMITTER

This is a very interesting and simple project in the series of communication used to transmit noise free F.M. signal in the wide range up to 100 M using only one transistor. The transmitted message from F.M. transmitter circuit is received by the receiver having the facilities of F.M. channel.

Circuit Description

The entire circuit of F.M. transmitter is divided into three major stage i.e. oscillator, modulator and amplifier. The transmitting frequency of 88-108 MHz is generated by adjusting VC1. The input voice given to microphone is changed into electric signal and is given to base of transistor T1. Transistor T1 is used as oscillator which oscillates the frequency of 88-108 MHz. The oscillated frequency is depended upon the value R2, C2, L2 and L3. This transmitted signal from F.M. transmitter is received and tuned by F.M. receiver.

Circuit Diagram


Parts List

Resistors (all ¼-watt, ± 5% Carbon)
R1 = 180 KΩ
R2 = 10 KΩ
R3 = 15 KΩ
R4 = 4.7 KΩ

Capacitors
C1 = 10 KPF
C2 = 10 PF
C3 = 20 KPF
C4 = 0.001 µF
C5 = 1 µF/10V
C6 = 4.7 PF
C7 = 10 KPF
C8 = 3.3 PF
VC1 = 22 PF

Semiconductor
T1 = BF194B

Miscellaneous
MIC1 = Condenser mike
L1, L2 = 3 turns of 22 SWG wire around any thin pencil
L3 = 2 turns of 22 SWG wire around any thin pencil.
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Thursday, November 13, 2014

BC557 based Flashing Eyes circuit with explanation

 bc557 based flashing eyes circuit with explanationTwo-LED-eyes follow the rhythm of music or speech, 3V Battery-operated device suitable for pins or badges

This circuit was purposely designed as a funny Halloween gadget. It should be placed to the rear of a badge or pin bearing a typical Halloween character image, e.g. a pumpkin, skull, black cat, witch, ghost etc. Two LEDs are fixed in place of the eyes of the character and will shine more or less brightly following the rhythm of the music or speech picked-up from surroundings by a small microphone. Two transistors provide the necessary amplification and drive the LEDs.

Parts:
R1 = 10K
R2 = 1M
R3 = 1K
C1 = 4.7uF-25V
C2 = 47uF-25V
D1 = 2mm LED
D2 = 2mm LED
Q1 = BC547
Q2 = BC557
B1 = 3V Battery
SW1 = SPST Switch
MIC1 = Electret Mic

Notes:
* Any general purpose, small signal transistor can be used for Q1 and Q2, but please note that R3 could require adjustment, depending on the gain of Q1. For medium gain transistors, the suggested value should do the job. High gain transistors will require a lower value for R3, i.e. about 390 – 470 Ohm. You can substitute R3 with a 1K Trimmer in order to set precisely the threshold of the circuit.
* Any LED type and color can be used, but small, 2mm diameter, high efficiency LEDs will produce a better effect.
* No limiting resistors are required for D1 and D2 even if this could seem incorrect.
* Stand-by current consumption of the circuit is about 1.5mA.
* Depending on dimensions of your badge, you can choose from a wide variety of battery types:
* 2 x 1.5 V batteries type: AA, AAA, AAAA, button clock-type, photo-camera type & others.
* 2 x 1.4 V mercury batteries, button clock-type.

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Wednesday, November 12, 2014

Build Power Amplifier LM3876 Simply and Powerfull Power Amplifier

The chip on which the amplifier is based, a Type LM3876, is a member of the Overture family from National Semiconductor, All members of this family are pin-compatible and mutually interchangeable. They are typified by an internal protection (called SPIKE). In practice, the diftection ference between them is the power output. The series was described on the basis of the LM3886 in an earlier issue*.

The PCB has been designed so what it can accommodate the LM3876 (50W) as well as the LM3886 (150W). Because of this, pin5 of the IC on the board is connected to the positive supply line. This connection is not needed for the LM3876, since its pin5 is not (internally) connected (NC).

The IC is located at the side of the board to facilitate fitting it to a heat sink as shown in the photograph.

An important aspect for optimum performance is the decoupling of the unregulated supply lines by C 7-10. All earth connections go to a single terminal on the board.

Air-cored inductor L1 consists of 13 turns of 1mm dia. enamelled copper wire with an inner diameter of 10mm. The completed inductor is pushed over R7 and its terminals soldered to those of the resistor.

All electrolytic capacitors must be mounted upright. The amplifier can be muted with a single-pole switch connected to the MUTE input (pin8). This function is enabled when the switch is open. If muting is not required, solder a wire bridge across the mute terminals on the board.

Boucherot network R6-C6 is not normally required in this application, but provision has been made for it for use in other applications.

According to the manufacturers, both chips are optimalized for a load of 8 Ohm. The output power is lower when a 4 Ohm load is used or when the supply voltage is reduced. When a 4 Ohm load is used, the SPIKE protection becomes active when the supply voltage is about 27V, resulting a in a reduction of the power output to 10W. This means that it is not advisable to use loudspeaker with an impedance <8 ohm.

For best result you can expand power amplifier using BPA-200 Amplifier



Part listResistor:
R1, R3 = 1 k
R2, R4, R5 = 18k
R6 = see text
R7 = 10R, 5 Watt
R8, R9 = 22k

Capacitors:
C1 = 2.2 uF
C2 = 220 uF, 160 V
C3 = 22 uF, 40 V
C4 = 47 pF
C5 = 100 uF, 40 V
C6 = see text
C7, C8 = 100 nF
C9, C10 = 1000 uF, 40 V

Inductors:
L1 = 0.7 uH - see text

Integrated circuits:
IC1 = LM3876T

Miscellaneous:
Heat sink for IC1 <1.5 k w-1
Single-pole switch - see text



Schematic and PCB Layout LM3876
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