Showing posts with label by. Show all posts
Showing posts with label by. Show all posts

Thursday, November 13, 2014

LED Sound level display circuit by using IC LM3915

This circuit is about audio sound level LED display, indicator, monitor or you can say it “Audio VU (Volume Unite) Meter”.
This is a simple audio sound level LED display circuit diagram. The circuit is completely  based on  a single ic LM3915 from National Semiconductor. The LM3915 is a monolithic integrated circuit. It displays the audio sound level in terms of 10 LEDs and providing a logarithmic 3 dB/step analog display.

Audio sound level display circuit diagram


Fig: Circuit diagram of sound level display using ic LM3915
The audio sound level LED display circuit can operate from a single supply 3V to 25V. But I  suggest to use 9-12V. LED brightness can be controlled with a single pot( variable resistor) as shown 10K ohm in the circuit. Connect the audio input signal in Pin-5 of LM3915 from output of a audio device like output of audio amplifier or any other source.
The Pin-9 of LM3915 is to select dot or bar mode display. To make the circuit moving dot display instead of a bar graph display disconnect the Pin-9 from +V.
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Sunday, October 5, 2014

PIC Dual Temperature Meter by PIC16F628

PIC

This is extremely simple to build PIC Temperature meter that allows to measure temperature in two different locations at the same time. Never before such a useful and powerful circuit could be built with so little components and yet provide endless possibilities. This is all possible thanks to the use of PIC16F628 microcontroller and 2×16 character LCD display that act like a small computer which can be customizable thanks to upgradeable hex firmware.

Presented PIC temperature meter uses two very exciting DS18S20 digital temperature sensors that come in convenient TO92 package. Unlike regular sensors where temperature readings are passed as varying voltage, DS18S20 passes temperature information in a digital format as data. This brings many new possibilities and enables to pass temperature information over much longer distances just over a two wire cable. With this temperature can be measured in different locations at the same time and away from the main circuit board. With regular sensors which rely on the varying voltage cables must be as short as possible because longer wires introduce stray resistance that bring unreliable readings.

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Friday, August 22, 2014

25W MONO AMPLIFIER WITH MUTE ST BY

Features:
  • WIDE SUPPLY VOLTAGE RANGE (UP TO
  • 50V ABS MAX.)
  • SPLIT SUPPLY
  • HIGH OUTPUT POWER:
  • 25W @ THD =10%, RL = 8Ω, VS = +20V
  • NO POP AT TURN-ON/OFF
  • MUTE (POP FREE)
  • STAND-BY FEATURE (LOW IQ)
  • FEW EXTERNAL COMPONENTS
  • SHORT CIRCUIT PROTECTION
  • THERMAL OVERLOAD PROTECTION


DESCRIPTION:

The TDA7261 is class AB Audio power amplifier assembled in the Multiwatt package, specially de- signed for high quality sound application in mono TV chassis.

Circuit Diagram:
25W MONO AMPLIFIER WITH MUTE/ST-BY

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