Dilshan R Jayakody’s Web Log

TDA7052A is an audio power amplifier designed for use in low voltage battery-powered equipment. Compare with the popular LM386, TDA7052A is not so popular among DIY electronic enthusiasts.  Final view of the finished amplifier with speaker.   Using the Bridge Tied Load principal, this IC delivers an output power of 1.2W into an 8Ω load with, 6V power supply.   The most striking feature of this amplifier is the minimum external component count. This IC only needs two external capacitors to build a functional audio amplifier.   The gain of the amplifier is fixed internally at 40dB. The amplifier got, short-circuit protection, requires no external heatsinks, and not producing any switch on/off click sound(s).    Although this is an old amplifier IC, it is still available to purchase in many local and online stores. Compare with the other low-power AF power amplifier ICs, TDA7052 is a little expensive in the local market. Although it is costly, I use this IC ...

USB Morse Keyer is a microcontroller-based auto keyer project with following features: USB / straight key / iambic key inputs. Support for both standalone and USB operating modes. 64-character USB typeahead buffer and 6-character Morse key typeahead buffer. Support 5, 10, 15 WPM. 6-page message memory. 1W Audio output. Audio and PTT output interfaces. 32 character display  Final view of the USB auto keyer. The USB interface of this unit is designed to work with most of the operating systems. It emulates a virtual serial terminal to transfer keystrokes to the keyer. In most of the operating systems, this interface works without installing any additional device drivers. To submit keystrokes user can use any serial terminal software such as PuTTY , Hyper Terminal , Minicom , etc. This keyer is designed to work with 7V to 16V DC input voltage. The most recommended working voltage is 9V. The bottom side of the USB auto keyer. To reduce the dimension of the P...

" Musical trees " is a part of creative art installation and this project is capable to produce different audio tones by detecting a human touch to its attached plants. The existing version of this driver is capable to monitor 8 plants and produce different sounds for each plant. A prototype version of "Magic Tree" project with 2 plant samples. This project is built around PIC16F628A 8-bit microcontroller and PT2399 echo processor IC. To drive the sensor electrodes we use pair of CD4011 quad 2-input NAND gate ICs. This prototype uses TDA7052 1W audio amplifier IC to drive the speaker(s). The existing firmware of PIC16F628A is designed to produce tones in between 155Hz to 1244Hz and this range can be changed by modifying the supplied firmware source code. In this design, the PT2399 echo processor IC is used to get the more natural (/ deep) sound effect by adding some reverberation to the output. Schematic and firmware of this project are available to ...

Electric Fences are designed to create an electrical circuit when touched by person (or animal). The circuits proposed in this article release 10kV electrical pulses to the fence-line and monitor the line status. This entire system is design to drive using 25V (5A) single-rail DC power source (using 5A power supply unit or pair of 12.6V Lead-Acid batteries). Main controller of this system is Microchip PIC12F675 – 8bit microcontroller. All the line monitoring, pulse generation and alarm system controlling is performed by this microcontroller. Some of the most notable features of this system are built-in audible alarm system, contactless fence line monitoring system, Support for wide range of step-up transformers (up to maximum of 10kV) and compact 10cm × 10cm PCB design. This system use standard electronic components (through-hole components) and SMD components in this provided PCB layout. All the project documents, schematics, PCB designs and firmware source codes are available...

This is simple PIC microcontroller base project to generate Morse codes using standard PS/2 keyboard. This project based on Microchip’s PIC16F73 microcontroller and National semiconductor’s LM386 audio power amplifier. Software for PIC microcontroller is written using MikroC and all the source codes, schematic diagrams and other documents are available to download at here . In this project we choose PIC16F73 because of it’s 4KW (KWords) program memory, it is possible to replace this MCU with any suitable MCU which having 4KW (or more) flash memory. (For example Atmel AT89C4051-24SJ with different source code, Microchip PIC16F648 with some minor changes in source code, etc) Audio power amplifier of this project is based on National Semiconductor’s LM386. We choose LM386 because of its lower power consumption and compactness. User may also replace this module with suitable power amplifier (for example Philips TDA7052, TDA8551, National’s LM4906, etc.) PIC16F73 software is develop...