Dilshan R Jayakody’s Web Log

The LM386 is a low-voltage audio power amplifier designed by National Semiconductor , which is now part of Texas Instruments . Introduced in 1983, it has been widely used in various audio applications, such as amplifying signals in small radios, portable speakers, and other low-power audio equipment. This compact device integrates all the essential components of a basic audio amplifier circuit, including an internal biasing network, an input stage, and an output driver. It operates within a supply voltage range of 4V to 12V, making it ideal for driving small speakers while consuming minimal power. A standout feature of the LM386 is its adjustable gain, which can be varied between 20 (26dB) and 200 (46dB) using external components. Assembled LM386 power amplifier. Although modern Class-D amplifiers offer higher efficiency and greater power output, the LM386 remains a viable solution in certain applications due to its straightforward design, low cost, ease of assembly (thanks to i...

Simtelic Music Module is a user-programmable module that uses RTTTL data to store and play melodies. EL0003 - Programmable music module. RTTTL , which stands for Ring Tone Text Transfer Language , was created to provide a simple, text-based format for sharing ringtones on early mobile phones. Developed by Nokia , it quickly became popular due to its compact size and compatibility with text messaging services. This format allowed users to easily exchange custom melodies without needing specialized software or data connections. RTTTL is a human-readable data format where each ringtone is represented as a sequence of notes, durations, and optional settings. According to Simtelic naming conventions, this module is identified as EL0003 and is available for purchase online. Top view of the EL0003 module. This module is built around a 32-bit MCU, a 2Kbit EEPROM, and a CH340 USB bus conversion chip. It is compatible with the latest Windows and Linux-based PCs. The module is user-fr...