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Ultra-High Fidelity High Power Amplifier Reference Design

The LME49830 EF125WT1 amplifier PCB module showcases National Semiconductor’s LME ultra-high fidelity power amplifier input stage ICs (drivers). The LME49830 is a fully complementary bipolar 200V input stage IC with 56mA (typical) of output current that has been optimized for audio applications. With 56mA of current drive, the IC can drive numerous power transistors to achieve high levels of output power. The LME49830’s ultra-low distortion and low-noise, combined with a user adjustable compensation scheme results in a tightly controlled, but highly dynamic listening experience.... [read more]

Headphone Amplifier

High Quality unit. No need for a preamplifier.... [read more]

Motorola Hi-Fi power amplifier

This is a very simple, low cost, Hi-Fi quality power amplifier. You can build it 5 ways, like it’s shown in the table (from 20 W to 80 W RMS).... [read more]

USB Powered Mobile Phone Battery Charger

This simple circuit can give regulated 4.7 volts for charging a mobile phone. USB outlet can give 5 volts DC at 100mA current which is sufficient for the slow charging of mobile phones. Most of the Mobile Phone batteries are rated 3.6 volts at 1000 to 1300 mAh. These battery packs have 3 NiMh or Lithium cells having 1.2 volt rating. Usually the battery pack requires 4.5 volts at 300-500 mA current for fast charging.... [read more]

4W FM Transmitter

Stabilised tendency of catering: Vcc=12~16V Frequency of emission: 88~108MHz Consumption: 100~400mA... [read more]

Whistle On - Whistle Off

This is an extension of the CMOS toggle flip flop circuit with the addition of two bandpass filters and condenser microphone so the relay can be toggled by whistling at it. The condender mic used is a PC board mount Radio Shack #270-090C.... [read more]