This charge-pump circuit quietly converts a3.3V source to5V at500 mA (figures1 and2). Nationals (www.national.com) LM4871LD power amplifier makes this design idea both possible and practical, thanks to its low output resistance, low cost, components.
This is an amplifier design made by Nelson Pass publishes at 1977. This amplifier gives out 20 watts per channel into 8 ohms, 24 watts into 6 ohms, and 28 watts into 4 ohms. The amplifier is powered from 120V AC power.
This article is for those who wants to make their own car amplifier. In this article, I will discussed the car power amplifier in 3 steps : 1.The design of audio power amplifier, 2. The design of DC-DC converter, 3. Miscellenous tips for making car power amplifier.
This kit is a quick, neat, and inexpensive way to provide a smoothed dual unregulated DC power supply suitable for powering many audio power amplifiers.
low output impedance to drive several pairs of phones the active gain stage is, almost, perfectly logarithmic, is independent of the absolute value of the pot, has excellent channel tracking, the O/P noise reduces with gain reduction.
National Semiconductor Application Notes.
Based on LM386. The circuit amplifies the input signal by 20X. A gain of 200X can be obtained by connecting a 10uF capacitor between pins 1 and 8.