Mini Amplifiers | Electronic Project Circuits

Posts Tagged ‘Mini amplifiers’

Amplifier circuits with transistors 2SC1815

Generally in work learning of transistor. We can divide work period of transistor be 3 the period. For example period cut off be transistor stop work at this period have no bass current (lb) and collector current (lc) the period is full be intermittently at current flow through with full speed ahead until reach the condition is full and the trend will don’t flow increase back and forth the reed that the this and the period active be intermittently at transistor work Bias current. By we can seek expansion ratio value current thus in using transistor power amplifier as a result will very the circuit work during active. By we will live expansion ratio way value current of transistor.
When there is a signal Input feed come in change C1 for filter take especial sound signal only go to feed give with Q1 at a B pin be the expansion first. Which very the circuit enlarges like small hill computer not the stump have R1 and R2 build divide bias voltage give Q1 by have a signal output at collector pin (C) a signal has that this still not enough. Power then must induce to enlarge with Q2 and Q3 again. Which Q2 and Q3 each other be darlington circuit be the lead transistor 2 pcs. at have alike property comes to each other will get expansion rate increases. From that time a signal that enlarged reach a loudspeaker SP1 make a noise come out.

Be the first to comment - What do you think? Posted by admin - July 26, 2010 at 6:42 am

Categories: Power Amplifier Tags: c1815, Low watt amplifier, Mini amplifiers, simple transistor amplifier circuit

Low impedance mini amplifier

This circuit can apply to signal sound source that has low impedance , such as from 4-16 ohm size loudspeakers or telephone earphone that use to replace , Micro phone. If use a loudspeaker replaces the rapidity will enough in sound checking that has been born from walking. The output this can feed reach input of high power amplifier the other next.

Be the first to comment - What do you think? Posted by admin - August 1, 2009 at 10:56 am

Categories: Power Amplifier Tags: Low impedance amplifier, Mini amplifiers

2-TRANSISTOR AUDIO AMPLIFIER by BC108

A simple two-stage amplifier. Use any general-purpose NPN with high gain. It will drive low impedance headphones directly. A speaker will probably require further boost.
An old HAM handbook I found in the school library many years ago.

Source: http://www.geocities.com/tomzi.geo/index.htm