circuit coll

Non-Switching Amplifiers

Most of the distortion in Class-B is crossover distortion, and results from gain changes in the output stage as the power devices turn on and off. Several researchers have attempted to avoid this by ensuring that each device is clamped to pass a certain minimum current at all times. This approach has certainly been exploited commercially, but few technical details have been published. It is not intuitively obvious (to me, anyway) that stopping the diminishing device current in its tracks will give less crossover distortion .

Current-Drive Amplifiers

Almost all power amplifiers aspire to be voltage sources of zero output impedance. This minimizes frequency-response variations caused by the peaks and dips of the impedance curve, and gives a universal amplifier that can drive any loudspeaker directly.

The opposite approach is an amplifier with a suffi ciently high output impedance to act as a constant-current source. This eliminates some problems – such as rising voice-coil resistance with heat dissipation – but introduces others such as control of the cone resonance. Current amplifiers therefore appear to be only of use with active crossovers and velocity feedback from the cone . It is relatively simple to design an amplifier with any desired output impedance (even a negative one), and so any compromise between voltage and current drive is attainable. The snag is that loudspeakers are universally designed to be driven by voltage sources, and higher amplifier impedances demand tailoring to specifi c speaker types

Description

                  Before three weeks i am introduced  inverter circuit diagram but the circuit not included ac to inverter switching part so today i introducing a 230 Volt Ac to inverer switching circuit diagram .

Circuit showing a inverter switching  . Here i have used  bc 558 ,BC 548 and a relay for making this circuit . 230 volt connected to the base of the transistor Q1.When the power is ON positive volt coming to the base of the transistor so the relay circuit is open and load working in 230 V AC .When the power is OFF ground voltage coming to the base of the transistor so the Base of the Q2 is positive there for the   relay circuit closed and load working in inverter input .Part list and applications are showing below.


Part List

Component No:	Value	Usage
R1	100KΩ	Emitter Load
R2	10K Ω	Base Biasing
R3	180KΩ	Current Limiting
Q1	BC558	Switching
Q2	BC548	Switching
D1	IN4007	Relay Balancing
RL1	12 V	Inverter Switching

Applications


* Inverter Switching 


* AC Switching

ADJUSTABLE 1.5A STEP DOWN 1.5MHz SWITCHING REGULATOR ELECTRONIC DIAGRAM