Class 555 amplifier circuit using 555

We know that Class D amplifiers are characterized by small size and high efficiency. Here is a simple Class D amplifier made with a 555 circuit. It uses 555 circuit to form a controllable multivibrator (multi-vibrator is a self-excited oscillator that can generate rectangular waves, also called rectangular wave generator. "Multi-harmonic" refers to the fundamental wave except the fundamental wave. In addition to the components, it also contains a wealth of high-order harmonic components. The multivibrator has no steady state and only has two transient states. During operation, the state of the circuit is automatically alternated between the two transient states. This produces a rectangular wave pulse signal, which is often used as a pulse signal source and a clock signal in a sequential circuit.), the audio signal is input to the control terminal to obtain a widened pulse (pulse-width modulation is one of the analog tape seismic recording methods). The shape of a seismic signal is changed by using a pulse wave of a stable frequency (for example, a sawtooth wave or the like) as a carrier wave, which is called pulse modulation. The seismic wave recorded on the magnetic tape is a series of square wave pulses of different widths, the width of the square wave pulse and the seismic wave. The amplitude is proportional to the amplitude, so it is called pulse width adjustment. Since this recording method reflects the characteristics of the input signal with the pulse width, it is not subject to the amplitude distortion related to the recording conditions. The influence of the change, the anti-interference ability and the signal-to-noise ratio of the tape recording and playback) signal (pictured) can basically meet the general listening requirements.

The IC 555 and R1, R2, C1 and so on constitute a 100KHz controllable multivibrator with a duty ratio of 50%. The control terminal 5 inputs the audio signal, and the 3 feet obtain the pulse signal whose pulse width is proportional to the input signal amplitude. After L and C3 are connected and filtered, the speaker is pushed.