Half Wave Precision Rectifiers Circuit

There are several different types of precision rectifier, but it is necessary to explain what a precision rectifier actually is. In it is a simple form of circuit, a half wave precision rectifier is implemented using an op amp, and includes the diode in the feedback loop. This is the figure of the circuit.


For a low frequency positive input signal, 100% negative feedback is applied when the diode conducts. The forward voltage is effectively removed by the feedback, and the inverting input follows the positive half of the input signal almost perfectly. When the input signal becomes negative, the op amp has no feedback at all, so the output pin of the op amp swings negative as far as it can. Assuming 15V supplies, that means perhaps -14V on the op amp output.

DC to AC Inverter Using 555 IC

This is a design for AC inverter circuit. This circuit is produces an AC output at line frequency and voltage. The circuit is using 555 IC as main control. This IC is configured a low frequency oscillator, tunable over the frequency range of 50 – 60 Hz by potentiometer R4. This is the figure of the circuit.


The principle work of the circuit is the IC feeds its output that amplified by Q1 and Q2 to input of the transformer T1. A reverse is connected filament transformer with necessary step-up turns ratio. A capacitor C4 and coil L1 filter the input to T1, assuring that it is effectively a sine wave. Adjust the value of T1 to your voltage. Replacement types for Q1 are: TIP41B, TIP41C, NTE196, ECG196, etc. Replacement types for Q2 are: TIP42B, TIP42C, NTE197, ECG197, etc. The input voltage of the circuit is anywhere from +5V to +15Volt DC.