Self-powered Sine to Square wave Converter

Introduction:
Converts sine to square waves without a power-source.Useful as a test instrument for audio purposes.

Circuit diagram:

Parts:

R1--------------1M 1/4W Resistor

R2--------------100K Linear Potentiometer

C1,C2-----------100µF 25V Electrolytic Capacitors

C3--------------0nF 63V Polyester Capacitor

D1,D2-----------1N4148 75V 150mA Diodes

IC1-------------4069 Hex Inverter IC

Device purpose:

This circuit is intended to provide good square waves converting a sine wave picked-up from an existing generator. Its main feature consists in the fact that no power-source is needed: thus it can be simply connected between a sine wave generator and the device under test.
The input sine wave feeds a voltage doubler formed by C1, C2, D1 & D2 that powers the IC. IC1A amplifies the input sine wave, other inverters included in IC1 squaring the signal and delivering an output square wave of equal mark/space ratio and good rise and fall times through the entire 20Hz-20KHz range.

Notes:

• Best performances are obtained with an input sine wave amplitude from 1V RMS onwards.
• Output square wave amplitude is proportional to input amplitude.
• Minimum sine wave input amplitude needed for good performance: 750mV RMS.
• Output square wave amplitude with 1V RMS input: 3V peak to peak, with R2 set at max.
• Minimum output square wave amplitude: 2V peak to peak, with R2 set at max.
• Substituting the two silicon diodes with germanium types (e.g. AA118, AA119), the minimum input threshold can be lowered.

Share on Google Plus

About sNova

This is a short description in the author block about the author. You edit it by entering text in the "Biographical Info" field in the user admin panel.