ELECTRONIC FREQUENCY-TUNING MECHANISM

摘要

This invention is concerned with an electronic mechanism for tuning musical instruments and other frequency-generating devices, by means of a meter eliminating the necessity of a trained human ear. The mechanism provides means for feeding the input signal to a preamplifier; feeding the amplified signal to a clipper; feeding the output of the clipper to both a divider and to a differentiator; thence, to a selector switch which may be used to divide or multiply the frequency of the signal by powers of two. The signal is then fed to a standard pulse generator and from there to a meter circuit which may be of the D'Arsonval-type. The readings on the meter will indicate to the operator to what extent the frequency of the musical instrument is tuned since the mechanism is already calibrated in accordance with the position of the selector switch to a specific frequency.