Precision Metronome/Pitch

Precision Frequency generator 1 to 999 Hz Precision Metronome 1 to 999 beats per minute. CMos IC1 and IC2B quad AND gate form a 2.4576 MHz crystal oscillator plus a 2400 times divider. IC3A provides further division by 16, delivering a 64 Hz stable frequency square wave. This frequency is multiplied (by means of Phase Locked Loop IC5, double decade divider IC4 and IC3B 4 bit binary divider) by the number set by three miniature BCD thumbwheel switches SW1, SW2 and SW3: units, tens and hundreds respectively. More: Connecting, by means of SW5, Q1 base to pin 2 of IC6, we obtain (after a 64 times division) the same frequency set by thumbwheel switches with quartz precision, and no need for a scale indicator. Volume regulation of the pitch generator is obtained trimming.

The circuit is designed to function as both a precision frequency generator and a metronome, capable of producing frequencies from 1 Hz to 999 Hz and beats per minute in the same range. The core of the circuit utilizes a CMOS configuration with IC1 and IC2B, which form a quad AND gate that is instrumental in establishing a 2.4576 MHz crystal oscillator. This oscillator is then divided down by a factor of 2400, resulting in a stable output frequency.

The output from this division stage is processed by IC3A, which further divides the frequency by 16, yielding a square wave output at 64 Hz. This stable frequency serves as a reference for the subsequent multiplication process. The frequency is then modulated by a Phase Locked Loop (PLL) IC5, which is used in conjunction with a double decade divider (IC4) and a 4-bit binary divider (IC3B). This arrangement allows for precise frequency multiplication based on the settings of three miniature BCD thumbwheel switches (SW1, SW2, and SW3), which represent the units, tens, and hundreds place values, respectively.

An additional feature of the circuit is the ability to connect SW5, which links the base of transistor Q1 to pin 2 of IC6. This connection facilitates a further division of the frequency by a factor of 64, thus providing a frequency output that retains the precision set by the thumbwheel switches without the need for an external scale indicator.

Volume regulation for the pitch generator is achieved through a trimming mechanism, allowing for fine-tuning of the output sound level. This comprehensive design ensures that the device remains versatile and user-friendly while maintaining high precision in frequency generation and tempo control.Precision Frequency generator 1 to 999 Hz Precision Metronome 1 to 999 beats per minute. CMos IC1 and IC2B quad AND gate form a 2.4576 MHz crystal oscillator plus a 2400 times divider. IC3A provides further division by 16, delivering a 64 Hz stable frequency square wave. This frequency is multiplied (by means of Phase Locked Loop IC5, double decade divider IC4 and IC3B 4 bit binary divider) by the number set by three miniature BCD thumbwheel switches SW1, SW2 and SW3: units, tens and hundreds respectively. Connecting, by means of SW5, Q1 base to pin 2 of IC6, we obtain (after a 64 times division) the same frequency set by thumbwheel switches with quartz precision, and no need for a scale indicator. Volume regulation of the pitch generator is obtained trimmi 🔗 External reference