Crystal Oscillators

The schematic above illustrates dividing a crystal oscillator signal by the crystal frequency to obtain an accurate (0. 01%) 1 second time base. Two cascaded 12 stage counters (CD4040) form a 24 stage binary counter and the appropriate bits are gated together to produce the desired division. Using a crystal of some even multiple of 2 is desirable so that one stage
Crystal Oscillators - schematic

of the counter automatically toggles every second which eliminates the need for the NAND gate and reset circuitry, however the circuit below illustrates using a crystal which is not an even multiple of 2 and so requires additional. (electronic circuit) 32. 768 kHz Oscillator using a Common Watch Crystal - Below are a couple circuits you can use to produce a 32. 768 KHz square wave from a common watch crystal. The output can be fed to a 15 stage binary counter to obtain a 1 second square wave. The circuit on the left using the 4069 inverter is recommended over the transistor circuit and produces a better waveform. The single transistor circuit. (electronic diagram) 40kHz LED Test Signal Generator - This 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses. The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals. . (designed by David A. Johnson) Crystal Controlled Oscillator (Ramon Vargas) - The RF engineer sometimes has to look for an instrument that will check a low frequency quartz crystal unit reliably and rapidly. This is a difficult piece of equipment to find and the engineer often has to consult an electronic circuits handbook for the schematic of a circuit that will perform the task. Unfortunately, there aren`t many such circuits in the technical literature currently available, and when found, they don`t always work as...

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