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32 KHz Ultra Low Power Crystal Oscillator - I have used this circuit many times when I needed a low frequency reference, which did not draw much power. With the components show, the current from a 3v battery is less than 1.2 microamps. . . Circuit by David A. Johnson P.E.-December, 2004
4 Tone Audio Oscillator - Schematic only - amateur radio construction project __ Designed by Peter Parker VK3YE
40 KHz LED Test Signal Generator - This 40 KHz 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 40 KHz modulated light signals. . . Circuit by David Johnson P.E.-February, 2002
A Crystal Heater construction project - OK, here is the circuit I used - See image below. The original National Semiconductor circuit had a 30 K resistor in series with a 400 µF cap., both in parallel with the 100 K resistor on the input of the 1st LM324 section. I found that combo to actually destabilize the operation of the controller for this particular application, so I removed them & changed the 2 µF cap in series with the 10 Megohm resistor to 5 µF.__ Bob Dengler NO6B
A Low-Frequency Crystal Controlled Oscillator - 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 __ Designed by Ramon Vargas
Crystal Controlled 1KHz Signal Generator - A while back I got an email from a Discover Circuits visitor. He needed a way to calibrate a RPM display for a big diesel engine. The engine had a tachometer output which produced 12 pulses per rotation with an amplitude of about 5v RMS. The full scale reading on the engine’s RPM speed display dial was 5, 000. . . Circuit by David Johnson P.E.-May, 2012
Crystal heater / temperature stabilization (TXCO) - OK, here is the circuit I used - See image below. The original National Semiconductor circuit had a 30 K resistor in series with a 400 µF cap., both in parallel with the 100 K resistor on the input of the 1st LM324 section. I found that combo to actually destabilize the operation of the controller for this particular application, so I removed them & changed the 2 µF cap in series with the 10 Megohm resistor to 5 µF.__ Bob Dengler NO6B
Crystal Oscillator overcomes typical Drawbacks - 08/17/98 EDN-Design Ideas - NOTE
: File has several circuits, scroll to this one. Most crystal oscillators suffer from three drawbacks: They can't drive much of a load, the duty cycle isn't adjustable, and the duty cycle drifts. The crystal oscillator in Figure 1 solves these problems. Three parallel gates drive heavy loads, the duty cycle is adjustable from 25 to 75%; and feedback minimizes the drift. Design by Ron Mancini and Jeff Lies, Harris Semiconductor, Melbourne, FL
Crystal-Based 50 Hz Generator - Here is a simple oscillator circuit that generates 50Hz frequency using a crystal. It produces alternating 50Hz pulses with 50 per cent duty cycle, which can be used in inverter circuits....__ Electronics Projects for You
Crystal-Oscillator Is Ultralow Power - EDN-Design Ideas -- 09/24/12 Build a crystal-oscillator circuit that draws only about 5 μA of current. Design by Thomas Mathews, Texas Instruments
Gated Crystal Oscillator with Very Low Power - The circuit gates the output of a continuously operating 32 KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and switching on a transistor power stage only as needed . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Harmonic VXO - I needed a quick, very temperature + frequency stable oscillator @ 50.8 MHz to test a receive mixer. Already running elsewhere on my bench, my main VHF signal generator wasn't an option. __ Contact Vasily Ivanenko
Kick start a crystal oscillator in Spice - 05/27/99 EDN-Design Ideas - Starting up oscillator circuits and getting them to maintain oscillation in a Spice simulation is difficult. Some high-frequency crystal circuits require days for the oscillation to reach steady state. This PDF has several circuits, please scroll to find this one. Design by Adam Chen, Cypress Semiconductor, Woodinville, WA
LED Test Signal Generator-40Khz - This 40 KHz 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 40 KHz modulated light signals . . . Hobby Circuit designed by David A. Johnson P.E.-February, 2002
Low Distortion Crystal Oscillator - This crystal oscillator is designed to operate with fundamental crystals with less than 1 mW dissipated in the crystal. The signal current is filtered by the crystal and develops a voltage across a capacitor with about 500 ohm of reactance. The resulting sinewave has low distortion and phase noise. A JFET buffer is included to drive lower impedance loads. Further buffering with an emitter follower and a voltage step-down transformer or matching network is recommended for driving 50 ohm loads. C3 may be reduced for larger output voltage or to allow lower drive level or it may be increased when lower output levels are desired __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Low-Frequency Crystal Controlled Oscillator - 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 __ Designed by Ramon Vargas |
