Dilshan Jayakody writes: This is simple Colpitts oscillator to test commonly available passive crystals which range between 2MHz to 27MHz. This unit must connect to an oscilloscope and/or frequency counter to get the frequency of the crystal. This circuit is design to work around 9V to 12V DC power source. Both 2SC930 transistors can replace […]
Tag Archives: frequency
Crystal oscillator frequency pulling
KF5OBS writes: This video briefly explains how to influence a crystal oscillator’s frequency by introducing reactive elements such as trim capacitors and inductors. This example uses a very simplistic Pierce oscillator and a crystal ins series resonance.
Mains frequency display
fowkc has just published his latest project the mains frequency display: I wanted to make a display that could show the mains frequency to 3 decimal places. I’d be using the same seven-segment display modules that I used in my UNIX clock, so all I had to do was design the part that would work out the […]
1Hz to 10MHz frequency meter using ATtiny2313
1Hz to 10MHz frequency meter using ATtiny2313: This AVR-based Frequency Meter is capable of measuring frequencies from 1Hz to 10MHz with 1 Hz resolution. The hardware of this project consists of seven 7-segment displays, AVR ATtiny2313 uController, and a few transistors and resistors. The AVR counts input pulses for a precise 1 second interval (generated […]
High precision decade frequency generator
Jbeale designed a high precision decade frequency generator based on a 26Mhz ovenized oscillator with stability of +-1 part-per-billion, or +-0.0000001%. The generator is controlled with a PIC16f1823 microcontroller, which provides interface and frequency division. Firmware, PCB and schematic are uploaded on his site. He also provided a link to Tom V.B. impressive site that […]
Constant temperature crystal oscillator
Crystal oscillators generate pretty accurate frequencies, but the output varies a bit depending on the operating temperature. The crystal oven heats a crystal to a constant temperature to get the most accurate and consistent frequency possible. Via Hack a Day.