OSCILLOSCOPE CALIBRATOR
Schematic:
Notes:
The calibrator
can be used to check the accuracy of a time-base generator, as well as to
calibrate the input level of amplifiers. The calibrator consists of an NE555
connected in the astable mode. The oscillator is set
to exactly 1 kHz by adjusting potentiometer P1 while the output at pin 3 is
being monitored against a known frequency standard or frequency counter. The
output level, likewise, is monitored from potentiometer P2's center arm to
ground with a standard instrument. P2 is adjusted for 1 V pk-pk
at the calibrator output terminal. During operation, the calibrator output
terminal will produce a 1-kHz, square-wave signal at 1 V pk-pk
with about 50% duty cycle. For long-term oscillator frequency stability, C1
should be a low- leakage mylar
capacitor.
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