Found in a 1990s US publication, this alarm circuit detects when a light beam is interrupted. Optical resources may be used for the sensor and instead of the alarm a relay may be used.
This basic 100 kHz oscillator is suitable for use in calibration. We found it in documentation from the...
Found in a 1968 EEE, this circuit accepts frequencies from 1 to 1000 Hz and control voltages from 0.1 to...
National Semiconductor suggests the circuit shown in the figure for amplifying signals from two...