This circuit is from a 1968 publication. Here we have several types of resistive sensors with individual adjustments triggering a single SCR. Power depends on the type of sound device to be triggered.
Figure below shows the basic configuration of a ringoscillator using CMOS Iogic. The frequency...
This circuit was obtained from an Analog Devices manual from the 90's. The integrated circuit is...
This low current solenoid driver was found in an ancient American documentation. The solenoid must be...