Alarm with relay (CB21218E)

This latching alarm circuit using relays was found in American documentation. Sensors are connected in parallel.

10V Reference Source (CB21529E)
This circuit was found in an American documentation from the 60's. The transistors are from the...
10.7 MHz XTAL Oscillator (CB15006E)
This oscillator is indicated for the adjustment of FI of FM radios, having its frequency...
555 Basic Monoestable (CB3870E)
This configuration triggers an external circuit or simply an LED for time given by R1 and C1 (T =...