A security alarm system for a vehicle having an alert device, the alert device including an audible alert device, and the security alarm system comprising an intrusion detector for detecting an intrusion event on the vehicle; and an alert controller for controlling the alert device, wherein the alert controller generates an activate instruction to activate the alert device responsive to the intrusion event detected by the intrusion detector and generates a deactivate instruction to deactivate at least the audible alert device after a first predetermined time interval from the generation of the activate instruction, and wherein the alert controller further prevents a generation of an activate instruction of at least the audible alert device during at least a second predetermined time interval after the generation of the deactivate instruction.

A pickup indicator arrangement for a collection receptacle for deposit of items for delivery is described in which an on-off light is turned on by operation of a switch when the pickup is made. A timer turns the display off after a predetermined delay to ready the display for the next pickup.

A method and apparatus for theft prevention and/or recovery of stolen drink dispensers generally comprises the provision of an anti-theft device within a drink dispenser machine for detecting illegitimate movements of the machine and thereafter disabling the machine's operation. The disruption of operation is accompanied by an indication on the machine's display panel alerting the possessor of a general failure and requesting the placement of a maintenance service call. Concurrently, an innocuous indicator is also activated for alerting the responding service technician to the possibility that the dispenser machine under repair is stolen.

A perimeter monitoring system is arranged to detect passage across a perimeter of an area. The system primarily includes an emitter, a retroreflector, a detector and an alarm. The emitter provides a modulated visible laser beam. The retroreflector is arranged to direct the beam along a segment of the perimeter and return the beam along the segment. The detector includes a device that blocks reception of light outside an angle of less than 5 degrees. One or more local or remote alarms are activated in response to the signal. For example, a remote alarm is located on the inside of a residence window where it is activated by another visible laser beam. Alignment of the peripheral monitoring system is less costly and false alarms are less likely than with known systems.

A transient signal suppressor (10) for use in a controls system which is adapted to respond to a change in a physical parameter whenever it crosses a predetermined threshold value in a selected direction of increasing or decreasing values with respect to the threshold value and is sustained for a selected discrete time interval. The suppressor (10) includes a sensor transducer (12) for sensing the physical parameter and generating an electrical input signal whenever the sensed physical parameter crosses the threshold level in the selected direction. A manually operated switch (30A, 30B) is provided for adapting the suppressor to produce an output drive signal whenever the physical parameter crosses the threshold value in the selected direction of increasing or decreasing values. A time delay circuit (40,42) is selectively adjustable for suppressing the transducer input signal for a preselected one of a plurality of available discrete suppression time and producing an output signal only if the input signal is sustained for a time greater than the selected suppression time. An electronic gate (25) is coupled to receive the transducer input signal and the timer output signal and produce an output drive signal for energizing a control relay (33) when transducer input is a non-transient signal which is sustained beyond the selected time interval.