The TMD-90 Supervised Passive Infrared Motion Detector is a passive infrared (PIR) motion detector with a built-in supervised, digitally-coded radio transmitter designed for security applications.

The PIR detects motion in its detection pattern by measuring the infrared emission levels of objects that it sees. If the infrared levels change quickly, as when a person moves across the detection pattern, the PIR will recognize the change as an intrusion.

A selectable pulse count circuit controls the PIR’s triggering of the transmitter. As a person moves across the detection pattern, the PIR registers one pulse as each finger of the detection pattern is crossed. The TMD-90 counts these pulses. When the selected number of pulses occur during the selected time, the PIR will trigger the transmitter, sending an alarm signal. A lockout timer prevents the transmitter from triggering more often than once every 2 minutes when constant motion is detected. The pulse counting and timing options are selected with the OPTION switch.

The unit is supervised for low battery, alarm and status reporting. The TMD-90 is compatible with any Linear SX format supervised security receiver. The transmitter sends hourly status reports. A test report can be sent by pressing the test button.

Coding switches are not required or used in this transmitter. Each transmitter is pre-coded at the factory to a unique code. With the SX format, there are more than sixteen million codes possible.

The transmitter is powered by four AA 1.5-volt alkaline batteries (included) and can power the unit for up to 5 years. When the battery voltage gets low, a low battery report is sent to the receiver with any alarm, test or status report.