D.I.Y. alarm devices

From firmware version 3.2 on (Please always update!) everything is getting easier because alarm line #1 can be pulsed by the logger. Though use these alarm devices.

Alarm devices at model side – alternatively or in addition to alarming by telemetry.

Wiring propositions which – galvanically decoupling from JLog and this way from JIVE – work with the low-active alarm lines of the logger.

Optical: LED flasher

Optical: flasher with Luxeon

Audible: interval buzzer

Wireless (433MHz)

The simplest form – not galvanically decoupled from JIVE/JLog as above: The buzzer produces a continuous tone on alarm. The positive voltage supply (as in the fig. above) is to be considered alternatively(!) – either from the logger or (better) from another voltage source, from JIVE’s BEC or an extra alarm voltage supply. If the voltage comes from the logger (he’s getting it from the diagnostic connection of the JIVE) then no more than a current of 50mA is allowed to draw. It may happen that an analog temperature sensor is disturbed by ripple from the buzzer current (not tested).

Buzzer – piezo or magnetic – keep an eye on two things: 1) Voltage requirement. Many buzzers do need clearly more than 5..6 volts to be able to produce the specified sound level. 2) Current requirement.

Why low-active? To provide that an alarm is also triggered if the device cannot see its signal source (the JLog) anymore. As long as the logger is “alive” (the JIVE-BEC supplies voltage) and the line logger–>alarm device is okay the alarm device will be kept quiet by a positive voltage. If you modify a schematic keep in mind that an optocoupler is inverting! (Not necessary to use this type of optocoupler, a lower priced PC817 w’d do well also.)