Emergency power off controller

This page is kept for historical interest. It may document projects or methods that are obsolete and/or no longer relevant. The information here is not kept up-to-date.

This module was part of the rack box project — which was terminated when I moved out of my first apartment.

EMG (left) with Fuse box 1 (right)

Emergency stop controller for the rack box project. Uses two 555 timers.

Details

EMG will cut the main power to the Rack box if emergency shutdown is activated. The module is powered by the 12V power supply, this supply is referred to as emergency supply. Main fuses are located on the EMG front, a green LED shows that voltage is present. If one of the fuses should burn out Main monitoring unit will signal a supply error. The big red LEDs flash when the emergency shutdown is activated. So does the strobe, but this can be terminated with a switch.

From the module front one can trigger and reset the emergency shutdown, this can also be done from the Rack status panel. Or with Serial I/O system, using the Digital emergency interface module (DEIM). EMG consists of two 555 timers, one causes the big red LEDs to flash when triggered. The other is used as a reset delay, meaning that the reset button must be pressed for five seconds.

D-Sub 9-pin

1. 12v+ in
2. 12v- in
3. 12v+ out
4. 12v- out
5. Reset switch input
6. Trigger emergency shutdown input
7. Emergency shutdown relay output
8. Emergency shutdown LED output
9. Emergency shutdown strobe output

Gallery

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  Emergency strobe

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  Emergency shutdown relay

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  Drawing of front

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  EMG (left) with Fuse box 1 (right)

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Schematic drawing