Browse Prior Art Database

Visual Halt Alarm

IP.com Disclosure Number: IPCOM000083770D
Original Publication Date: 1975-Jul-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Muller, KJ: AUTHOR

Abstract

Many data processing systems include an alarm that produces an audible signal when the system stops. In some situations (e.g., a very noisy environment) this may not be adequate to attract the attention of a system operator.

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Visual Halt Alarm

Many data processing systems include an alarm that produces an audible signal when the system stops. In some situations (e.g., a very noisy environment) this may not be adequate to attract the attention of a system operator.

The circuit illustrated can be easily connected to a system that has an audible alarm. It will provide a high-intensity stroboscopic flash that will illuminate the area and attract the attention of an operator, even when he is not specifically looking for it.

The coil CL1 which controls normally open relay RLY1 is connected to the coil of the audible alarm. When the alarm is not sounding, current flowing in CL1 will keep RLY1 closed so current will not flow through the coil CL2 which controls normally open relay RLY2. The voltage +V will be dropped across resistor R.

When the audible alarm sounds, a decrease in the CL1 current will allow RLY1 to open. Current flow through CL2 will cause RLY2 to close, thereby completing the circuit through the ground trigger of the strobe light and cause the light to flash.

The frequency of flashes will depend upon the nature of the audible alarm (that is, whether it is a constant sound or an intermittent one) and upon the value selected for capacitor C, as well as upon the specifications of the strobe light.

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