Dead man's switch

A dead man's switch, dead man's pedal, dead man's handle (in the United Kingdom), or simply a deadman is a device intended to take a specific action in case the human operator becomes incapacitated in some way; a form of fail-safe practice. Because the action is often to slow down or stop a vehicle, this is also sometimes known as a dead man's brake.

Related Topics:
United Kingdom - Device - Fail-safe

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In some countries, most freight elevators, lawn mowers, jet skis and snowblowers use a dead man's switch or similar mechanism that causes them to slow down and stop moving if the switch is released. Thus, if an accident occurs and causes somebody to faint or become separated from the vehicle, it will not continue down its path, potentially worsening the situation.

Related Topics:
Freight elevator - Lawn mower - Jet ski - Snowblower - Faint

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A very common use is in a locomotive; for that use, see dead-man's control.

Related Topics:
Locomotive - Dead-man's control

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Software versions of dead man's switches are used generally only by people with technical expertise, and serve several purposes, such as sending a notification to friends or deleting and encrypting data. The non-event triggering these can be almost anything, such as failing to log in for a week consecutively, not responding to an automated e-mail ping, a GPS-enabled telephone not moving for a period of time, or merely failing to type a code within a few minutes of a computer's boot. Motivations vary, depending on the individual's needs. For example, somebody in a police state may be concerned about locking up his or her data securely (or deleting it), while others may just wish to alert friends or the authorities by e-mail that something undesirable might be going on.

Related Topics:
Software - Encrypting - Log in - E-mail - Ping - GPS - Telephone - Boot

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Dead man's switch devices have also been used in suicide bombing, to trigger the explosive if the bomber is shot or overpowered. This is a fail-deadly mechanism, rather than a fail-safe mechanism.

Related Topics:
Suicide bombing - Fail-deadly

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