Interlock (engineering)

An interlock is a welcome and necessary part blocking. For mechanical locking bolt can be used. In electrical engineering, a locking means the intentional blocking of a switching device by an Other. Here also, the English technical term interlock is used.

Tasks

A lock to prevent unwanted conditions, processes or events. It should be avoided that mistake to take certain actions that can cause damage to the environment, technical equipment or danger to life and limb. To release a lock is usually conscious action necessary. A lock must be designed so that it can not accidentally be overcome, at the same time may not be able ( too light ) from being accidentally turned on the lock itself. The latter could lead to failure of machinery and equipment.

Operation

Latches are mechanically, electro- mechanically, electrically, pneumatically, hydraulically or by means of software possible. A suitable mechanical locking mechanism or a contact prevents a mechanical or a switching command is activated or executed. Many electrical devices may for example not be turned on when the emergency stop switch is pressed.

In electrical engineering, certain features are locked against each other: a separator may only be opened if the circuit breaker has been switched off. Conversely, a separator may only be closed when the power switch is still "off" (certain exceptions are allowed). Here the disconnector is locked against the circuit breaker. With the circuit breaker closed prevents an auxiliary contact (NC) of the same in the control circuit (before the off - coil) of the disconnector that opening command can access the separator.

In many modern control a latch on Logical operations is realized.

Examples

• A mechanical locking can be found as mentioned in modern emergency stops. The securing of a weapon is a type of locking dar. this case, the deduction is by and locked against the fuse.
• A hand brake is mechanically protected against accidental release.
• Electrical interlocks are found in various devices and controllers. So you may in an engine that can run right and left around, not able to turn both directions at the same time - here is the left- to right-handed rotation locked and vice versa.
• At traffic lights the red lamp is locked against the green, as well as the lights of the individual streets are locked against each other ( it may not be all the traffic lights at the same time to "green " position).