A guard door monitoring system comprising a guard door monitoring module for monitoring a state of a guard door to a safety area. The guard door monitoring system also comprises a control unit, configured to analyze a guard door signal generated by interaction between an actuator and a sensor, and to control a machine or system located in the safety area depending on the guard door signal. A locking device with a main body and a locking lever arranged on the main body is additionally provided. The locking lever can be moved relative to the main body from a release position into a blocking position in which the locking lever prevents the interaction between the actuator and the sensor, wherein the locking device comprises a receptacle for a lockable securing part, which, when introduced into the receptacle, keeps the locking lever in the blocking position.

An electronic lockset with a radio frequency harvesting circuit. In one embodiment, the electronic lockset includes a mechanical locking portion movable between a locked position and an unlocked position. One or more energy consumption devices are provided that actuate the mechanical locking portion between the locked position and the unlocked position. A rechargeable battery provides electrical power to the energy consumption devices. A radio frequency (RF) transmitter and RF energy harvesting circuit are used to wirelessly recharge the battery. Typically, the RF transmitter is configured to transmit at a predetermined frequency. The RF energy harvesting circuit is tuned to the predetermined frequency and is electrically coupled with the rechargeable battery to recharge the battery.

The described embodiments relate to a locking mechanism for securing a housing of a computing device. More specifically, the disclosed embodiments are configured to both secure the housing of the computing device closed and to provide a means for securing the desktop computing device to a stationary object such as a desk. The locking mechanism can be two separable locking bodies configured to be received by separate openings in a housing of the computing device. Once the separate openings receive both locking bodies, a locking device can engage both pieces of the locking mechanism to lock both pieces to each other and to the housing.