An input-voltage-off detection apparatus includes a voltage adjustment unit, a time delay unit, a voltage clamp unit, an auxiliary voltage discharge switch unit and an isolation notification unit. The voltage adjustment unit receives an input voltage. The time delay unit utilizes the input voltage to generate a direct current voltage. After the input voltage is cut off, the direct current voltage stored in the time delay unit discharges to the voltage adjustment unit. When the direct current voltage reduces to a predetermined voltage, the auxiliary voltage discharge switch unit is turned on, so that an auxiliary voltage winding sends a working voltage to the isolation notification unit. After the isolation notification unit receives the working voltage, the isolation notification unit notifies an electronic apparatus that the input voltage is cut off.

An input-voltage-off detection apparatus includes a voltage adjustment unit, a time delay unit, a voltage clamp unit, an auxiliary voltage discharge switch unit and an isolation notification unit. The voltage adjustment unit receives an input voltage. The time delay unit utilizes the input voltage to generate a direct current voltage. After the input voltage is cut off, the direct current voltage stored in the time delay unit discharges to the voltage adjustment unit. When the direct current voltage reduces to a predetermined voltage, the auxiliary voltage discharge switch unit is turned on, so that an auxiliary voltage winding sends a working voltage to the isolation notification unit. After the isolation notification unit receives the working voltage, the isolation notification unit notifies an electronic apparatus that the input voltage is cut off.

An apparatus, system, and method for managing an electrostatic charge of a workpiece are disclosed. The method comprises coupling an electrostatic voltmeter to a conductor, coupling a charge-adjustment system to the conductor, and coupling the conductor to the workpiece. A level of charge in the workpiece is adjusted, via the conductor, with the charge-adjustment circuit and a voltage of the workpiece is monitored, via the conductor, with the electrostatic voltmeter. A controller may be used to adjust the charge on the workpiece based upon the monitored voltage.

An apparatus, system, and method for managing an electrostatic charge of a workpiece are disclosed. The method comprises coupling an electrostatic voltmeter to a conductor, coupling a charge-adjustment system to the conductor, and coupling the conductor to the workpiece. A level of charge in the workpiece is adjusted, via the conductor, with the charge-adjustment circuit and a voltage of the workpiece is monitored, via the conductor, with the electrostatic voltmeter. A controller may be used to adjust the charge on the workpiece based upon the monitored voltage.

A floating apparatus for alerting people of the presence of voltage in water. When the floating apparatus is placed in water and in an active state, it detects when at least a threshold level of voltage is present in the water and generates an alert signal in response to detecting the threshold level of voltage is present. The floating apparatus may detect the threshold level of voltage is present without requiring that a ground wire be connected between an electrical circuit of the floating apparatus and a fixed structure exterior of the water such as soil surrounding the water.

An electrical safety monitor is provided. The electrical safety monitor may include a housing having a face. The electrical safety monitor further includes a plurality of line inputs for hardwiring a plurality of electrical connections. The electrical safety monitor further includes a plurality of test points with each of the test points corresponding to one of the line inputs, each of the plurality of test points accessible at the face of the housing. The electrical safety monitor further includes a line monitoring circuit having a plurality of light indicators and configured to produce light if voltage exists between any two of the line inputs to thereby indicate presence of voltage to a user. The electrical safety monitor further includes illumination areas associated with each of the test points, wherein each of the illumination areas is provided light by one or more of the plurality of light indicators.

An electrical safety monitor is provided. The electrical safety monitor may include a housing having a face. The electrical safety monitor further includes a plurality of line inputs for hardwiring a plurality of electrical connections. The electrical safety monitor further includes a plurality of test points with each of the test points corresponding to one of the line inputs, each of the plurality of test points accessible at the face of the housing. The electrical safety monitor further includes a line monitoring circuit having a plurality of light indicators and configured to produce light if voltage exists between any two of the line inputs to thereby indicate presence of voltage to a user. The electrical safety monitor further includes illumination areas associated with each of the test points, wherein each of the illumination areas is provided light by one or more of the plurality of light indicators.

An electrical safety monitoring system is provided. The system includes an analog circuit having line inputs for hardwiring an L1, an L2, an L3, and a GND three-phase connections, the analog circuit configured to monitor if voltage exists between any two of the line inputs, a heartbeat circuit electrically connected to the analog circuit to provide a heartbeat signal indicative of voltage present on any of the line inputs, an isolated voltage source electrically connected to the heartbeat circuit to power the heartbeat circuit with a VDC+ and a VDC−, and a logic circuit in operative communication with the heartbeat circuit for monitoring input from the heartbeat circuit and decoding the input from the heart beat circuit. The isolated voltage source may be supplied by a programmable logic controller (PLC) and the logic circuit may be implemented within the same PLC as a function block.

An electrical safety monitoring system is provided. The system includes an analog circuit having line inputs for hardwiring an L1, an L2, an L3, and a GND three-phase connections, the analog circuit configured to monitor if voltage exists between any two of the line inputs, a heartbeat circuit electrically connected to the analog circuit to provide a heartbeat signal indicative of voltage present on any of the line inputs, an isolated voltage source electrically connected to the heartbeat circuit to power the heartbeat circuit with a VDC+ and a VDC−, and a logic circuit in operative communication with the heartbeat circuit for monitoring input from the heartbeat circuit and decoding the input from the heart beat circuit. The isolated voltage source may be supplied by a programmable logic controller (PLC) and the logic circuit may be implemented within the same PLC as a function block.

An absence of voltage indicator has an isolation circuit, an FM modulator attached to the isolation circuit, a reference oscillator, and a mixer attached to the reference oscillator and the FM modulator, wherein the output of the mixer is the difference of the two signals. In one embodiment, the FM modulator includes a variable capacitor which varies in response to a voltage in parallel to a fixed capacitor and an inductor in parallel to the capacitors.