Device for detecting a defect in insulation

摘要

An electrical power supply includes DC source outputting Vm and a device that detects insulation defects in the DC source. The device includes input terminals connected to the source's terminals, impedances Z1 and Z2 connected in series between the input terminals, where Z1=Z2=Z and Vm/Imax

主权项

1. An apparatus comprising an electrical power supply device, said electrical power supply comprising a DC voltage source capable of providing a voltage sufficient to induce electrocution, said DC voltage source being configured to apply a nominal voltage Vm between terminals thereof, and a device for detecting an insulation defect of said DC voltage source, wherein said device comprises first and second input terminals connected to said terminals of said voltage source, first and second impedances connected in series between said first and second input terminals, said first and second impedances each having an impedance value Z of between Zmin and Zmax, wherein Zmin=Vm/Imax and Zmax=1.5*Vm/Imax, wherein Imax is a maximum insulation defect current defined by a standardized safety threshold, and a current-detection circuit connected between an electrical ground and an intermediate point between said first and second impedances, wherein said current-detection circuit further comprises a microcontroller comprising an input terminal configured to receive a voltage proportional to said insulation defect current originating from said intermediate point, said input terminal being connected by a third impedance to a power supply with a voltage level Vcc at least ten times lower than said voltage level of said DC voltage source, said input terminal being connected to said electrical ground by way of a fourth impedance, said microcontroller being configured to determine an amplitude of said maximum insulation defect current as a function of said voltage applied to said input terminal, wherein said third and fourth impedances each have an impedance value Zt of between Ztmin and Ztmax, wherein Ztmin=Z*Vcc/(4*Vm) and Ztmax=Z*Vcc/2 Vm.