| 摘要 |
The invention relates to a device comprising: - an analog/digital convertor 100 converting an analog datum representing the current flowing through the load into a digital current datum; - a time bases generator 200 delivering on a plurality of outputs clocking signals Q1-Q9 of different periods; - a decoder-selector circuit 300 receiving, on the one hand, the digital current datum and, on the other hand, the said clocking signals and capable of selecting and delivering on an output one of the said clocking signals as a function of the interval of values within which the output datum from the convertor is contained; - an incrementation/decrementation control circuit 410 receiving the digital current datum and delivering as output a control signal which differs depending on whether the said digital current datum is above or below a specified current threshold value; - an incrementor/decrementor circuit 400 operating in accordance with the clocking signal delivered by the selector-decoder circuit 300 and the control signal delivered by the control circuit 410 in order to increment or decrement a thermal state register for the load; and - a comparator circuit 500 comparing the contents of the thermal state register with at least one threshold value in order to control an operation for protection and/or signalling. The invention also relates to a method implemented by the device. Application to the thermal protection of loads such as asynchronous motors. <IMAGE>
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