| 摘要 |
Circuit making it possible to enhance the performance, in particular the accuracy, and to obtain small durations. It includes a main timer TP for performing a count following reception of a supply Va, 14-7 and a control 5, SC, a back-up supply AS automatically connected in the event of a cut-off, and an auxiliary timer TA with drop-out, of duration Tc, to maintain the operation of the main timer or to stop it according as the duration of cut-off is less than or greater than Tc. This control SC is produced by a bistable circuit CB controlled by the discharging of an RC circuit above a particular threshold. The invention applies to electromagnetic relays K. <IMAGE>
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