| 摘要 |
<p>The stand-by circuit (SBC) comprises an input terminal (a) intended to be connected to the input of the driver circuit (IC), a capacitor (C), first and second current generators (G1, G2) selectively connectable to the capacitor (C), a first comparator circuit (C1) which when the signal (Vin) applied to the said input terminal (a) exceeds a predetermined threshold (Vso) connects the capacitor (C) to the first current generator (G1) to charge the said capacitor (C) at constant current, and when the said signal (Vin) is less than the said threshold (Vso) uncouples the capacitor (C) from the first current generator (G1) and connects it to the second generator (G2) in such a way as to discharge it at constant current, and a second comparator circuit (C2) which allows current to be supplied to the driver circuit (IC) when the voltage on the capacitor (C) exceeds a preestablished threshold (Vs2). <IMAGE></p> |
