Patent ID: 9480124
Filing Date: 2016-10-25
CPC Classification: H05B,Y02B

Claim Text:
1. A single-string over power protection device for a display, comprising: a voltage detection unit, with an input terminal being connected to a voltage acquisition component in the circuit of a single-string light bar at both ends, for obtaining the voltage across the voltage acquisition component; an integral unit, with an input terminal being connected to the output terminal of the voltage detection unit, for performing an integral transform on the voltage obtained; a comparison unit, which is connected to the output terminal of the integral unit, for comparing the voltage after the integral transform with a reference voltage determined by system parameters, so as to output an effective over voltage signal when the voltage after the integral transform is higher than the reference voltage; and a latch unit, connected to the comparison unit to lock an output standby signal according to the effective over voltage signal, wherein the latch unit comprises a first transistor and a second transistor, a base of the first transistor is connected to both the output terminal of the comparison unit and the collector of the second transistor, the collector of the first transistor is connected to a base of the second transistor, and an emitter of the second transistor is connected to a power Vcc terminal via a pull-up resistor.