DC/AC inverter substrate having voltage abnormality detector circuit
View Patent ↗A DC/AC inverter substrate includes a voltage abnormality detector circuit. All of a high voltage side detection sensor, a low voltage side detection sensor, and a high-voltage and low-voltage detection sensor in the voltage abnormality detector circuit are disposed without being electrically connected to a secondary side of a transformer or to a connection point. Those detection sensors are not damaged since overvoltage is not applied to the voltage abnormality detector circuit when abnormal discharge occurs because the detection sensors are not electrically connected.
1. A DC/AC inverter substrate having a voltage abnormality detector circuit, the voltage abnormality detector circuit comprising:
a transformer;
a connection point for connecting to a lamp;
a low voltage side detection sensor that is disposed at the connection point without being electrically connected to the connection point;
a low-voltage voltage abnormality detector circuit that receives a sense voltage from the low voltage side detection sensor and outputs an abnormality detection signal when the sense voltage is equal to or higher than a set value; and
a control circuit that receives the abnormality detection signal from the low-voltage voltage abnormality detector circuit and stops transformer output,
wherein the low voltage side detection sensor is disposed in a vicinity of a terminal of the lamp return current side of the connection point without being electrically connected to the connection point, and
wherein the closest distance between the low voltage side detection sensor and the connection point is 1 to 10 mm.
2. A DC/AC inverter substrate having a voltage abnormality detector circuit according to claim 1 , wherein a width of the low voltage side detection sensor is equal to or larger than 3 mm.
3. A DC/AC inverter substrate having a voltage abnormality detector circuit according to claim 1 , wherein the low voltage side detection sensor is disposed on an opposite surface of a substrate surface on which the transformer and the connection point are mounted.
4. A light source unit comprising the DC/AC inverter substrate having a voltage abnormality detector circuit according to claim 1 , wherein the lamp is connected to the connection points.
5. A liquid crystal display device, comprising:
a liquid crystal panel;
an electric circuit that drives the liquid crystal panel; and
the light source unit according to claim 4 .