Power unit and lighting apparatus
AssigneeSharp Kabushiki Kaisha
InventorNoriaki Terazawa
Life of this patent
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Abstract
When a voltage V detected by a voltage detecting section is lower than a first threshold value Vth1, an NPN transistor is turned on, a control terminal Ve is placed at a low level, and an overload protection circuit section halts the operation of a switching circuit section. When the voltage V detected by the voltage detecting section becomes higher than the first threshold value Vth1, the NPN transistor is turned off, the control terminal Ve is placed at a high level, and the overload protection circuit section resets the halt of the operation of the switching circuit section and makes the operation resumed.
Claims6
A power unit comprising:
- a conversion device for converting an AC into a DC,
- a switching element for switching the DC supplied from the conversion device to a primary side of a transformer,
- an overload detection device for detecting an overload state of a load provided on a secondary side of the transformer, and
- an overload protection device for halting an operation of the switching element and keeping the halt when the overload detection device detects the overload state, comprising:
- a voltage detecting device for detecting a voltage output by the conversion device;
- and
- a control device for controlling the switching element to halt the operation thereof when the voltage detected by the voltage detecting device is lower than a first threshold value,
- the first threshold value being larger than an output voltage value of the conversion device at which the overload detection device detects the overload state.
Dependencies are inferred from the claim text.