US 2007/0182345 A1 · Monitor and power circuit thereof

Abstract

A monitor and a power circuit thereof. The monitor includes a power circuit and a lamp. The power circuit driving the lamp to emit light includes an AC-to-DC converter, a transformer, a switch, a pulse width modulation (PWM) unit, a DC filter and a Royer circuit. The AC-to-DC converter receives a first AC voltage and generates a first DC voltage. The transformer has a secondary side coil for generating a second AC voltage, and a primary side coil, which has one end for receiving the first DC voltage and the other end coupled to a low potential through the switch. The PWM unit controls the switch to turn on to adjust the second AC voltage. The DC filter filters the second AC voltage into a second DC voltage. The Royer circuit generates a third AC voltage for driving the lamp to emit the light according to the second DC voltage.

Claims4

Dependent claims

A monitor, comprising:

an AC-to-DC converter for receiving a first AC voltage and thus generating a first DC voltage;
a transformer having a primary side coil and a secondary side coil for generating a second AC voltage;
a switch, wherein one end of the primary side coil receives the first DC voltage, and the other end of the primary side coil is coupled to a low potential through the switch;
a PWM (Pulse Width Modulation) unit for controlling the switch to turn on to adjust the second AC voltage;
a DC filter for filtering the second AC voltage into a second DC voltage;
a Royer circuit for generating a third AC voltage according to the second DC voltage;
a lamp, wherein the third AC voltage drives the lamp to emit light;
and
a feedback circuit for receiving a first feedback signal provided when the lamp is emitting the light and thus generating a second feedback signal, wherein the PWM unit controls the switch according to the second feedback signal.

6 more elements

Dependencies are inferred from the claim text.

Monitor and power circuit thereof

Life of this patent

Monitor and power circuit thereof

Life of this patent

Abstract

Claims4