Abstract: A power adapter having a replaceable plug has a body having a recess formed in the body and an engagement mechanism inside the recess. A plug, slidably mounted inside the recess, has a bottom board having an engagement mechanism thereon and is slid so that the engagement mechanism of the plug engages or disengages the engagement mechanism inside the recess. A fixing cover is mounted inside the recess and is slidably moved to a first location and a second location. When located at the first location, the fixing cover is located inside the recess, the bottom board abuts the plug fixed inside the recess, and the plug is retrained restrained from moving. When located at the second location, the fixing cover is partially moved away from the recess and maintains a distance to the bottom board, and the plug can be removed from the recess.

Abstract: A power adapter having a replaceable plug has a body having a recess formed in the body and an engagement mechanism inside the recess; a plug slidably mounted inside the recess, having a bottom board having an engagement mechanism thereon, and slid so that the engagement mechanism of the plug engages or disengages the engagement mechanism inside the recess; a fixing cover mounted inside the recess and slidably moved to a first location and a second location. When located at the first location, the fixing cover is located inside the recess, the bottom board abuts the plug fixed inside the recess, and the plug is retrained from moving; when located at the second location, the fixing cover is partially moved away from the recess and maintains a distance to the bottom board, and the plug can be removed from the recess.

Abstract: Provided is a light adjusting noise reduction circuit in which the vibration noise accompanying turning ON/OFF of a piezoelectric transformer. A full bridge circuit is controlled by a full bridge drive circuit so as to switch an input voltage (VB1) from an input voltage source and outputs it to a low pass filter. The output from the low pass filter is supplied to a piezoelectric transformer. The output current (IO) from the piezoelectric transformer is supplied to a discharge tube. Each of FET of the full bridge circuit has a drive frequency decided by a voltage control type oscillator. The full bridge circuit is connected to a duty variable circuit and a peak value control circuit. The peak value control circuit forms a rise and a fall of a waveform to be (1?cos?t).

Abstract: A dimmer noise reducing circuit wherein vibration noise accompanying the activation/deactivation of a piezoelectric transformer can be reduced, while non-uniformity of brightness of a discharge lamp can be prevented. A chopping circuit turns on/off an output from an input voltage source in a given periodic manner and a full-bridge circuit that receives an output voltage (vb1) of the chopping circuit. An output from a lowpass filter is supplied to a piezoelectric transformer, an output current of which (Io) is supplied to a discharge lamp. The full-bridge circuit is controlled by a full-bridge drive circuit to switch the input voltage (VB1) from the chopping circuit. The drive frequencies of the FETs of the full-bridge circuit are decided by a voltage-controlled oscillator. The chopping circuit is connected to a duty varying circuit the full-bridge circuit is caused to operate with its duty fixed.