Fixed phase power controller with analog trigger

• US 7,224,151 B2
• Filed: 02/04/2005
• Issued: 05/29/2007
• Est. Priority Date: 02/04/2005
• Status: Expired due to Fees

• Current Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Original Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Inventors: Ballenger, Matthew B., Weyhrauch, Ernest C.
• Primary Examiner(s): Chen; Shih-Chao
• Assistant Examiner(s): A, MINH D
• Application Number:
  US11/051,943
• Publication Number:
  US 20050122086A1
• Time in Patent Office: 844 Days
• Field of Search: 315/203, 315/205, 315/208, 315/207, 323/237, 323/242, 323/300, 323/320, 323/325, 323/327, 323/365, 323/902
• US Class Current: 323/237
• CPC Class Codes: H05B 39/044 continuously H05B39/042 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A fixed phase power controller that converts a line voltage to an RMS load voltage includes an analog control block with a capacitor that receives an input that is independent of a change in magnitude of the line voltage and that charges and discharges to provide a trigger signal at a first frequency, a reset circuit that periodically resets an initial condition of the analog control block, a synchronization connection that provides a sync signal that synchronizes the trigger signal with a waveform of the line voltage, and a control circuit that clips a load voltage based on the synchronized trigger signal to define the RMS load voltage. The controller finds application in a lamp where it reduces the line voltage to an RMS load voltage suitable for a light emitting element.

Claims

1. A fixed phase power controller that converts a line voltage to an RMS load voltage, the controller comprising:

line terminals for a line voltage and load terminals for a load voltage;

a full wave bridge connected to said line and load terminals;

a transistor switch connected to said bridge and that clips the load voltage;

a DC source that is independent of a change in magnitude of the line voltage;

a capacitor that has one terminal connected to said DC source and to said transistor switch to turn said transistor switch off and on at a first frequency that defines the RMS load voltage; and

a reset circuit connected in parallel with said capacitor for resetting said capacitor to an initial state at a rate that corresponds to the first frequency.

2. The controller of claim 1, wherein said transistor switch comprises at least one of an SCR, triac and diac.

3. The controller of claim 2, wherein said transistor switch comprises a diac and an SCR is triggered by said diac.

4. The controller of claim 2, wherein said transistor switch comprises a diac and a triac that is triggered by said diac.