High voltage converter

• US 5,103,387 A
• Filed: 01/31/1991
• Issued: 04/07/1992
• Est. Priority Date: 01/31/1991
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: McGinn, Donald S., Sutherland, Brian A. F. S., Rosenbaum, Stanley D.
• Primary Examiner(s): Wong, Peter S.
• Application Number:
  US07/648,776
• Time in Patent Office: 432 Days
• Field of Search: 363/16, 363/17, 363/20, 363/21, 363/89, 363/97, 363/127, 323/271, 323/272, 307/46, 307/66, 307/86, 307/72
• US Class Current: 363/21.13
• CPC Class Codes: H02M 3/33569 having several active switching elements H02M3/3353 takes precedence
• CPC Class Codes: H04M 19/02 providing ringing current or supervisory tones, e.g. dialling tone or busy tone

Abstract

High voltage converters are disclosed. The converters include at least a pair of transistor switches provided on the secondary windings of a flyback transformer. The transistor switches are controlled to be conducting, variably conducting and non-conducting so that the power flow between the transformer and a load can be controlled. Various configurations of a connection switch network are also disclosed.

Claims

1. A high voltage converter for providing a power to a load from a DC voltage source, by load connection lines comprising:

line driver circuit means to be connected to said DC voltage source for providing a line drive outoput;

high voltage circuit means to be connected to said DC voltage source for providing a high voltage output; and

connection switch means for selectively connecting said line driver circuit means and said high voltage circuit means to said load connection lines for providing said line drive output, said high voltage output or a combination thereof,

said high voltage circuit means in turn comprising;

a flyback transformer having a primary winding and two secondary windings;

a primary transistor switch connected to said primary winding for supplying the pulsed power thereto from said DC voltage source in a controlled pulsing manner;

a secondary transistor switch and diode combination connected to each of said two secondary windings for controlling the flow of the power generated therein as the result of the power supplied to said primary winding; and

power control circuit means for providing transistor control signals to said transistor switches and switch control signals to said connection switch means in that one of said transistor control signals is a high frequency pulsing signal and is applied to said primary transistor switch to turn the same to conducting so that said pulsed power is supplied to said primary winding in the controlled pulsing manner, the others of said transistor control signals are applied to said secondary transistor switches in order to turn on one of the two secondary transistors at one time in a controlled manner so as to control the flow of power between said high voltage circuit means and said load connection lines.

2. The high voltage converter, according to claim 1, wherein:

the conduction of said conducting secondary transistor switches is variable.

3. The high voltage converter according to claim 2, wherein:

said line drive circuit means is connected to said connection switch means which in turn is connected to the load connection line;

said power control circuit means further provides switch control signals; and

said connection switch means comprise a plurality of on/off switches operative in response to said switch control signals.

4. The high voltage converter, according to claim 3, wherein said primary transistor switch and said primary winding are connected in series to said DC voltage source, and said secondary transistor switches and diodes and said secondary windings are connected in a loop.

5. The high voltage converter to claim 4, wherein a capacitor is provided between a point connecting said two secondary windings and one of the two polarities of said DC voltage source, said point being further connected said connection switch means for providing said high voltage output thereto.

6. The high voltage converter, according to claim 5, wherein said high voltage circuit means further comprises an overcurrent detection means for detecting an overcurrent which may flow out of said DC voltage source.

7. The high voltage converter, according to claim 6, further comprising a programmable load and command means connected to said power control circuit means for providing programmed reference signals and said power control circuit means further comprise error detecting means for generating error signals in response to said high voltage output with respect to said programmed reference signals.

8. The high voltage converter, according to claim 3, wherein said connection switch means comprise at least two sets of metallic relay switches and a solid-state switch, all operative in response to said switch control signals.

9. The high voltage converter, according to claim 8, wherein said two sets of metallic relay switches are arranged in an offset manner.

10. The high voltage converter, according to claim 9, further comprising a programmable load and command means connected to said power control circuit means for providing programmed reference signals and said power control circuit means further comprise error detecting means for generating error signals in response to said high voltage output with respect to said programmed reference signals.

11. The high voltage converter, according to claim 2, further comprising a programmable load and command means connected to said power control circuit means for providing programmed reference signals and said power control circuit means further comprise error detecting means for generating error signals in response to said high voltage output with respect to said programmed reference signals.