POWER SUPPLY SYSTEM

• US 3,818,366 A
• Filed: 07/14/1972
• Issued: 06/18/1974
• Est. Priority Date: 10/07/1969
• Status: Expired due to Term

• Current Assignee: Hiroshi Goto, Hiroshi Matsushima, Ichiro Arimura, Yoshikazu Nakao
• Original Assignee: Hiroshi Goto, Hiroshi Matsushima, Ichiro Arimura, Yoshikazu Nakao
• Inventors: Arimura, Ichiro, Goto, Hiroshi, Matsushima, Hiroshi, Nakao, Yoshikazu
• Primary Examiner(s): Kaufman, Nathan
• Application Number:
  US05/272,033
• Time in Patent Office: 704 Days
• Field of Search: 307/200 330/27P
• US Class Current: 330/207.00P
• CPC Class Codes: G05F 1/573 with overcurrent detector
• CPC Class Codes: H02H 3/087 for dc applications
• CPC Class Codes: H03F 1/52 Circuit arrangements for protecting such amplifiers monitoring arrangements G01R31/28; increasing reliability in communication systems, e.g. using redundancy H04B1/74
• CPC Class Codes: H03F 3/3091 comprising two complementary transistors for phase-splitting

Abstract

A power supply system for an amplifier which is driven by two power supply means of opposite polarity and whose output swings substantially about zero potential level. The power supply system is provided with means for cutting off the active power supply means earlier than the passive power supply means in the event of the application of an excessively large input or overcurrent to the amplifier, thereby preventing any damage to the amplifier, power supply means and load.

Claims

1. A power supply system for a complementary single-end pushpull amplifier, said complementary single-end push-pull amplifier comprising an input signal receiving terminal, first and second amplification circuits which are connected in push-pull with respect to an output terminal for amplifying a signal applied to said input signal receiving terminal and producing an output at the output terminal, said output terminal being connected to a load, saId push-pull amplifier further having first, second and common terminals, said power supply system comprising first and second power sources each having an output terminal and a common terminal coupled to the common terminal of said amplifier, the output terminal of said first power source having a polarity opposite to that of the output terminal of said second power source with respect to said common terminals, first means for connecting the output terminal of said first power source to the first terminal of said amplifier, said first means including means for interrupting an overcurrent therethrough when said overcurrent exceeds a predetermined value, and second means for connecting the output terminal of said second power source to the second terminal of said amplifier, said second means including means for maintaining the current therethrough at least until said first means has interrupted said overcurrent exceeding said predetermined value, said amplifier producing a DC output when said second power source only is disconnected from said amplifier and producing no DC output when said first power source only is disconnected from said amplifier.

2. A power supply system according to claim 1, wherein said second means connects said second power source permanently with said amplifier.

3. A power supply system according to claim 2, wherein said first means connects said first power source with said amplifier through a fuse wire which melts when subjected to said overcurrent.

4. A power supply system according to claim 2, wherein said first power source comprises a circuit having a control element adapted to conduct a controlled current from said first power source to said amplifier, and said first means comprises overcurrent detecting means for detecting said overcurrent and means for causing said control element to become non-conductive when said overcurrent detecting means detects said overcurrent.

5. A power supply system according to claim 1, wherein said second means comprises means for interrupting the current therethrough when said current exceeds a second predetermined value larger than said first-mentioned predetermined value.

6. A power supply system according to claim 1, wherein said first means connects said first power source to said amplifier through a fuse wire which melts with said overcurrent, and said second means connects said second power source to said amplifier through a fuse wire which melts only with a current higher than said overcurrent.

7. A power supply system according to claim 1, wherein each of said first and second power sources comprises a circuit having a control element adapted to conduct a controlled current from the respective power source to said amplifier, and said first means comprises overcurrent detecting means for detecting said overcurrent and means for causing said control element thereof to become non-conductive when said detecting means detect said overcurrent flowing therethrough, and said second means comprises overcurrent detecting means for detecting a current larger than said overcurrent and means for causing said control element to become non-conductive when said overcurrent detecting means detects said current.

8. A power supply system according to claim 1, comprising a plurality of said amplifiers each connected to said first and second power sources, and a plurality of said first means each being connected between said active power source and the respective amplifier and being responsive to said overcurrent flowing therethrough to cut off said overcurrent, said second means being connected between said second power source and said plurality of said amplifiers for cutting off said overcurrent when the overcurrent flowing therethrough exceeds another predetermined value depending on the number of said amplifiers.

9. A power supply system according to claim 1, wherein said second means comprises means for interrupting the current therethrough responsive to the interruptIng operation of said first means.

10. A power supply system according to claim 9, wherein each of said first and second power sources comprises a circuit having a control element for conducting a controlled current from its own power source to said amplifier;

said first means comprises overcurrent detecting means for detecting said overcurrent, and means for causing said control element of said one power source to become non-conductive when said overcurrent detecting means detect said over-current; and

said second means comprises means for causing said control element of said other power source to become non-conductive when said control element of said one power source has been rendered non-conductive.