Variable input voltage regulator circuit

• US 4,590,546 A
• Filed: 02/23/1984
• Issued: 05/20/1986
• Est. Priority Date: 02/23/1984
• Status: Expired due to Term

• Current Assignee: RCA Corporation
• Original Assignee: RCA Corporation
• Inventors: Maile, Donald W.
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): Rebsch, D. L.
• Application Number:
  US06/582,685
• Time in Patent Office: 817 Days
• Field of Search: 307/64, 307/80, 323/299, 323/300, 363/143, 363/37, 363/142
• US Class Current: 363/37
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc
• CPC Class Codes: H02M 3/33569 having several active switching elements H02M3/3353 takes precedence

Abstract

A power supply provides a regulated DC voltage level for a wide range of AC supply levels. The power supply incorporates circuitry which forms a voltage doubler or a full wave rectifier in response to the level of the AC supply voltage. The transition between the type of rectification is rapid, so that the regulated voltage remains constant.

Claims

1. A power supply comprising:

a source of unregulated AC voltage having an amplitude between a first and a second level;

means for providing a voltage level representative of the amplitude of said unregulated AC voltage;

means responsive to said representative voltage level for producing an output signal when said representative voltage level is above a predetermined level corresponding to an unregulated AC voltage amplitude intermediate said first and second levels;

first rectifying means coupled to said unregulated AC voltage source for producing a first DC voltage from said AC voltage;

circuit means for forming a second rectifying means for producing a second DC voltage from said AC voltage when said circuit means is coupled to said first rectifying means;

switch means responsive to said output signal for coupling said circuit means to said first rectifying means when said unregulated AC voltage level is above said intermediate level comprising;

a bidirectional switch coupled to said first rectifying means and to said circuit means;

a first transistor coupled to said output signal producing means; and

a second transistor, regeneratively coupled to said first transistor and to said bidirectional switch, said first and second transistors cooperating to provide rapid switching of said bidirectional switch; and

regulator means responsive to said first or second DC voltage for providing a DC output voltage having a fixed regulated level with respect to variations in the level of said unregulated AC voltage between said first and second levels.

2. The arrangement defined in claim 1, wherein said first rectifying means comprises a half-wave bridge rectifier.

3. The arrangement defined in claim 2, wherein said circuit means comprises a switchable current path for modifying said half-wave bridge rectifier to form a full-wave bridge rectifier.

4. The arrangement defined in claim 1, wherein said switch means comprises a triac.

5. The arrangement defined in claim 1, wherein said output signal producing means incorporates means for producing hysteresis for determining the level of said representative voltage level at which said output signal producing means produces said output signal when said representative voltage level varies above and below said predetermined level.