Oscillator amplitude regulating system

• US 3,973,220 A
• Filed: 06/02/1975
• Issued: 08/03/1976
• Est. Priority Date: 06/02/1975
• Status: Expired due to Term

• Current Assignee: Varo, Inc. (Northrop Grumman Corporation)
• Original Assignee: NI-Tech, Inc.
• Inventors: Fender, Ferdinand G., Karlsson, Tore S.
• Primary Examiner(s): Grimm, Siegfried H.
• Application Number:
  US05/582,913
• Time in Patent Office: 428 Days
• Field of Search: 331/109, 331/117 R, 331/182, 331/183
• US Class Current: 331/109
• CPC Class Codes: H02M 3/3385 with automatic control of output voltage or current H02M3/33561 takes precedence
• CPC Class Codes: H03L 5/00 Automatic control of voltage, current, or power

Abstract

The disclosure relates to an amplitude control for controlling the peak amplitude of a transistor oscillator output alternating voltage and to an improved regulating system which includes an oscillator associated with the amplitude control for converting a DC voltage to an alternating output voltage having a regulated or controlled peak amplitude. The amplitude control comprises a control voltage generating means for providing a control voltage and clipping means coupled between the base of the oscillator transistor and the control voltage generator for varying the bias of the oscillator transistor responsive to the control voltage to thereby control the peak amplitude of the oscillator alternating output voltage.

Claims

1. A regulating system for converting a DC voltage to an alternating voltage of constant peak amplitude comprising:

an oscillator including a transistor having a base and coupled to the DC voltage for converting the DC voltage to an alternating output voltage;

control voltage means responsive to the peak amplitude of the alternating output voltage for providing a control voltage having a magnitude which is inversely related to the peak amplitude of the alternating output voltage, said control voltage means comprising a transformer winding inductively coupled to said oscillator for sensing the alternating voltage output and for providing an alternating first intermediate control voltage which is directly proportional in magnitude to the output alternating voltage from which said control voltage is derived; and

clipping means coupled between said base and said control voltage means for controlling the bias of said transistor to thereby cause said oscillator alternating output voltage to vary in direct relation to said control voltage;

whereby,

when the peak amplitude of the output voltage increases, said control voltage decreases causing said clipping means to bias said transistor for decreased output voltage and when the peak amplitude of the output voltage decreases, said control voltage increases causing said clipping means to bias said transistor for increased output voltage to thereby render the peak amplitude of said oscillator alternating output voltage constant.

2. A regulating system in accordance with claim 1 wherein said control voltage means further comprises a rectifier coupled to said transformer winding for rectifying said alternating first intermediate control voltage and a comparator for comparing said rectified first intermediate control voltage to a reference voltage for producing a second intermediate control voltage which is directly related to the peak amplitude of the alternating output voltage.

3. A regulating system in accordance with claim 2 wherein said comparator comprises a pair of transistors coupled together in a differential pair configuration and a zener diode coupled to a given one of said differential pair transistors for providing said reference voltage and wherein said given one of said differential pair transistors provides said second intermediate control voltage.

4. A regulating system in accordance with claim 3 wherein said control voltage means further comprises an inverting transistor coupled to said given one of said differential pair of transistors for inverting said second intermediate control voltage to thereby provide said control voltage.

5. A regulating system for converting a DC voltage to an alternating voltage of constant peak amplitude notwithstanding changing load conditions comprising:

an oscillator including an NPN transistor having a base, a collector and an emitter, said collector being coupled to the DC voltage for converting the DC voltage to an alternating output voltage at said emitter;

control voltage means including a sensing transformer winding inductively coupled to said emitter for deriving a first intermediate control voltage which is directly related to the peak amplitude of said alternating output voltage, a rectifier coupled to said sensing winding for rectifying said first intermediate control voltage, a comparator coupled to said rectifier and including a zener diode for comparing said rectified first intermediate control voltage to a reference voltage for providing a second intermediate control voltage directly related to the peak amplitude of said alternating output voltage, and an inverting transistor coupled to said comparator for providing a control voltage inversely related to the peak amplitude of said alternating output voltage; and

clipping means comprising a diode having an anode and a cathode, said anode being coupled to said oscillator transistor base and said cathode being coupled to said inverting transistor to thereby control the bias of said oscillator transistor responsive to said control voltage to cause the oscillator peak amplitude to vary in direct relation to said control voltage;

whereby,

with said control voltage varying in inverse relation to the output voltage, and with the clipping means controlling the oscillator transistor bias in direct relation to said control voltage, the peak amplitude of the oscillator output voltage is maintained constant notwithstanding changing loading conditions upon said oscillator.