Circuit for generating first and second in-phase alternating signals

• US 5,260,669 A
• Filed: 01/30/1992
• Issued: 11/09/1993
• Est. Priority Date: 09/12/1990
• Status: Expired due to Fees

• Current Assignee: Lectro Products, Inc. (Eaton Corporation PLC.)
• Original Assignee: Lectro Products, Inc. (Eaton Corporation PLC.)
• Inventors: Beaty, Henry L., Higgins, Alton N.
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): TRAN, SINH N
• Application Number:
  US07/828,139
• Time in Patent Office: 649 Days
• Field of Search: 328/133, 328/134, 328/155
• US Class Current: 327/3
• CPC Class Codes: G08G 1/097 Supervising of traffic control systems, e.g. by giving an alarm if two crossing streets have green light simultaneously

Abstract

A device for providing an orderly shut-down of a system of interconnected traffic lights upon loss of its primary electrical power is disclosed. A device for permitting consistent reapplication of power to a line conditioner having a ferroresonant transformer is also disclosed. Further, a battery charger for charging a battery system including a plurality of battery cells coupled in series is disclosed. Additionally, a device for determining proper operation of a power transistor by monitoring its saturation voltage and emitter current is also disclosed. Finally, a device for generating a first alternating signal in-phase with a separately generated second alternating signal is disclosed.

Claims

1. In a device for generating a first alternating signal having a desired frequency, a circuit for adjusting a phase angle of said first alternating signal to equal a phase angle of a second alternating signal, the device comprising:

means for generating said first alternating signal, said generating means having an input, said frequency of said first alternating signal being dependent upon a characteristic of a control signal applied to said input;

means for providing first, second and third control signals, said first control signal having a characteristic to cause said first generating means to generate said first alternating signal at said desired frequency, said second control signal having a characteristic to cause said first generating means to generate said first alternating signal at a frequency above said desired frequency, and said third control signal having a characteristic to cause said first generating means to generate said first alternating signal at a frequency below said desired frequency;

means for comparing said phase angle of said first alternating signal to said phase angle of said second alternating signal; and

means responsive to said comparing means for selectively coupling one of said first, second or third control signals to said input to adjust said phase angle of said first alternating signal to equal said phase angle of said second alternating signal.

2. The device of claim 1 wherein said first signal generating means comprises a counter.

3. In a device for generating a first alternating signal having a desired frequency, a circuit for adjusting a phase angle of said first alternating signal to equal a phase angle of a second alternating signal, the device comprising:

a counter for generating said first alternating signal, said counter having an input, said desired frequency of said first alternating signal being dependent upon a frequency of a control signal applied to said input;

means for providing first, second and third control signals, said first control signal having a frequency to cause said first generating means to generate said first alternating signal at said desired frequency, said second control signal having a frequency to cause said first generating means to generate said first alternating signal at a frequency above said desired frequency, and said third control signal having a frequency to cause said first generating means to generate said first alternating signal at a frequency below said desired frequency;

means for comparing said phase angle of said first alternating signal to said phase angle of said second alternating signal; and

means responsive to said comparing means for selectively coupling said first control signal to said input if said phase angle of said first alternating signal equal said phase angle of said second alternating signal, coupling said second control signal to said input if the phase angle of said first alternating signal lags said phase angle of said second alternating signal, and coupling said third control signal to said input if the phase angle of said first alternating signal leads said phase angle of said second alternating signal.

4. A device for generating a first alternating signal in phase with a second alternating signal, each of said first and second alternating signals having a phase angle, said device comprising:

an input, said phase angle of said first alternating signal being responsive to a signal coupled to said input;

means for generating a primary alternating signal, an upper alternating signal and a lower alternating signal, said primary alternating signal having a frequency, said upper alternating signal having a frequency greater than said frequency of said primary alternating signal and said lower alternating signal having a frequency less than said frequency of said primary alternating signal;

means for comparing said phase angle of said first alternating signal with said phase angle of said second alternating signal;

means for selectively coupling one of said primary, upper or lower alternating signals to said input, said selectively coupling means coupling said primary alternating signal to the input when said phase angle of said first alternating signal equals said phase angle of said second alternating signal, coupling said upper alternating signal when said phase angle of said first alternating signal lags said phase angle of said second alternating signal and coupling said lower alternating signal when said phase angle of said first alternating signal leads said phase angle of said second alternating signal; and

means responsive to said coupling means for adjusting said phase angle of said first alternating signal.