Frequency converter providing employable output frequencies

Claim 2

In a frequency converter for providing an output having a frequency within a predetermined range of frequencies from an input of a frequency within or outside said predetermined range, the combination comprising means for rectifying an AC input to provide a rectified output of polarity alternating at a frequency within said predetermined range of frequencies, timing circuit means having a natural unsynchronized output frequency outside said predetermined frequency range, means coupled with said timing circuit means for overriding said natural frequency to provide an imposed output frequency from said timing circuit means within said predetermined range, and means coupled with said timing circuit means and said means for rectifying for controlling said means for rectifying to provide alternation of said rectified output at the output frequency of said timing circuit means within said predetermined range, said timing circuit means comprising an astable multivibrator having first and second output conditions naturally occurring at said natural unsynchronized frequency outside said predetermined frequency range, and said means for overriding said natural frequency comprising means for decreasing the duration of both said first and second output conditions of said multivibrator in response to the frequency of the AC input thereby providing repetitive alternate occurrence of said first and second output conditions at said imposed frequency within said predetermined frequency range.

Claim 3

The combination according to claim 1 wherein said means for decreasing the duration of said output conditions of said multivibrator comprises pulse production means for providing a pulse at each of the crossover points of an alternating input voltage, and means for supplying said pulses to said multivibrator to alter each output condition thereof at a time approaching the natural duration of each output condition.

Claim 4

The combination according to claim 2 wherein said multivibrator comprises first and second transistors, means coupling together said first and second transistors for halting conduction of eitHer of said first and second transistors in response to conduction of the remaining one of said first and second transistors, first and second output means connected with said first and second transistors for providing said first and second output conditions of said multivibrator, and time delay means coupled with each of said first and second transistors for establishing the natural unsynchronized duration of conduction and nonconduction of said transistors, said pulse production means being connected with each of said transistors for alternately driving each of said transistors into conduction prior to expiration of the natural duration of conduction of the remaining transistor.

Claim 5

The combination according to claim 1 wherein said means for rectifying comprises first and second signal responsive rectifier means for providing rectified output voltage of opposite polarities, respectively, said means for controlling said means for rectifying including means coupled with each of said first and second rectifier means for alternately applying trigger signals thereto corresponding to said first and second output conditions of said timing circuit means, whereby the polarity of rectified output voltage alternates at said imposed frequency of said timing circuit means within said predetermined frequency range.

Claim 6

In a frequency converter for providing an output having a frequency within a predetermined range of frequencies from an input of a frequency within or outside said predetermined range, the combination comprising means for rectifying an AC input to provide a rectified output of polarity alternating at a frequency within said predetermined range of frequencies, timing circuit means having a natural unsynchronized output frequency outside said predetermined frequency range, means coupled with said timing circuit means for overriding said natural frequency to provide an imposed output frequency from said timing circuit means within said predetermined range, and means coupled with said timing circuit means and said means for rectifying for controlling said means for rectifying to provide alternation of said rectified output at the output frequency of said timing circuit means within said predetermined range, said timing circuit means comprising an astable multivibrator, said means coupled with said timing circuit means and said means for rectifying for controlling said means for rectifying including means coupled with said multivibrator for providing alternating steering signals effecting alternation of said rectified output from said means for rectifying, said combination further including rectifying and smoothing means for providing a DC biasing potential for said multivibrator and said steering circuit means by rectification of the AC input and smoothing of the resultant DC signal, said means coupled with said timing circuit means for overriding said natural frequency including pulse production means coupled with said rectifying and smoothing means for receiving the rectified DC signal of said rectifying and smoothing means, prior to smoothing, and for applying pulses in synchronization the AC input to said multivibrator to change the frequency thereof from said natural frequency to said imposed frequency.

Claim 7

In a frequency converter for providing an output having a frequency within a predetermined range of frequencies from an input of a frequency within or outside said predetermined range, the combination comprising means for rectifying an AC input to provide a rectified output of polarity alternating at a frequency within said predetermined range of frequencies, timing circuit means having a natural unsynchronized output frequency outside said predetermined frequency range, means coupled with said timing circuit means for overriding said natural frequency to provide an imposed output frequency from said timing circuit means within said predetermined range, and means coupled with said timing circuit means and said means for rectifying for controlling said means for rectifying to provide alternation of said rectified output at the output frequency of said timing circuit means within said predetermined range, said timing circuit means comprising an astable multivibrator, said means coupled with said timing circuit means and said means for rectifying for controlling said means for rectifying including means coupled with said multivibrator for providing alternating steering signals effecting alternation of said rectified output from said means for rectifying, said combination further including rectifying and smoothing means for providing a DC biasing potential for said multivibrator and said steering circuit means by rectification of the AC input and smoothing of the resultant DC signal, said means coupled with said timing circuit means for overriding said natural frequency including pulse production means coupled with said rectifying and smoothing means for receiving the rectified DC signal of said rectifying and smoothing means, prior to smoothing, and for applying pulses in synchronization the AC input to said multivibrator to change the frequency thereof from said natural frequency to said imposed frequency.

Claim 8

The combination according to claim 5 wherein said means for rectifying to provide a rectified output of alternating polarity includes a plurality of unidirectional switching means, means for coupling the AC input with said unidirectional switching means, said means for providing alternating steering signals being coupled with said unidirectional switching means for triggering said switching means into conduction and said means for applying pulses to said multivibrator being coupled with said steering circuit means for inhibiting the triggering of said unidirectional switching means during production of said pulses.

Claim 9

A frequency converter for providing an output within a range of employable frequencies from an input of a frequency within or outside said range of employable frequencies including means for rectifying an AC input and for providing a rectified output of alternating polarity, means coupled with said means for rectifying for controlling the polarity of rectified output from said rectifying means, means coupled with said means for controlling the polarity for controlling the duration between output polarity alternations, means for producing pulses in synchronization with crossover points of the AC input, means for applying the pulses from the means for producing pulses to said means for controlling the duration to control the timing thereof, and means for applying the pulses from the means for producing pulses to said means for controlling the polarity for inhibiting operation of the means for controlling the polarity during the application of said pulses thereto, said means for rectifying including a first and second rectifier means for providing outputs of alternate polarities, said means for controlling the polarity including first and second steering circuit means for alternately directing trigger signals to said first and second rectifier means, respectively, said means for controlling the duration being coupled with said first and second steering circuit means for alternately actuating said first and second steering circuit means at a frequency determined by said means controlling the duration, and said means for applying the pulses to said means for controlling the polarity being coupled with both said first and second steering circuit means for inhibiting operation of both said first and second steering circuit

Claim 10

A frequency converter for providing an output within a range of employable frequencies from an input of a frequency within or outside said range of employable frequencies including means for rectifying an AC input and for providing a rectified output of alternating polarity, means coupled with said means for rectifying for controlling the polarity of rectified output from said rectifying means, means coupled with said means for controlling the polarity for controlling the duration between output polarity alternations, means for producing pulses in synchronization with crossover points of the AC input, means for applying the pulses from the means for producing pulses to said means for controlling the duration to control the timing thereof, and means for applying the pulses from the means for producing pulses to said means for controlling the polarity for inhibiting operation of the means for controlling the polarity during the application of said pulses thereto, said means for rectifying including a first and second rectifier means for providing outputs of alternate polarities, said means for controlling the polarity including first and second steering circuit means for alternately directing trigger signals to said first and second rectifier means, respectively, said means for controlling the duration being coupled with said first and second steering circuit means for alternately actuating said first and second steering circuit means at a frequency determined by said means controlling the duration, and said means for applying the pulses to said means for controlling the polarity being coupled with both said first and second steering circuit means for inhibiting operation of both said first and second steering circuit

Claim 11

The frequency converter according to claim 7 wherein said first and second rectifier means comprise first and second controlled rectifier bridges, respectively, each of said bridges comprising a plurality of controlled rectifiers, said controlled rectifiers each including a control electrode for readying the controlled rectifier for conduction upon energization of said electrode, said first and second steering means being coupled to ones of said control electrodes for controlling conduction of said controlled rectifiers, and said means for producing pulses including means for providing pulses of sufficient duration to allow extinguishing of a conducting controlled rectifier before triggering of a further controlled rectifier.

Claim 12

A frequency converter for providing an output within a range of employable frequencies from an input of a frequency within or outside said range of employable frequencies including means for rectifying an AC input and for providing a rectified output of alternating polarity, means coupled with said means for rectifying for controlling the polarity of rectified output from said rectifying means, means coupled with said means for controlling the polarity for controlling the duration between output polarity alternations, means for producing pulses in synchronization with crossover points of the AC input, means for applying the pulses from the means for producing pulses to said means for controlling the polarity for inhibiting operation of the means for controlling the polarity during the application of said pulses thereto, and means for deriving a DC operating potential for said triggering means and said timing means, said means for deriving including further means for rectifying the AC input and means for smoothing the rectified signal of said further means for rectifying, said means for producing pulses being coupled to said further means for rectifying

Claim 13

A frequency converter for providing an output within a range of employable frequencies from an input of a frequency within or outside said range of employable frequencies including means for rectifying an AC input and for providing a rectified output of alternating polarity, means coupled with said means for rectifying for controlling the polarity of rectified output from said rectifying means, means coupled with said means for controlling the polarity for controlling the duration between output polarity alternations, means for producing pulses in synchronization with crossover points of the AC input, means for applying the pulses from the means for producing pulses to said means for controlling the polarity for inhibiting operation of the means for controlling the polarity during the application of said pulses thereto, and means for deriving a DC operating potential for said triggering means and said timing means, said means for deriving including further means for rectifying the AC input and means for smoothing the rectified signal of said further means for rectifying, said means for producing pulses being coupled to said further means for rectifying

Claim 14

The frequency converter according to claim 9 wherein said means for producing pulses comprises means for producing a pulse in response to reduction in voltage to a predetermined level between maximum rectified unidirectional pulse levels from said further means for rectifying, and for terminating a pulse in response to an increase in voltage following said reduction, whereby the produced pulses correspond to a time period spanning the crossover points of the AC input voltage.

Claim 15

A frequency converter for providing an output within a range of employable frequencies from an input of a frequency within or outside said range of employable frequencies including means for rectifying an AC input and for providing a rectified output of alternating polarity, means coupled with said means for rectifying for controlling the polarity of rectified output from said rectifying means, means coupled with said means for controlling the polarity for controlling the duration between output polarity alternations, means for producing pulses in synchronization with crossover points of the AC input, means for applying the pulses from the means for producing pulses to said means for controlling the duration to control the timing thereof, and means for applying the pulses from the means for producing pulses to said means for controlling the polarity for inhibiting operation of the means for controlling the polarity during the application of said pulses thereto, said means for controlling the duration comprises means for providing first and second output conditions at a natural unsynchronized frequency lower than the desired output frequency of said frequency converter, said means for providing first and second output conditions being responsive to pulses applied thereto near the end of the natural duration of either of said output conditions for altering the output condition thereof.

Claim 16

A frequency converter for providing an output within a range of employable frequencies from an input of a frequency within or outside said range of employable frequencies including means for rectifying an AC input and for providing a rectified output of alternating polarity, means coupled with said means for rectifying for controlling the polarity of rectified output from said rectifying means, means coupled with said means for controlling the polarity for controlling the duration between output polarity alternations, means for producing pulses in synchronization with crossover points of the AC input, means for applying the pulses from the means for producing pulses to said means for controlling the duration to control the timing thereof, and means for applying the pulses from the means for producing pulses to said means for controlling the polarity for inhibiting operation of the means for controlling the polarity during the application of said pulses thereto, said means for controlling the duration comprises means for providing first and second output conditions at a natural unsynchronized frequency lower than the desired output frequency of said frequency converter, said means for providing first and second output conditions being responsive to pulses applied thereto near the end of the natural duration of either of said output conditions for altering the output condition thereof.