Regulated, controlled-rectifier power supply

Claim 2

A power supply of the class comprising, in combination, a source of alternating current energy, a load circuit, controlledrectifier switching means having a control input and interconnecting said source and said load circuit, said switching means being effective to couple said source to said load circuit during predetermined portions only of successive half-cycles of said alternating current energy, and a pulse signal source connected to said control input for providing pulse signals to said control input for initiating conduction of said switching means, wherein the improvement comprises, in combination, means included in said pulse signal source for generating a continuing periodic waveform increasing with time to a fixed magnitude and synchronized with said alternating current energy, means providing a control voltage which varies with the magnitude of the energy delivered to said load circuit, a threshold deVice having an input and an output for producing only one of said pulse signals during each successive half cycles of said alternating current whenever the signal applied to its input exceeds a predetermined magnitude, summing mode for additively applying said periodic waveform and said control voltage to the input of said threshold device, whereby variations in the amplitude of said control voltage varies the time position of said pulse signals relative to said alternating current, and means for generating an inhibiting signal whenever the magnitude of energy delivered to said load circuit exceeds a predetermined value, and means responsive to said inhibiting signal for providing a signal to said summing mode which prevents a signal presented to the input of said threshold device from exceeding said predetermined magnitude needed to produce one of said pulse signals.

Claim 3

A power supply as set forth in claim 1 wherein said means for generating said periodic waveform comprises, in combination, a timing capacitor, means for charging said capacitor at a rate substantially independent of variations in the amount of energy being delivered to said load, and means responsive to the zero-crossings of the waveform of said alternating current energy for repeatedly discharging said capacitor, thereby forming said periodic waveform.

Claim 4

A power supply as set forth in claim 2 including diode clamping means for fixing the peak-to-peak amplitude of said periodic waveform.

Claim 5

A power supply of the class comprising, in combination, a source of alternating current energy, a rectifier for converting said alternating current energy into pulsating direct current energy, a controlled-rectifier having a control electrode and a switched circuit path, said switched circuit path being serially connected with an inductor and a filter capacitor across the output of said rectifier, a catching diode connected in parallel with said inductor and said filter capacitor and poled to permit continued current flow through said inductor when said controlled-rectifier ceases conduction, and a load circuit connected in parallel with said filter capacitor, wherein the improvement comprises, in combination, a timing capacitor, means for charging said timing capacitor at substantially constant rate, means coupled to said source and responsive to the zero-crossings of the waveform of said alternating current for periodically discharging said timing capacitor to produce a period timing waveform of fixed amplitude and waveshape which is synchronized with said alternating current energy, a source of a control signal, a threshold circuit for producing a firing signal when said timing waveform reaches a predetermined threshold level, said circuit including means for shifting said threshold level relative to said timing waveform in response to variations in the amplitude of said control signal, and means for applying said firing signal to the control electrode of said controlled-rectifier to initiate conduction therethrough, said load circuit comprising, a transistor bridge circuit having a switching signal input, a direct current power input and an alternating current power output, said direct current power input being connected to said filter capacitor and said alternating current power output being connected to utilization load circuit, a switching signal generator connected to the switching signal input of said bridge, a first source for operating potential connected to said generator, and a second source connected to the alternating current power output of said bridge for providing auxiliary operating power to said switching signal generator when the supply of operating potential from first source is terminated.

Claim 6

A power supply of the class comprising, in combination, a source of alternating current energy, a rectifier for converting said alternating current energy into pulsating direct current energy, a controlled-rectifier having a control electrode and a switched circuit path, said switched circuit path being serially connected with an inductor and a filter capacitor across the output of said rectifier, a catching diode connected in parallel with said inductor and said filter capacitor and poled to permit continued current flow through said inductor when said controlled-rectifier ceases conduction, and a load circuit connected in parallel with said filter capacitor, wherein the improvement comprises, in combination, a timing capacitor, means for charging said timing capacitor at substantially constant rate, means coupled to said source and responsive to the zero-crossings of the waveform of said alternating current for periodically discharging said timing capacitor to produce a period timing waveform of fixed amplitude and waveshape which is synchronized with said alternating current energy, a source of a control signal, a threshold circuit for producing a firing signal when said timing waveform reaches a predetermined threshold level, said circuit including means for shifting said threshold level relative to said timing waveform in response to variations in the amplitude of said control signal, and means for applying said firing signal to the control electrode of said controlled-rectifier to initiate conduction therethrough, said load circuit comprising, a transistor bridge circuit having a switching signal input, a direct current power input and an alternating current power output, said direct current power input being connected to said filter capacitor and said alternating current power output being connected to utilization load circuit, a switching signal generator connected to the switching signal input of said bridge, a first source for operating potential connected to said generator, and a second source connected to the alternating current power output of said bridge for providing auxiliary operating power to said switching signal generator when the supply of operating potential from first source is terminated.

Claim 7

A power supply as set forth in claim 4 wherein said transistor bridge circuit comprises four like bridge arms, each including a protected transistor switching element, said switching element compRising, in combination, a first silicon diode connected in parallel with the series combination of the collector-emitter path of a germanium transistor and a second silicon diode, said second diode being poled to block reverse currents through said transistor while said first diode is poled to conduct said reverse currents around said series combination.

Claim 8

A power supply as set forth in claim 4 further including means for preventing the application of said firing signal to said control electrode unless said first source is supplying an operating potential to said generator and the signal applied to the switching signal input to said bridge exceeds a predetermined value.

Claim 9

A power supply of the class comprising, in combination, a source of alternating current energy, means including at least one controlled-rectifier for periodically conducting energy from said source to a load circuit, and means for generating periodic firing signals for initiating conduction through said controlled-rectifier, said generating means including means responsive to a control signal for varying the timing of said firing signals relative to the waveform of said alternating current to thereby vary the amount of energy delivered to said load, wherein the improvement comprises, in combination, means synchronized with said alternating current for generating a periodic timing signal having a fixed amplitude and waveform, both of which are substantially independent of variations in the magnitude of either said alternating current energy or the energy delivered to said load, a threshold device for generating said firing signals where the instantaneous magnitude of said periodic timing signal equals a threshold level, said device including means for shifting said threshold level relative to said waveform in response to said control signal to vary the timing of said firing signal; and coupling means for varying the magnitude of said control signal in response to variations in at least one parameter of the energy delivered to said load circuit, said coupling means including filtering means for minimizing the effect of momentary variations in said parameter on said control signal, said filtering means comprising the parallel combination of a resistor and a Zener diode connected between said load circuit and a filter capacitor, said Zener diode providing an additional current path for charging said filter capacitor when voltage first appears on said load circuit.

Claim 10

A power supply of the class comprising, in combination, a source of alternating current energy, means including at least one controlled-rectifier for periodically conducting energy from said source to a load circuit, and means for generating periodic firing signals for initiating conduction through said controlled-rectifier, said generating means including means responsive to a control signal for varying the timing of said firing signals relative to the waveform of said alternating current to thereby vary the amount of energy delivered to said load, wherein the improvement comprises, in combination, means synchronized with said alternating current for generating a periodic timing signal having a fixed amplitude and waveform, both of which are substantially independent of variations in the magnitude of either said alternating current energy or the energy delivered to said load, a threshold device for generating said firing signals where the instantaneous magnitude of said periodic timing signal equals a threshold level, said device including means for shifting said threshold level relative to said waveform in response to said control signal to vary the timing of said firing signal; and coupling means for varying the magnitude of said control signal in response to variations in at least one parameter of the energy delivered to said load circuit, said coupling means including filtering means for minimizing the effect of momentary variations in said parameter on said control signal, said filtering means comprising the parallel combination of a resistor and a Zener diode connected between said load circuit and a filter capacitor, said Zener diode providing an additional current path for charging said filter capacitor when voltage first appears on said load circuit.

Claim 11

In a power supply system, apparatus for detecting the presence of an overcurrent condition in a protected circuit which comprises, in combination, a current sensing resistor connected in series with said circuit, the series combination of a Zener diode, a second resistor and a capacitor connected in parallel with said current sensing resistor, a conventional diode connected in parallel with the series combination of said second resistor on said Zener diode, and a threshold device for detecting the presence of overcurrent conditions connected to respond to voltages across said capacitor in excess of a predetermined value.

Claim 12

In a power supply system, apparatus for detecting the presence of an overcurrent condition in a protected circuit which comprises, in combination, a current sensing resistor connected in series with said circuit, the series combination of a Zener diode, a second resistor and a capacitor connected in parallel with said current sensing resistor, a conventional diode connected in parallel with the series combination of said second resistor on said Zener diode, and a threshold device for detecting the presence of overcurrent conditions connected to respond to voltages across said capacitor in excess of a predetermined value.