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US 4,908,754 AGranted
Trigger and control means for bridge inverter
OwnerOle K. Nilsseninventor
Life of this patent
Estimating the term…
Abstract
In an inverter-type power supply, a self-oscillating full-bridge inverter is powered by unfiltered full-wave-rectified 120 Volt/60 Hz power line voltage and controllably triggered into oscillation each half-cycle of the power line voltage by way of simultaneously triggering two of the bridge's four transistors into conduction simultaneously. This is accomplished by way of discharging a charged-up capacitor by way of a Diac through a special trigger winding on each of two saturable current feedback transformers; each of which controls a pair of the bridge transistors.
Claims20
An arrangement comprising:
- a source of DC voltage;
- bridge inverter means connected with the source of DC voltage and operative, but only when the magnitude of the DC voltage exceeds a threshold level and then only after having been provided with a trigger signal at a trigger input, to self-oscillate by way of positive feedback means and to provide an output of AC voltage at a pair of output terminals, the inverter means having a first and a second pair of electronic switching means, each electronic switching means having a control input, the trigger input being connected in circuit with the control input of at least two of the electronic switching means;
- and
- trigger means connected with the trigger input and operative to provide the trigger signal.
1 more element
An arrangement comprising:
- a source providing a DC voltage between a B+ terminal and a B- terminal;
- bridge inverter means having:
- (i) a first transistor means connected between the B+ terminal and a first junction, and a second transistor means connected between the first junction and the B- terminal, and (ii) a third transistor means connected between the B+ terminal and a second junction, and a fourth transistor means connected between the second junction and the B- terminal;
- each transistor means having a control input;
- a positive feedback means being connected in circuit between the first junction, the second junction, and the control input of each transistor means, the positive feedback means having a trigger input;
- the bridge inverter means being operative by way of the positive feedback means to self-oscillate and to provide an AC voltage output from a pair of AC output terminals connected with the first and the second junction, but only as long as the magnitude of the DC voltage is above a threshold level and then only after having been provided with a trigger pulse at a trigger input;
- and
- pulse control means connected with the trigger input and operative to provide a trigger pulse to the trigger input.
5 more elements
An arrangement comprising:
- a source of AC voltage;
- rectifier means connected with the source of AC voltage and operative to provide a DC voltage consisting of periodic unidirectional voltage pulses;
- full bridge inverter means having four transistors connected in bridge configuration between the DC terminals and operative to provide a high-frequency voltage at an inverter output, but only as long as the magnitude of the DC voltage exceeds a threshold level and then only after having been provided with a trigger pulse at a trigger input;
- whereby:
- (i) after having been provided with a trigger pulse while the instantaneous magnitude of the DC voltage exceeded the threshold level, the high-frequency voltage will indeed be provided, but only as long as the instantaneous magnitude of the DC voltage exceeds the threshold level, and (ii) the high-frequency voltage will cease being provided at some point during each unidirectional voltage pulse, namely whenever the instantaneous magnitude of the DC voltage falls below the threshold level;
- trigger means connected with the trigger input and operative to provide a trigger pulse to the trigger input.
3 more elements
The arrangement of:
- a source operable to provide a DC voltage substantially consisting of periodic relatively low-frequency sinuoidally-shaped unidirectional voltage pulses;
- full bridge inverter circuit powered from the DC voltage and operative to provide an output of high-frequency AC voltage, but only as long as the instantaneous magnitude of the DC voltage exceeds a threshold level and then only after having been provided with a triggering impulse at a trigger input;
- and
- trigger means connected with the trigger input and operative to provide periodic triggering impulses thereto, thereby to cause the full bridge inverter circuit to provide a burst of high-frequency AC voltage for each unidirectional voltage pulse.
1 more element
Dependencies are inferred from the claim text.