Back to results
US 5,703,765 AGranted
Flyback converter having a regulated output voltage
AssigneeSiemens Aktiengesellschaft
InventorJosef Preis
Life of this patent
Estimating the term…
Abstract
Flyback converter has a regulating arrangement which is connected to an output and whose duty ratio is limited to a predetermined upper limit. A series circuit has a diode and an RC series circuit is connected to the rectifier diode of the main circuit (3) on the secondary side in order to supply the regulating arrangement with an auxiliary voltage which is greater than the output voltage. A further diode (44) leads from the series circuit to an output (a) of the auxiliary circuit (4). The flyback converter is suitable in particular for supplying ASICs, which require a relatively low supply voltage.
Claims19
A flyback converter, comprising:
- an electronic switch which is connected in series with a primary winding of a transformer in a main circuit on a primary side of the transformer, the electronic switch being controllable by a control device;
- on a secondary side of the transformer a main circuit which is connected to a secondary winding of the transformer, the main circuit having a first diode in a series path and an energy-storage capacitor in a subsequent parallel path, connected in parallel with an output in the transformer;
- a regulating arrangement connected to an output of the flyback converter, the regulating arrangement supplied with an auxiliary voltage, a duty ratio of the control voltage which controls the electronic switch being limited to a predetermined upper limit;
- an auxiliary circuit having an input connected to the first diode of the main circuit on the secondary side and the auxiliary circuit having one pole of an output connected to the input;
- the auxiliary circuit having an RC series circuit in a series path on the input side, a second diode in the downstream parallel path, a third diode in a series path following the parallel path, and a capacitor in parallel with the output;
- the regulating arrangement having an auxiliary voltage input supplied with an auxiliary voltage which is a sum of the output voltage of the flyback converter and the output voltage of the auxiliary circuit;
- the second diode polarized such that the second diode is reverse biased when the first diode is forward biased;
- the third diode polarized such that the third diode is reverse biased when the second diode is forward biased.
5 more elements
A flyback converter, comprising:
- an electronic switch which is connected in series with a primary winding of a transformer in a main circuit on a primary side of the transformer, the electronic switch being controllable by a control device;
- on a secondary side of the transformer a main circuit which is connected to a secondary winding of the transformer, the main circuit having a first diode in a series path and an energy-storage capacitor in a subsequent parallel path, connected in parallel with an output in the transformer;
- a regulating arrangement connected to an output of the flyback converter, the regulating arrangement supplied with an auxiliary voltage, a duty ratio of the control voltage which controls the electronic switch being limited to a predetermined upper limit;
- an auxiliary circuit having an input connected to the first diode of the main circuit on the secondary side and the auxiliary circuit having one pole of an output connected to the input;
- the auxiliary circuit having an RC series circuit in a series path on the input side, a second diode in the downstream parallel path, a third diode in a series path following the parallel path, and a capacitor in parallel with the output;
- the regulating arrangement having an auxiliary voltage input supplied with an auxiliary voltage which is a sum of the output voltage of the flyback converter and the output voltage of the auxiliary circuit;
- the second diode polarized such that the second diode is reverse biased when the first diode is forward biased;
- the third diode polarized such that the third diode is reverse biased when the second diode is forward biased;
- and
- a zener diode arranged in parallel with the output of the auxiliary circuit.
7 more elements
A flyback converter, comprising:
- an electronic switch which is connected in series with a primary winding of a transformer in a main circuit on a primary side of the transformer, the electronic switch being controllable by a control device;
- on a secondary side of the transformer a main circuit which is connected to a secondary winding of the transformer, the main circuit having a first diode in a series path and an energy-storage capacitor in a subsequent parallel path, connected in parallel with an output in the transformer;
- a regulating arrangement connected to an output of the flyback converter, the regulating arrangement supplied with an auxiliary voltage, a duty ratio of the control voltage which controls the electronic switch being limited to a predetermined upper limit;
- an auxiliary circuit having an input connected to the first diode of the main circuit on the secondary side and the auxiliary circuit having one pole of an output connected to the input;
- the auxiliary circuit having an RC series circuit in a series path on the input side, a second diode in the downstream parallel path, a third diode in a series path following the parallel path, and a capacitor in parallel with the output;
- the regulating arrangement having an auxiliary voltage input supplied with an auxiliary voltage which is a sum of the output voltage of the flyback converter and the output voltage of the auxiliary circuit;
- the second diode polarized such that the second diode is reverse biased when the first diode is forward biased;
- the third diode polarized such that the third diode is reverse biased when the second diode is forward biased;
- and
- the supply voltage input of a regulator of the regulating arrangement connected to the auxiliary voltage input of the regulating arrangement.
7 more elements
Dependencies are inferred from the claim text.