DD291426A5 - ELECTRONICALLY CONTROLLABLE POWER SOURCE FOR IMPULSE LASER - Google Patents

Abstract

The invention relates to an electronically controllable power source for pulsed laser medium and large power, which are used for electrical engineering purposes. It is based on a series resonant circuit and comprises a mains rectifier, a buffer, an inverter and a secondary rectifier, and is characterized in that a clock-controlled electronic switch is provided for exciting the series resonant circuit and further in parallel with the capacitor of the series resonant circuit, the series connection of a DC reactor Winding of the number of turns N1 and a valve is arranged, wherein the DC reactor additionally has a demagnetization winding of the number of turns N2, which is connected via a further valve with the aforementioned buffer. {Power source, electronically controllable; Pulse laser; Machining, electrotechnical; Series resonant circuit; DC reactor; demagnetizing}

Description

Field of application of the invention

The invention relates to an electronically stouorbaro current source for pulsed laser medium and high power, which are used for electrical engineering purposes.

Characteristic of the known state of the art

Pulse lasers are increasingly being used to solve different material handling tasks, e.g. For lettering, marking, photolithography and the like.

In order to be able to produce stable results with high efficiency, constant pulse energies must be ensured with high efficiency of the excitation and high repetition frequency. The power sources for charging the energy storage must therefore be synchronized and short-circuit proof.

In EP-PS 0067464 such a working according to the inverter principle current source is described, which has a relatively high control technology stability. Due to the circuit, the drive costs for operation in pulsed lasers are high and the robustness of the overall system is low.

A higher Wochselrichterfrequenz and thus low transformer dimensions but still considerable circuit complexity of control electronics and monitoring devices characterize such solutions as from DE-PS 261250. Due to the power electronic switches used and the circuit principles of the above solutions, the frequency and robustness of the devices are limited at the same time unsatisfactory high mass and large space requirements. The robustness against load jumps and electromagnetic interference pulses is, however, an essential use value of the laser current source, since the pulse lasers to be supplied represent a source of considerable disturbances. As a result, the scope of the conventional solutions for the power supply of pulsed lasers is significantly limited.

Object of the invention

The aim of the invention is to provide an electronically controllable current source for pulsed laser, which has a wider range of applications with reduced circuit complexity.

Explanation of the essence of the invention

The object is to develop an electronically controllable current source for pulsed laser, which has a greater robustness with a reduced number of components and increased inverter frequency and at the same time has reduced mass and smaller space requirements.

According to the invention the object is achieved in that the dio on aomain of a series resonant circuit and a mains rectifier, a buffer, an inverter and a Sokundärgleichrichter having electronic stouorbaro current source for pulse laser has the following additional features:

- There is a clock-controlled electronic switch for excitation of the series resonant circuit, which is formed of a capacitor and a transformer for load matching, available.

- Furthermore, in parallel with the aforementioned capacitor, the series connection of a DC reactor with a winding of the number of turns N1 and a valve is required, wherein the DC reactor additionally has a demagnetization winding of the number of turns N 2, is connected via a further valve with the aforementioned buffer.

The mode of operation of the invention includes the following relationships:

The series resonant circuit is periodically excited by the electronic switch, which in turn is controlled by a clock generator. In the blocking phase of the switch, the DC reactor compensates for the energy loss of the resonant circuit. When a capacitor voltage determined by the ratio N1 / N 2 of the number of turns of the DC reactor windings is exceeded, the energy of the reactor is output to the buffer via the demagnetization winding.

An advantage of the circuit according to the invention is that only one Schaltor must be controlled with a fixed frequency. This switch can be designed both as a transistor and as a thyristor. By förungsgomäßo load the switch is at glolchon parameters dos switch gogonübor conventional solutions dio doppolto inverter frequency reachable.

This increase in frequency, in conjunction with the precursor locations, leads to increased mass and volume production. The oinfacho circuit structure and the warranty clsor Schaltorgrenzwerte by the load croc lead to a significant increase in the robustness dor orungsungsgomäßon electronically controllable power source for Impulslascr.

embodiment The invention will be explained in the following to oinom Ausführungsboispiol close. The drawing shows the principle circuit of the invention electronically stouorbaron current source for zugohörigo drawing Impulslasor. The operation of the power source according to the invention is the following: From a rectifier 1, the Notzwechsolspannung is converted into a DC voltage and smoothed in a buffer 2. The core of the power source is a Roischwingkrois, consisting of a capacitor 3 as a resonant circuit capacitance, a Transformer 4 and oinom electronic Schaltor 5, which is controlled by oinom clock generator 6. The energy loss dos Reihonschwingkreisos is over oino two windings Gloichstromdrossol 7, connected to a valve 8,

periodically balanced. To limit the voltage stress of the switch 5 or of the capacitor 3 in the start-stop

Botrieb the excess energy of Gloichstromdrossol 7 is delivered via the further valve 9 to the buffer 2.

Claims (1)

Electronically controllable current source for pulse lasers, based on a series resonant circuit and a mains rectifier comprising a buffer, an inverter and a secondary rectifier, characterized in that a clock-controlled electronic switch (5) for excitation of the series resonant circuit consisting of a capacitor (3) and a transformer (4) is formed for load matching, is present and that further in parallel to the aforementioned capacitor (3), the series connection of a DC reactor (7) with a winding of the number of turns N1 and a valve (8) is arranged, wherein the DC reactor (7) in addition a Demagnetisierungswicklung the number of turns N 2, which is connected via a further valve (9) with the aforementioned buffer. For this 1 page drawing