Oscillator for a powder spray coating device

An oscillator for providing an oscillating voltage for a powder spray coating device, the oscillator comprising:

• a first signal generator for generating an intermediate circuit voltage;
• a second signal generator for generating a modulation signal;
• a modulation signal isolating element, connected to the second signal generator;
• a modulation unit for generating an oscillator voltage;
• a first terminal for outputting the oscillator voltage to a powder spray coating device;
• a second terminal for returning the used oscillator voltage to a reference potential, in particular earth potential,
• wherein the modulation unit being configured for generating the oscillator voltage by modulation of the intermediate circuit voltage with the modulation signal;
• and
• a first voltage monitoring device configured for continuously measuring the oscillator voltage, comparing the oscillator voltage with at least one specified or specifiable oscillator voltage reference value and, if a first comparison criterion is satisfied, outputting a modulation isolating signal to the modulation signal isolating element,
• the oscillator also having an intermediate circuit voltage isolating element, connected to the first signal generator, and a second voltage monitoring device being provided, designed for continuously measuring the intermediate circuit voltage, comparing the intermediate circuit voltage with at least one specified or specifiable intermediate circuit voltage reference value and, if a second comparison criterion is satisfied, outputting an intermediate circuit voltage isolating signal to the intermediate circuit voltage isolating element.

An oscillator for providing an oscillating voltage for a powder spray coating device, the oscillator having:

• a first signal generator for generating an intermediate circuit voltage;
• a second signal generator for generating a modulation signal;
• a modulation signal isolating element, connected to the second signal generator;
• a modulation unit for generating an oscillator voltage;
• a first terminal for outputting the oscillator voltage to a powder spray coating device;
• a second terminal for returning the used oscillator voltage to a reference potential, in particular earth potential,
• the modulation unit being designed for generating the oscillator voltage by modulation of the intermediate circuit voltage with the modulation signal;
• and
• a first voltage monitoring device being provided, designed for continuously measuring the oscillator voltage, comparing it with at least one specified or specifiable oscillator voltage reference value and, if a first comparison criterion is satisfied, outputting a modulation isolating signal to the modulation signal isolating element,
• the modulation signal isolating element and/or the intermediate circuit voltage isolating element each being formed as a transistor isolating element, in particular as a fast-switching field-effect transistor isolating element.

An oscillator for providing an oscillating voltage for a powder spray coating device, the oscillator comprising:

• a first signal generator for generating an intermediate circuit voltage;
• a second signal generator for generating a modulation signal;
• a modulation signal isolating element, connected to the second signal generator;
• a modulation unit for generating an oscillator voltage;
• a first terminal for outputting the oscillator voltage to a powder spray coating device;
• a second terminal for returning the used oscillator voltage to a reference potential, in particular earth potential,
• wherein the modulation unit is configured for generating the oscillator voltage by modulation of the intermediate circuit voltage with the modulation signal;
• a first voltage monitoring device configured for continuously measuring the oscillator voltage, comparing the oscillator voltage with at least one specified or specifiable oscillator voltage reference value and, if a first comparison criterion is satisfied, outputting a modulation isolating signal to the modulation signal isolating element;
• and
• an earth current monitoring device, designed for continuously measuring an earth current, in particular an earth current between the reference potential and a protective conductor potential, and outputting an earth current monitoring isolating signal to the modulation signal isolating element and/or an earth current monitoring isolating signal to the intermediate circuit voltage isolating element if a previously specified or specifiable maximum earth current is exceeded.

A method for providing an oscillating voltage provided at an oscillator for a powder spray coating device, the method comprising:

• generating an intermediate circuit voltage by a first signal generator;
• generating a modulation signal by a second signal generator;
• generating an oscillator voltage by a modulation unit;
• interrupting an electrical connection between the second signal generator and the modulation unit in the presence of a modulation isolating signal by a modulation signal isolating element connected to the second signal generator;
• outputting the oscillator voltage to a powder spray coating device by a first terminal;
• and
• returning the used oscillator voltage to a reference potential, in particular earth potential, by a second terminal,
• wherein the modulation unit generates the oscillator voltage by modulation of the intermediate circuit voltage with the modulation signal, and
• a first voltage monitoring device performs the steps of:
• continuously measuring the oscillator voltage;
• comparing the measured oscillator voltage with at least one specified or specifiable oscillator voltage reference value;
• establishing whether or not a first comparison criterion is satisfied;
• if the first comparison criterion is satisfied:
• outputting a modulation isolating signal to the modulation signal isolating element.