Circuit for displaying the relative voltage at the output electrode of an electrostatically aided coating material atomizer

A coating dispensing device including a trigger assembly for actuating the coating dispensing device to dispense coating material, and a nozzle through which the coating material is dispensed, a source of voltage, a voltage multiplier for multiplying the voltage, the voltage multiplier coupled to the source, an output terminal of the voltage multiplier charged to a high-magnitude electrostatic potential and adapted to charge coating material as the coating material is dispensed from the dispensing device, and a circuit for providing a visual indication of the voltage at the output terminal of the voltage multiplier, the circuit comprising a first impedance across which a portion of the voltage at the output terminal of the voltage multiplier appears, a differential amplifier having a non-inverting input terminal (+), an inverting input terminal (−) and an output terminal, one of the + and − input terminals of the differential amplifier coupled to the voltage source and the other of the + and − input terminals of the differential amplifier coupled to the first impedance, and the output terminal of the differential amplifier coupled to a light source for providing a visual indication of the voltage at the output terminal of the voltage multiplier, and a buffer amplifier having an input terminal coupled to the first impedance and an output terminal coupled to said other of the + and − input terminals of the differential amplifier, the buffer amplifier isolating the first impedance from said other of the + and − input terminals of the differential amplifier.

A coating dispensing device including a trigger assembly for actuating the coating dispensing device to dispense coating material, and a nozzle through which the coating material is dispensed, a source of voltage, a voltage multiplier for multiplying the voltage, the voltage multiplier coupled to the source, an output terminal of the voltage multiplier charged to a high-magnitude electrostatic potential and adapted to charge coating material as the coating material is dispensed from the dispensing device, and a circuit for providing a visual indication of the voltage at the output terminal of the voltage multiplier, the circuit comprising a first impedance across which a portion of the voltage at the output terminal of the voltage multiplier appears, a differential amplifier having a non-inverting input terminal (+), an inverting input terminal (−) and an output terminal, one of the + and − input terminals of the differential amplifier coupled to the voltage source and the other of the + and − input terminals of the differential amplifier coupled to the first impedance, and the output terminal of the differential amplifier coupled to a light source for providing a visual indication of the voltage at the output terminal of the voltage multiplier, the voltage multiplier including an oscillator, a transformer coupled to the oscillator, and a voltage multiplier cascade coupled to the transformer, the voltage multiplier cascade coupled to the output terminal of the voltage multiplier through a second impedance whose real component is on the order of about 2×103 to about 4×103 times a real component of the first impedance.

A coating dispensing device including a trigger assembly for actuating the coating dispensing device to dispense coating material, and a nozzle through which the coating material is dispensed, a source of voltage, a voltage multiplier for multiplying the voltage, the voltage multiplier coupled to the source, an output terminal of the voltage multiplier charged to a high-magnitude electrostatic potential and adapted to charge coating material as the coating material is dispensed from the dispensing device, and a circuit for providing a visual indication of the voltage at the output terminal of the voltage multiplier, the circuit comprising a first impedance across which a portion of the voltage at the output terminal of the voltage multiplier appears, a differential amplifier having a non-inverting input terminal (+), an inverting input terminal (−) and an output terminal, one of the + and − input terminals of the differential amplifier coupled to the voltage source and the other of the + and − input terminals of the differential amplifier coupled to the first impedance, and the output terminal of the differential amplifier coupled to a light source for providing a visual indication of the voltage at the output terminal of the voltage multiplier, the voltage multiplier including an oscillator, a transformer coupled to the oscillator, and a voltage multiplier cascade coupled to the transformer, the first impedance comprising a parallel combination of a resistor and a capacitor.