Corona power supply circuit

Claim 2

A portable power supply for producing a high corona output when coupled to a D.C. power source including in combination: oscillator means operative to develop first oscillations; control means coupled to said oscillator means and operative to develop second oscillations in response to said first oscillations and a corona signal indicating a corona output below a predetermined level; pulse-shaper means coupled to said control means and operative to develop a first voltage pulse having one polarity in response to a first half of each cycle of said second oscillations and to develop a second voltage pulse having the opposite polarity in response to the second half of each cycle of said second oscillations, said pulse-shaper means being operative to draw substantially all operating current during said first half of each cycle of said second oscillations and substantially no operating current during the second half of each cycle of said second oscillations; multiplier means coupled to said pulse-shaper means and operative only in response to said first and second voltage pulses coupled thereto to develop said corona output; means for coupling said corona signal from said multiplier means to said control means.

Claim 3

The power supply of claim 1 wherein said oscillator means is an astable multivibrator.

Claim 4

The power supply of claim 1 wherein said control means include, detector means coupled to said means for coupling said corona signal from said multiplier means and operative to develop a detection signal in response to said corona signal being below said predetermined level, and gate means coupled to said detector means and said oscillator means and operative to develop said second oscillations in response to said first oscillations and said detection signal.

Claim 5

The power supply of claim 3 wherein said gate means is a NAND GATE.

Claim 6

The power supply of claim 3 wherein said detector means include, sensing means for developing a sensing voltage which varies in accordance with said corona signal, and second gate means coupled to said sensing means and operative to develop said detection signal when said sensing voltage is below a predetermined level.

Claim 7

The power supply of claim 5 wherein said second gate means include a NAND gate.

Claim 8

The power supply of claim 5 wherein said sensing means include, resistance means for sensing a current proportional to said corona signal and for developing said sensing voltage which varies in accordance with said current, said second gate means operative in response to said sensing voltage being above a threshold, indicating presence of a desired corona output, to terminate said detection signal and operative in response to a sensing voltage below said threshold, indicating a corona signal below the desired corona output to develop said detection signal.

Claim 9

The power supply of claim 7 wherein said second gate means include a semiconductor gate and circuit means coupled to said gate and operative to producing a feedback characteristic in the operation of said gate.

Claim 10

The power supply of claim 8 wherein said semiconductor gate is a NAND gate having at least one input and an output and said circuit means include resistance means coupled from said output to said input and capacitance means coupled from said input to ground potential.

Claim 11

The power supply of claim 1 wherein said multiplier means is a voltage octupler.

Claim 12

The power supply of claim 1 wherein said pulse-shaper means include, switch means coupled to said control means and transformer means coupled to said switch means, said switch means operative in response to said first half of each cycle of second oscillations to turn on drawing operating current therethrough and saturation current therethrough and through said transformer means, said switch means operative in response to each second half cycle of said second oscillations to turn off drawing substantially no current and terminating said saturation current therethrough and through said transformer means, said transformer means responsive to said saturation current to develop a first voltage pulse and responsive to said saturation current termination to develop a second voltage pulse.

Claim 13

The power supply of claim 11 wherein said transformer means include a transformer having primary and secondary windings, said primary winding being coupled in series between said power source and said switch means, said first and second voltage pulses being developed across section secondary winding.

Claim 14

The power supply of claim 12 wherein said transformer saturates in respnse to said saturation current and induces said first voltage pulse across said secondary, said transformer inducing said second voltage pulse across said secondary winding in response to termination of said saturation current.

Claim 15

The power supply of claim 11 wherein said switch means include, a first semiconductor means coupled to said control means, said first semiconductor means being normally nonconductive and being operative only in response to said first half of each cycle of said second oscillations to conduct, second semiconductor means coupled to said first semiconductor means and said transformer means and operative only in response to conduction of said first semiconductor means to draw said saturation current therethrough and through said transformer means.

Claim 16

The power supply of claim 14 wherein said transformer means include a transformer having a primary and secondary winding, said primary winding being coupled in series between said second semiconductor means and said power source, said first and second voltage pulses being developed across said secondary winding.

Claim 17

The power supply of claim 15 wherein said transformer saturates in response to said saturation current and induces said first voltage pulse across said secondary, said transformer inducing the second voltage pulse across said secondary winding in response to termination of said saturation current.

Claim 18

The power supply of claim 14 wherein said first semiconductor means include a first transistor and said second semiconductor means include second and third transistors with the second transistor arranged as an emitter follower.

Claim 19

The power supply of claim 17 wherein said second semiconductor means include voltage protection means coupled across said third transistor for protecting same from excessive voltage.

Claim 20

The power supply of claim 1 wherein said corona output is a corona voltage and said corona signal is a corona current which varies in accordance with corona voltage and wherein said control means include, detector means coupled to said means for coupling said corona signal from said multiplier means and operative to develop a detection signal in response to said corona current being below said predetermined level, and gate means coupled to said detector means and said oscillator means and operative to develop said second oscillations in response to said first oscillations and said detection signal.

Claim 21

The power supply of claim 19 wherein said detector means include, sensing means for developing a sensing voltage which varies in accordance with said corona current and second gate means coupled to said sensing means and operative to develop said detection signal when said sensing voltage is below a predetermined level.

Claim 22

The power supply of claim 20 wherein said sensing means include, resistance means for developing said sensing voltage which varies in accordance with said corona current, said second gate means operative in response to said sensing voltage being above a threshold, indicating presence of a desired corona current, to terminate said detection signal and operative in response to a sensing voltage below said threshod, indicating a corona current below the desired corona current to develop said detection signal.

Claim 23

A portable power supply for producing a high corona voltage including in combination: input means connectable to a source of D.C. voltage for receiving operating current and voltage therefrom; oscillator means coupled to said input means and operative to develop oscillations in response to connection to said source of D.C. voltage; pulse-shaper means coupled to said oscillator means and said input means and operative to develop a first voltage pulse having one polarity in response to a first half of each cycle of said oscillations and to develop a second voltage pulse having the opposite polarity in response to the second half of each cycle of said oscillations, said pulse-shaper means being operative to draw substantially all operating current during said first half of each cycle of said oscillations and substantially no operating current during the second half of each cycle of said oscillations; multiplier means coupled to said pulse-shaper means and operative only in response to said first and second voltage pulses coupled thereto to develop said corona voltage, said corona voltage reaching a particular amplitude in response to said pulses; and control means coupled between said oscillator means and said pulse shaper means and coupled to said multiplier means, said control means operative in response to a corona voltage below said particular amplitude to couple said oscillations from said oscillator means to said pulse-shaper means and operative in response to a corona voltage above said particular amplitude to inhibit passage of said oscillations from said oscillator means to said pulse-shaper means.

Claim 24

A portable power supply for producing a high corona voltage including in combination: input means connectable to a source of D.C. voltage for receiving operating current and voltage therefrom; oscillator means coupled to said input means and operative to develop oscillations in response to connection to said source of D.C. voltage; pulse-shaper means coupled to said oscillator means and said input means and operative to develop a first voltage pulse having one polarity in response to a first half of each cycle of said oscillations and to develop a second voltage pulse having the opposite polarity in response to the second half of each cycle of said oscillations, said pulse-shaper means being operative to draw substantially all operating current during said first half of each cycle of said oscillations and substantially no operating current during the second half of each cycle of said oscillations; multiplier means coupled to said pulse-shaper means and operative only in response to said first and second voltage pulses coupled thereto to develop said corona voltage, said corona voltage reaching a particular amplitude in response to said pulses; and control means coupled between said oscillator means and said pulse shaper means and coupled to said multiplier means, said control means operative in response to a corona voltage below said particular amplitude to couple said oscillations from said oscillator means to said pulse-shaper means and operative in response to a corona voltage above said particular amplitude to inhibit passage of said oscillations from said oscillator means to said pulse-shaper means.

Claim 25

The power supply of claim 22 wherein a corona load current varies in accordance with said corona voltage and wherein said control means include, detector means coupled to said multiplier means and operative in response to said corona load current being less than a predetermined current to develop a detection signal, and gate means coupled to said detector means and said oscillator means and operative in response to said detection signal to couple said oscillations from said oscillator means to said pulse-shaper means and operative in response to the absence of said detection signal to inhibit passage of said oscillations from said oscillator means to said pulse-shaper means.

Claim 26

The power sypply of claim 23 wherein said detector means include sensing means for developing a sensing voltage which varies in accordance with said corona current and gate means coupled to said sensing means and operative to develop said detection signal when said sensing voltage is below a predetermined level.

Claim 27

The power supply of claim 24 wherein said pulse-shaper means include, switch means coupled to said control means and transformer means coupled to said switch means, said switch means operative in response to said first half of each cycle of oscillations to turn on drawing operating current therethrough and saturation current therethrough and through said transformer means, said switch means operative in response to each second half cycle of oscillations to turn off drawing substantially no operating current and terminating said saturation current therethrough and through said transformer means, said transformer means response to said saturation current to develop a first voltage pulse and operative in response to said saturation current termination to develop a second voltage pulse.