1. Manuals
  2. Brands
  3. EHT Manuals
  4. Pulse Generator
  5. NSP Series
  6. User manual

EHT NSP Series User Manual

Low power nanosecond pulser
Hide thumbs
Table of Contents

Advertisement

Quick Links

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the NSP Series and is the answer not in the manual?

Questions and answers

Summary of Contents for EHT NSP Series

  • Page 2 !!! Extreme Danger !!! The energy levels, voltages, and/or currents used and generated by the power supply and pulser can be lethal. Supply and pulser should only be operated by qualified personnel. Do not attempt to operate the power supply and pulser unless the user has sufficient knowledge of the dangers and hazards of working with high voltage.
  • Page 3 Failure to follow these warnings can result in immediate and catastrophic failure of the Nanosecond Pulser (NSP). Such failure results in characteristic internal damage, and is not covered by the EHT warranty. If you have any questions regarding safe operation, please contact EHT for guidance prior to such operation.

  • Page 4: Table Of Contents

    Table of Contents Warranty ............................4 Patents ..............................5 General Information .......................... 6 3.1 Specifications ..........................7 3.2 Operational Space ......................... 8 3.3 Output Resistor Stage........................10 Controls and Connectors ......................... 12 4.1 Front Panel ..........................12 4.2 Back Panel ..........................13 Preparation for Use .........................

  • Page 5: Patents

    1 Warranty EHT warrants that all EHT Electronics Ltd. manufactured equipment will be free of any defect in materials or workmanship for the period of (1) year. The warranty is extended to customers and applies to all EHT manufactured equipment purchased, installed, and used for the purpose for which such equipment was originally designed.

  • Page 6: General Information

    3 General Information The NSP series of power supplies are nanosecond pulsers with an output voltage range of 0-30 kV, pulse widths of 20-500 ns, and pulse repetition frequencies up to 30 kHz. Each parameter is independently adjustable through a continuous range, although not all the maximum parameters may be reached simultaneously, depending on the load that is being driven.

  • Page 7: Specifications

    3.1 Specifications The part numbering for the standard NSP series of power supplies is as follows: The output voltage, rise time, and pulse width are load dependent. The stated rise times are measured into a high impedance load at the output connector.

  • Page 8: Operational Space

    3.2 Operational Space The NSP voltage, pulse width, and pulse repetition frequency are all individually adjustable. For the load types indicated, the following figures show the accessible operating space. • The minimum pulse width is measured at maximum output voltage, defined as the full width at half-maximum (FWHM).
  • Page 9 Figure 3. Available Operating Space for the NSP-120-20-P-500-L Figure 4. Available Operating Space for the NSP-120-30-P-500-H P: 206.402.5241 E: info@eagleharbortech.com | 169 Western Ave W, Seattle, WA 98119 | www.eagleharbortech.com Page 9 of 32...

  • Page 10: Output Resistor Stage

    3.3 Output Resistor Stage All versions of the NSP series have an output resistor stage. The exact configuration and values of the resistors depends on the exact model of the NSP ordered, but they all contain a parallel output resistor...
  • Page 11 3.3.2 Output Resistor Stage for Grounded Units (-P and –N) Grounded versions of the NSP contain an asymmetric resistive output stage as shown in Figure 6. The effective output impedance of the NSP is R . Note that if your NSP was purchased prior to 2019, please contact the manufacturer for values.

  • Page 12: Controls And Connectors

    4 Controls and Connectors 4.1 Front Panel A description of the front panel controls, indicators, and connections is given below. Figure 7. NSP-120-20-F Front Panel 1. Power LED: Green when AC power is switched on. 2. HV On LED: Red when the HV Output is enabled. 3.

  • Page 13: Back Panel

    9. Pulse Repetition Frequency – Base Control: In Internal Mode, this dial allows the user to control the base pulse repetition frequency. If the user wants to operate under the single shot mode, this knob must be dialed to Single Pulse. In External Mode, this dial does nothing. 10.

  • Page 14: Preparation For Use

    5 Preparation for Use 5.1 Unpacking Please verify that all items are present and inspect for damage during shipping. 1. EHT NSP series power supply 2. HV output cables, one red and one black 3. Standard AC power cord for the NSP 4.

  • Page 15: Operational Setup

    5.2 Operational Setup 1. Place the NSP on a bench near the load. Do not block the exhaust fan or the intake vents on the bottom side of the unit. If the exhaust fan or vents are blocked, the pulser may overheat. 2.

  • Page 16: Operation Instructions

    6 Operation Instructions The NSP may be operated in three different modes: Free-running, Triggered, and External. However, certain steps are common to all modes. 6.1 Turning on the NSP 1. Set AC Switch on the rear panel to On. The green Power LED will illuminate. 2.

  • Page 17: Free-Running Mode Operation

    6.4 Free-running Mode Operation In free running mode, the NSP will continuously output pulses as set by the pulse width, frequency, and voltage knobs on the front panel. To operate in Free-running mode, ensure that the Internal/External switch is set to “Internal”, and that the Base Pulse Repetition Frequency Knob is in any position except “Single/Trigger”.

  • Page 18: External Mode Operation (Optional)

    As with Triggered Mode, to provide noise immunity and safety, the external control input is fiber- optically coupled. EHT provides a fiber optic driver that is used to send the appropriate pulses to the NSP. See additional information about the FT-1 in section 7. Each rising edge of a signal going into the FT-1 will correspond to a single output pulse of the NSP.
  • Page 19 External Control Pulse Width (ns) Figure 9. Input pulse width vs output pulse width for NSP-120-20-F P: 206.402.5241 E: info@eagleharbortech.com | 169 Western Ave W, Seattle, WA 98119 | www.eagleharbortech.com Page 19 of 32...
  • Page 20 5 V input gate signal from a source capable of driving the 50 Ω input load to 5 V. The FT-1 is powered by a 5 V/1 A power supply provided by EHT. The input trigger signal must be a clean smooth trigger, with no overshoots or oscillations and have a rise time and fall time of less than 20 ns.

  • Page 21: Troubleshooting

    8 Troubleshooting 8.1 General Problem: The rear panel AC Switch is turned to the On (I) position, but the fan does not turn on and none of the front panel LED indicators illuminate. Solution: • Ensure that the AC equipment cord included with the unit is receiving power and is firmly seated in the rear panel AC Power Receptacle.

  • Page 22: Internal Mode

    Problem: Plasma discharge (DBD or arc) does not occur. Solution: • Measure the output voltage or current. • If the output is shorted, no voltage will develop across the load, but the current will display a flattop current (~27 A at the full 20 kV front panel setting in the case of an NSP-120-20-N, for example) as dictated by the output impedance of the unit (745 Ω).

  • Page 23: External Mode

    8.3 External Mode Problem: The rear panel AC Switch is in the On (I) position and the front panel HV Output Switch in the Enable position, but there is no output pulse despite a verified input pulse. Solution: • Ensure that the front panel Mode Switch is set to External. •...

  • Page 24: Power Cycle Steps

    8.4 Power Cycle Steps 1. Ensure that the front panel HV Output Switch is in the Disable position. 2. Set the rear panel AC Switch to Off (O). 3. Wait for approximately 30 seconds to allow internal capacitance to drain. 4.
  • Page 25 10. If no output pulse is detected, turn the Pulse Repetition Frequency – Base knob to 2 Hz. If an output pulse is detected in this mode (every 0.5 seconds), but was not detected when set to Single Pulse, contact Eagle Harbor Technologies. 11.

  • Page 26: Appendix

    9 Appendix For a detailed explanation of measuring fast high voltage pulses, see the Nanosecond Pulse Measurement White Paper at http://www.eagleharbortech.com/support. The following waveforms from the NSP were measured using: • An isolated/floating Tektronix DPO 2024 Digital Phosphor Oscilloscope • Pearson Current Monitor 6585 with 50 Ω...

  • Page 27: Capacitive Voltage Divider Waveforms

    Figure 13. Minimum (left) and maximum pulse widths at 20 kV. 9.2 Capacitive Voltage Divider Waveforms The user can measure the full voltage output using a capacitive voltage divider. The waveform below shows that measuring the output voltage with a capacitive voltage divider with a small total capacitance (1 pF) produces similar results as using the internal R (not user accessible).

  • Page 28: Dielectric Barrier Discharge Waveform

    9.3 Dielectric Barrier Discharge Waveform The NSP can be used to drive a dielectric barrier discharge (DBD). The voltage and current driving a DBD can be measured using the 1 pF voltage divider and fast current monitor. The DBD had a capacitance of 8 pF.

  • Page 29: Arc Waveforms

    9.4 Arc Waveforms The NSP can be used to drive and turn off arcs. Using the 1 pF voltage divider and current monitor, the load voltage and current can be measured. This waveform shows the voltage reaching a peak before the discharge occurs and current begins to flow.
  • Page 30 Figure 20. Voltage (blue) and current (purple) for minimum (left) and maximum pulse widths across a 10 pF 1:9 capacitive voltage divider. Figure 21. Maximum pulse width on a shorted output, demonstrating the maximum dI/dt and current for the unit (1.1 A/ns up to a 34 A peak with a flat-top of approximately 30 A). Please note that the vertical scale reported by the oscilloscope is incorrect.

  • Page 31: Nsp-120-20-P-500 Output Waveforms

    9.6 NSP-120-20-P-500 Output Waveforms Waveforms specific to this unit. Unless otherwise specified, all shots were taken at full voltage and with 6” output cables unless otherwise specified. This unit has recently undergone a redesign and these waveforms are no longer accurate. Figure 22.

  • Page 32: User Notes

    Figure 25. Maximum pulse width on a shorted output, demonstrating the maximum dI/dt and current for the unit (1.2 A/ns up to a flat-top of approximately 33 A). 10 User Notes P: 206.402.5241 E: info@eagleharbortech.com | 169 Western Ave W, Seattle, WA 98119 | www.eagleharbortech.com Page 32 of 32...

This manual is also suitable for:

Nsp-120-5-f-500-lNsp-120-5-f-500-hNsp-120-10-f-500-lNsp-120-10-f-500-hNsp-120-20-f-500-lNsp-120-20-f-500-h ... Show all

Table of Contents