1. General Instructions 2 2. Safety 2 3. Lamp Starting Test Instrument LSTI 5 3

Transcription

1 1. General Instructions 2 2. Safety 2 3. Lamp Starting Test Instrument LSTI Components and Connections of the Front Panel (Fig. 1) Connection of the Rear Panel (Fig. 2) Operation Switching-on Synchronization and Triggering Adjustment of the Starting Pulse Connection of an EUT Technical Data Output Characteristics (Fig. 3 8) Pulse Shape (Fig. 9 14) Schematic Diagram (Fig. 15) 19 Spitzenberger + Spies GmbH & Co. KG Page 1

2 1. General Instructions This device has been shipped in perfect safety condition. However, it has to be checked for mechanical defects before the first start-up. If there is any transportation damage, please inform Spitzenberger + Spies immediately. In this case the device shall not be put into operation before contacting Spitzenberger + Spies and getting instructions how to carry on. 2. Safety The device must only be operated by instructed personnel! Before switching on the device please make sure that the line voltage and line frequency correspond to the device s. When operating the mains switch the device can already be in a mode to generate high voltage pulses. Basically, we recommend you to set the switch (6) in position OFF. When opening covers or casings, energising parts can be uncovered. Before opening the casing the device has to be disconnected from each voltage source. The casing and the chassis are connected to earth. Mains voltage 230V (+6% -10%) Mains frequency 50Hz/60Hz Mains protection 1A Releasing characteristics (recommended) C or D Fault-current circuit breaker ( recommended) 30mA Mains plug Earthing contact socket 16A Caution: The 6.3A-fuse (31) at the rear connects the output socket LOW (23) via the current shunt for the I-monitor with earth potential ( see page 9). When a fuse is damaged the contacts in the fuse socket can take HV-potential and dangerous contact voltages may occur. Before unscrewing the fuse socket all electronic connections of the socket LOW (23) have to be disconnected. Spitzenberger + Spies GmbH & Co. KG Page 2

3 3. Lamp Starting Test Instrument LSTI 5 The LSTI 5 Lamp Starting Test Instrument generates positive, approximate square-wave highvoltage pulses up to 5kV for the ignition of gas-discharge lamps. The pulses are drawn via a 1kΩ-real-internal-resistance. The circuitry of the device is characterized by the functional electric isolation of the ignition circuit ( breakdown ) and the circuit for the lamp operation. Breakdown and acceptance, respectively, of the lamp operation by means of the lamp supply voltage can be influenced independently by each other. The pulse is generated by connecting the direct voltage of a capacitor battery by means of the high voltage switch HTS (51) via the internal resistance 1kΩ with the output socket (21) for a short time. Because the high voltage pulse is not added to the lamp voltage but switched to the lamp, the pulse voltage is not dependent on the value of the lamp supply voltage. The pulse duration can be adjusted from 0.5µs to 7.5µs. Without external circuit elements the rise time at the output socket (21) amounts to 0.15µs at 90% of the pulse height, the fall time 0.3µs at 10% of the pulse height, respectively ( see section 3.6 ). At the output socket (32) at the rear panel of the device the pulse can be drawn before the real internal resistance R4 ( 1kOhm ). The rise time amounts to 10ns at 90% of the pulse height. Please pay attention to the following: Caution: At the socket at the rear of the device the output pulse is available before the impedance 1kOhm ( R4 in the schematic chapter 3.7 ); therefore without internal current limiting! This output is intended for the use of an external, high voltageproof limiting resistor. Its value can differ from 1kOhm. This output is not shortcircuit-proof. By means of an external protective circuit you have to safeguard that the pulse current does not exceed 5A! Overload ( I> 5A ) could damage the device! Generally, rise and fall time are changed through external loading. An internal, lowcapacitance 20mH reactance coil can be used to reduce the influence of the capacity of the lamp circuit, especially of the ballast, to the wave form (see section 3.6, fig. 13). From the lamp supply voltage connected to the socket (25) SUPPLY a DC-voltage ( by means of D5, C2 and R6 in the schematic chapter 3.7 ) is generated internally that corresponds to the peak value of the lamp supply voltage. This DC-voltage together with diode D2 makes sure that no current flows parallel to the lamp via the ignition circuit ( on the way via internal resistor R1 and bleed resistor R5 ). Therefore, an obstruction of the take-over can be avoided. Take-over means the maintenance of the electrical conductivity of the plasma in the lamp after the actual ignition pulse by means of the gradual increasing current ( from zero ) of the ballast. Spitzenberger + Spies GmbH & Co. KG Page 3

4 In the same way, the lamp supply voltage is converted internally to a negative DC voltage (by means of D10, C10 and R11 in the schematic diagram, section 3.7) which corresponds to the negative peak value of the lamp supply voltage. Together with the diode D11 this DC voltage avoids the rise of negative overswing. The capacitor bank is charged via a 5kV-DC-voltage-source. Its voltage can be adjusted with controller (17). At least however, the capacitor bank is charged via the free-wheeling diode in the high voltage switch HTS 51 to the positive peak value of the lamp supply voltage, provided that it is connected to socket (25). The release of the ignition pulses happens synchronous to the lamp supply voltage or the mains voltage; the phase angle can be adjusted from 0 up to 180. The triggering can be referred to the positive, the negative or to both zero crossings. In the operation mode CONT a ignition pulse is generated in each sine wave and/or sine half wave. In the operation mode EXT the triggering can be released by means of external pulses. In the operation mode SINGLE both a single pulse ( + or - ) and a double pulse ( +- ) can be released. By means of the function GATE ( gate-time ) internal or external trigger signals can be allowed only during a defined gate time ( adjustable form 1s up to 99s ). The arithmetic average value of the high voltage at the capacitor bank as well as the arithmetical average value of the pulse current ( integral via pulse duration and dead time ) are displayed by built-in digital instruments. For the monitoring of the time characteristics of pulse voltage and pulse current, monitor outputs are available. An oscilloscope trigger signal is output synchronous to the ignition pulse. Spitzenberger + Spies GmbH & Co. KG Page 4

5 3.1. Components and Connections of the Front Panel (Fig. 1) (Fig.1) Pos. Lettering Component Function 1 MAINS switch switching on/off of the instrument 2 T1A miniature fuse T1A mains fuse 3 SOURCE rotary switch synchronization source selection 4 HALF-CYLE rotary switch selection of the sine half-wave within to be triggered 5 PHASE ANGLE coding switch phase angle adjustment ON/OFF switch / LED trigger on/off 7 LED yellow indication of trigger signal available 8 TRIGGER rotary switch trigger source selection 9 SINGLE push-button single triggering 10 EXT. TRIGGER external trigger input 11 ON/OFF tumbler switch gate-function 12 GATE coding switch gate time START push-button start gate time 14 PULSE WIDTH 10-turn potentiometer adjustment pulse width µs 15 CURRENT [µa] digital instrument current measurement (time-averaged) 16 VOLTAGE [KV] digital instrument voltage measurement at the capacitor bank KV 10-turn potentiometer high voltage adjustment 0-5kV 18 SCOPE TRIGGER BNC socket output for oscilloscope trigger 19 MONITOR U BNC socket voltage measurement at the socket (22) 1: MONITOR I BNC socket current measurement 10A/V; shunt between socket 23 and HIGH VOLTAGE high-voltage socket output ignition pulse via real internal resistor 1kΩ Spitzenberger + Spies GmbH & Co. KG Page 5

6 Pos. Lettering Component Function 22 > 100V LED (red) indication: pulse at socket 21 contents a rising edge > 100V 23 LOW safety lab socket feedback of the ignition pulse to the current measurement (monitor I) 24 BALLAST safety lab socket connection for an external lamp ballast 25 SUPPLY safety lab socket lamp supply up to 300V rms 26 LED (yellow) indication lamp supply >10V 27 safety lab socket lamp supply (connected to earth when mains plug of the device is connected to a socket-outlet according to the regulations) 28 RF-CHOKE safety lab socket inductance 20mH between socket 24 and 28 (5A rms at maximum) 29 safety lab socket connection for short-circuit jumper between the sockets 28 and 29 Spitzenberger + Spies GmbH & Co. KG Page 6

7 3.2. Connection of the Rear Panel (Fig. 2) (Fig.2) Pos. Lettering Component Function 30 LINE~ Inlet connector for mains supply non-heating apparatus 31 T6.3A Miniature fuse T6.3A Caution: This fuse connects the output socket LOW (23) via the current shunt for the I-monitor (20) with earth potential (please see page 9). When a fuse is damaged the contacts in the fuse socket can take HVpotential and hazardous voltages may appear. Before unscrewing the fuse socket switch off the device and disconnect each electrical connection from of the socket LOW (23). 32 HIGH VOLTAGE Safety lab socket HV output pulse Caution: At the socket at the rear side of the device the output pulse is available before the impedance (R4 in the schematic diagram; chapter 3.6), therefore without current limiting. An overload (I> 5A) may damage the device! By means of an external protective circuit you have to safeguard that the pulse current does not exceed 5A! Spitzenberger + Spies GmbH & Co. KG Page 7

8 3.3. Operation Switching-on The Lamp Starting Test Instrument can be switched on and/or off with the mains switch POWER (1). After switching on the signal lamp of the mains switch lights yellow, the indications of the digital instruments light red. Caution: At switching on the device may already be in a state generating high voltage pulses. Therefore we recommend to set the switch (6) in position OFF basically before switching of the device Synchronization and Triggering All kinds of trigger pulses are only permitted when the switch (6) is set into position ON ( main switch ). The synchronization source can be selected by means of the switch SOURCE (3). It can be synchronized to the mains supply voltage of the instrument MAINS or to the lamp supply SUPPLY. The device synchronizes itself automatically within a frequency range from 45Hz up to 65Hz. The phase position of the pulse will be determined in angular degrees by means of the coding switch PHASE ANGLE (5). When adjusting more than 180 an internal trigger signal will not be generated. The phase position refers to the zero crossing of the preceding sine half-wave which is pre-selected via the switch HALF-CYCLE (4). The positive ( + ), the negative ( - ) or both sine half-waves ( +- ) can be selected. At synchronization out of the source MAINS it will be synchronized internally to the operating voltage and therefore on the accidental polarity of the mains plug in the socket outlet. During operation mode CONT ( continuous ) at the switch TRIGGER (8) a starting pulse will be released at each synchronization point achieved. If the switch TRIGGER is set into SINGLE position a single pulse ( + or - ) and a double pulse, respectively, ( + and - ) can be started at the phase position adjusted when pushing the button SINGLE (9). For the release of ignition pulses by means of an external signal the switch TRIGGER must be put into EXT position. Now, the start of the ignition pulse can be executed by a rising edge of a TTL pulse at the input EXT. TRIGGER (10). The triggering can be switched on and/or off with the tumbler switch (6). The yellow LED (7) lights continuously at continuous triggering. At single triggering it lights approximately for 0.1s. In order to admit starting pulses for a certain period of time ( gate time ) the switches (6) and (11) must be put into ON position as well as the rotary switch TRIGGER (8) in position CONT. The gate time will be pre-selected by means of the coding switch GATE (12). When pushing the button START the gate time will be started. Now, starting pulses can be released until the time adjusted has elapsed. Spitzenberger + Spies GmbH & Co. KG Page 8

9 Adjustment of the Starting Pulse The voltage height of the starting pulse will be adjusted with the potentiometer 0 5kV (17). The arithmetic average value of the high voltage at the capacitor bank C1 ( schematic diagram, section 3.7 ) is displayed on the digital instrument VOLTAGE (16). At no-load operation the actual pulse height at the output socket (21) corresponds to the indication at the digital voltmeter (16). With external load the voltage at socket (21) decreases compared with the indication at the digital voltmeter (16) because of the voltage drop at the real internal resistance ( 1kΩ ) of the device. This applies to both continuous and single pulse generation. By switching on the continuous pulse generation, switches (6) and (8), the voltage at the capacitor bank remains stabilized within certain limits but it drops beyond these limits ( see output characteristics, section 3.5 ). In case of generation of single pulses the voltage adjusted at the digital voltmeter (16) is available in full range at the output socket (21) at noload operation. The pulse duration can be adjusted from 0.5µs to 7.5µs via the rotary potentiometer PULSE WIDTH (14). The width can be measured by means of an oscilloscope. There is a TTL pulse available at the BNC socket SCOPE TRIGGER (18) which is synchronous to the starting pulse. The pulse current is shown in µa at the display CURRENT as arithmetical average value ( integral via pulse duration and dead time ). The time-depending voltage and current shape of the ignition pulse can be monitored at the monitor outputs U (19) and I (20) via an oscilloscope. The voltage monitor divides the pulse voltage applied at output socket (21) at a ratio of 1000:1 ( 1V at monitor output corresponds to 1000V at the socket 21 ). The current monitor is an internal 0.1Ω-resistor between the sockets (23) and (27) ( 1V at the monitor output 20 corresponds to 10A between socket 23 and 27 ). The red LED (22) lights when the pulse at socket (21) HIGH VOLTAGE contains a fast, positive rising edge >100V. The low-frequency component of the lamp supply voltage, provided that it is applied on socket (21), is not indicated. The yellow LED (26) lights when a voltage >10V rms is applied to the input SUPPLY (25). Spitzenberger + Spies GmbH & Co. KG Page 9

10 Connection of an EUT The ignition pulse is available at the socket HIGH VOLTAGE (21). The lamp can be connected to both this output and the socket LOW (23). The lamp supply voltage will be applied to the sockets (25) SUPPLY and (27) ( internally connected to earth potential ). An isolating transformer has to be applied for the lamp supply. The lamp ballast has to be connected to socket BALLAST (28). The sockets RF CHOKE (28) and (29) are short circuited by means of a shorting jumper. The voltage connected to the socket SUPPLY (25) is used as synchronization source when the switch (3) is set to SUPPLY. The input of socket SUPPLY (25) is protected internally against overvoltages >0.6kV. However, a disconnection of the lamp circuit should not happen in a way that the socket SUPPLY (25) remains connected to the mains-side connection of the ballast ( in this case high voltages may appear at the ballast and applied to socket (25) ) but in the way shown in the circuit diagram on the following page. If the lamp supply voltage is not connected to socket SUPPLY (25) and the lamp voltage is present at socket (21) a direct current of up to 4mA ( according to the lamp supply voltage ) flows into the device. This direct current is indicated at the digital instrument (15) with negative values ( if more than 2mA overflow results ). This can be an indication for the lack of voltage at socket (25). Capacities to ground by connections at the socket (21) increase the rise- and fall time of the pulses. The internal low-capacitance 20mH reactance coil is useful for decreasing the pulse distortion caused by the external ballast ( connected to socket (24) ). At a pulse voltage of e.g. 5kV this inductivity runs into saturation from pulse widths greater than 2.8µs. This causes degradation in the characteristic of the pulse top. During operation the reactance coil can cause a clearly audible acoustic noise. Spitzenberger + Spies GmbH & Co. KG Page 10

11 3.4. Technical Data Ignition pulse Voltage: kV; at least, however, the positive peak value of the supply voltage at socket (29) Internal resistance: R=1kΩ, real, at socket (21) about 0Ω at socket (32) - Caution! - Pulse width: 0.5µs µs, measured with oscilloscope between the begin of the switching edges, see chapter 3.6 Rise time: 0.15µs at 90% of the pulse height at socket (21), without external circuit elements; see chapter ns at 90% of the pulse height at socket (32), without external circuit elements Fall time: 0.3µs at 10% of the pulse height at socket (21), without external circuit elements; see chapter µs at 10% of the pulse height at socket (32), without external circuit elements Stabilization: The voltage of the capacitor bank decreases at switching-on of the continuous generation of a 5kV/2µs pulse each in the positive and in the negative half-wave of a 50Hz synchronization source by at most 300V; further data see characteristics chapter 3.5 Synchronization Synchronization source: optionally mains or lamp supply ( 45Hz 65Hz ) ( lamp supply voltage has to be 10V rms at least ) Phase position: Synchronization edge: positive, negative, or positive and negative zero crossing Spitzenberger + Spies GmbH & Co. KG Page 11

12 Triggering Continuous triggering: Single triggering: External triggering: Trigger input: Gate function: Gate time: Start: End: Scope Trigger: at phase position adjusted in each pos. or neg. sine half wave or in each pos. and neg. sine half-wave at adjusted phase position via external trigger signal TTL; rising edge triggering only during running gate time 1s... 99s push-button (13) starts the gate time gate time elapsed or button (6) in off -position TTL; synchronously to the ignition pulse Display and monitor Voltage display: Current display: 3-digit; arithmetical average value voltage in kv at the capacitor C1 ( 100nF/6kV ) measuring accuracy: <5% 3½-digit; current in µa; arithmetical average value (integral over pulse duration and dead time) measuring accuracy <5% U-monitor: 1V corresponds to 1000V at socket (21) source resistor approx. 0Ω; measuring accuracy: <5% I-monitor: 1V corresponds to 10A between sockets (23) and (27) source resistor 50Ω; measuring accuracy: <5% for oscilloscope input: 1MΩ Power supply: 230V (+6% -10%) 50Hz 60Hz Ambient temperature: 0 C to 40 C Housing: Weight: 19"-desk-top casing (3U) approx. H=170mm,W=540mm, D=350mm approx. 15kg Spitzenberger + Spies GmbH & Co. KG Page 12

13 3.5. Output Characteristics (Fig. 3 8) Output Characteristics means the relation between the voltage of the capacitor bank ( indicated by the digital voltmeter (16) ) and the pulse duration ( adjusted at the potentiometer (14) ). This relation is shown for different external load resistors and synchronization frequencies. For single pulse generation the full no-load voltage is available at all capacitor bank voltages and pulse duration. If a load is connected, the voltage at output (21) is reduced by the series connection of the real internal resistance of the device ( 1kOhm ) with the consumer ( see the diagrams in section 3.6 ). For the continuous pulse generation the voltage of the internal capacitor bank is stabilized in a way that it is independent from the loading by an external consumer within certain limits. Beyond these limits the switching-on of the continuous pulses by switch (6) causes a reduction of the voltage at the capacitor bank. This is displayed at the digital voltmeter (16). The limits of the stabilization are described in the following by the output characteristics 1 to 6: For the output characteristics 1 and 2 ( measured without load ) the voltage at the capacitor bank ( digital voltmeter 16 ) is adjusted first at switched-off pulse to the values 2kV, 3kV, 4kV, 5kV ( characteristic 1 ) and 5kV ( characteristic 2 ). Then, ( by setting switch 6 to position on ) continuous pulses are generated in the positive half wave ( characteristic 1 ) or the positive and negative half-wave ( characteristic 2 ). For this, the pulse width is changed by means of the potentiometer (14), at unchanged voltage potentiometer (17), and the voltage is read at the digital voltmeter (16). The oscilloscope connected to the output shows the same values as the digital voltmeter (16). This voltage drops if the pulse width exceeds a certain value. This indicates that the stabilization of the voltage of the capacitor bank no longer balances the charge loss caused by the internal circuitry even without external load. As characteristic 2 indicates, the stabilization is dimensioned so that for 5kV pulse triggered in both half-waves ( +- ) of a 50Hz-synchronisation source without load at sockets (21) and (29) a pulse duration of up to 2µs is possible with a reduction of 300V at maximum of the voltage of the capacitor bank. At 60Hz this pulse duration decreases to about 1.7µs. Spitzenberger + Spies GmbH & Co. KG Page 13

14 1. Half cycle: + ; without load ( 50Hz ) 2. Half cycle: +-; without load Fig. 3 Fig. 4 5kV 5kV 4kV 4kV 3kV 3kV 50Hz 2kV 2kV 60Hz 1kV 1kV 0kV pulse duration [µs] 0kV pulse duration [µs] For characteristics 3 and 4 the output is loaded with 1kΩ. This value is equal to the internal resistance of the device. As a result, the voltage values at output 21 ( measured with oscilloscope and here not represented ) drop to half of the respective values of the digital indication 16 ( see section 3.6 ). The other adjustments are as for characteristics 1 and 2. By the additional external load the knee in the characteristics 3 and 4 shifts to smaller pulse duration compared to the characteristics 1 and Half cycle: + ; 1kΩ load ( 50Hz ) 4. Half cycle: +- ; 1kΩ load Fig. 5 Fig. 6 5kV 5kV 4kV 4kV 3kV 3kV 2kV 1kV 2kV 1kV 60 Hz 50 Hz 0kV pulse duration [µs] 0kV pulse duration [µs] Spitzenberger + Spies GmbH & Co. KG Page 14

15 For the output characteristics 5 and 6 the output is short-circuited. The output voltage is 0V. Apart from that, the measurement conditions correspond to those of the characteristics 1 and 2. The knee in the output characteristics is shifted to even smaller pulse duration. 5. Half cycle: + ; short circuit ( 50 Hz ) 6. Half cycle: +- ; short circuit Fig. 7 Fig. 8 5kV 5kV 4kV 4kV 3kV 3kV 2kV 2kV 1kV 1kV 60 Hz 50 Hz 0kV pulse duration [µs] 0kV pulse duration [µs] In the approximately horizontal part of a characteristic the continuous pulse generation can be switched on by means of the switch (6) or the gate function without essentially changing the voltage at the digital voltmeter (16). If the parameters pulse duration and no-load voltage of the capacitor bank are selected in a way that they are positioned in the decreasing part of a corresponding characteristic, the indication at the digital voltmeter (16) decreases after 2 to 50 pulses to the value of the corresponding characteristic when switching on the continuous pulse generation (switch (6) or gate function). This has to be considered for measurements. Spitzenberger + Spies GmbH & Co. KG Page 15

16 3.6. Pulse Shape (Fig. 9 14) 1. Single pulses with duration 0.5, 2, 7.5µs Indication 5kV at digital voltmeter (16) oscilloscope at socket (21); no further connections at socket (21) and (29) Fig. 9 0 Pulse height (1kV/div.) Pulse duration (500ns/div.) Fig Pulse height (1kV/div.) Pulse duration (500ns/div.) Fig Pulse height (1kV/div.) Pulse duration (1µs/div.) Spitzenberger + Spies GmbH & Co. KG Page 16

17 2. Single pulse without and with load 1 kω Indication 5kV at digital voltmeter (16); oscilloscope at socket (21); connection of the 1 kω resistor between socket (21) and (23); no further connections at socket (21) and (29) Fig. 12 without load 0 1kΩ load Pulse height (1kV/div.) Pulse duration (250ns/div.) 3. Single pulse without and with load by means of HF-reactance coil 20mH Indication 5kV at digital voltmeter (16); oscilloscope at BNC-socket (20); socket (21) and (23) bridged; no further connections at the sockets; Fig Pulse height (1A/div.) Pulse duration (250ns/div.) Spitzenberger + Spies GmbH & Co. KG Page 17

18 4. Single pulse without and with load by means of HF-reactance coil 20mH Indication 5kV at digital voltmeter (16); oscilloscope at socket (21); socket (28) and (29) bridged; no load: no further connections at the sockets; with load by means of internal HF-reactance coil 20mH: socket (24) and (27) bridged Fig. 14 without coil 0 With coil Pulse height (1kV/div.) Pulse duration (1µs/div.) Spitzenberger + Spies GmbH & Co. KG Page 18

19 3.7. Schematic Diagram (Fig. 15) Fig V rd +HV (Rear Panel) ~LINE CAUTION! N PE L HIGH VOLTAGE C1 9 * 100nF/2000V= HVin D6 S1 HVout (Rear Panel) D1 BY509 R4 4* 1kOhm / 2W (Rear Panel) 31 T 6.3A (Fuse Socket) F1 6.3A R1 R1a R kv 0V bl sw 0...5kV= max.1ma R3 3*33MOhm +5V C3 10nF C4 2µ2 High Voltage Switch HTS 51 gnd TTL R7 1kOhm R5 3* 330Ohm 2W D2 UF4005 R6 C kOhm 10µF 450V D5 UF4005 D10 UF C10 10µF 450V D11 BY 509 R11 100kOhm R8 4 * 100 Ohm C5 10µF C6 100 nf + +5V 5.00 kv Digital Display µa MONITOR U Digital Display U 0-330V~ T1 20mH internal D7 BY509 R9 0.1 Ohm 9 U 0-33V~ T2 2 C7 18nF/450V R10 50 Ohm Controlling and Triggering D8 2* 1.5KE300CA (Front Panel) SCOPE TRIGGER BALLAST SUPPLY I U MONITOR LOW RF CHOKE HIGH VOLT T3 BALLAST External Circuit S2 LAMP ON/OFF V1 LAMP Mains T4 T5 do not disconnect U 0-300V~ ISOLATION TRANSFORMER Spitzenberger + Spies GmbH & Co. KG Page 19