BNC PCO-6131 Operating Manual Download Page 19

Berkeley Nucleonics Corporation    

 

2955 Kerner Blvd., San Rafael, CA 94901 °  Tel (415) 453 9955   °   Fax (415) 453 9956   °   www.berkeleynucleonics.com 

 

 

Figure 12 - 5 Microsecond Pulse Width – Wire Interconnection 

4.3 Microsecond Fall Time, 454 ns Rise Time 

As can be seen from the data above, even the inductance of 6 inches of wire in 

the connection between the stripline and the laser diode can result in a 5X to 8X 

degradation in the rise time and fall time.  

7.0  Troubleshooting 

WARNING 

The module contains capacitors that are used as energy storage elements. When 

charged, these capacitors contain more than 7 joules of stored energy. This is 

enough energy to cause injury. Assure that the +24 VDC power is disconnected 

from the pulser, and that the capacitor bank is fully discharged before any repairs 

or adjustments are attempted. Verify with a voltmeter that all circuits are de-

energized before servicing. Dangerous voltages, floating ground planes and 

energy storage exist at several locations in the module. Touching connections or 

components could result in serious injury. 

 

 

Summary of Contents for PCO-6131

Page 1: ...PCO 6131 Laser Diode Driver Module Operating Manual...

Page 2: ...Berkeley Nucleonics Corporation 2955 Kerner Blvd San Rafael CA 94901 Tel 415 453 9955 Fax 415 453 9956 ww berkeleynucleonics com...

Page 3: ...uctions 5 5 1 Output Stripline 5 5 2 Load Interconnection 5 5 3 Gate Input 6 5 4 Enable Input 6 5 5 Output Current Setpoint Monitor 6 5 6 Internal and External Current Setpoint 7 5 7 Leading Edge Rise...

Page 4: ...e these precautions can result in potential electric shock to personnel arcing and damage to the connectors and system 4 The Laser Diode Driver contains reference planes which are elevated to the pote...

Page 5: ...age applied to the inductor is 24 Volts This results in a very fast increase in current so very short on times are necessary When the controller switches off then a very small voltage is across the in...

Page 6: ...f the pulse The rise time may be slowed down using the variable rise time control to minimize or eliminate this ringing 3 0 System Requirements The PCO 6131 requires user supplied 24 VDC support power...

Page 7: ...rolled The output pulse current may be monitor using the optional external current monitor board PCA 9155 via the cable Scaling is 1000 A V into 50 Ohms The output of this CVR has a 51 1 Ohms resistor...

Page 8: ...t may also be set by a remote analog input See Section 5 0 for more details The variable rise time is adjusted by the Rise Time potentiometer located on the edge of the smaller logic circuit board All...

Page 9: ...g via transients and therefore when the pulse generator is turned on or high voltage is present in the chassis assume it is possible to get a pulse on the output connector 5 1 Output Stripline The PCO...

Page 10: ...y any high quality low voltage pulse generator The gate signal should be connected to J2 8 using a 50 coaxial cable The shield of the coaxial cable should be connected to any one of the ground pins of...

Page 11: ...10 V Then slowly adjust the current setpoint potentiometer until the desired output current is obtained on the Output Set Point Monitor DO NOT OPERATE OR PULSE THE UNIT INTO AN OPEN OR HIGH IMPEDANCE...

Page 12: ...ted if it does not vary below 20 V or above 28 V At 125 A output the driver dissipates 75 W when enabled but not pulsing Efficiency is therefore the ratio of output power to the input power or output...

Page 13: ...using the Output Current Setpoint Monitor and the procedure detailed in steps 8 11 above turn the Current Set potentiometer fully counterclockwise to set the output current to zero 13 Enable the PCO...

Page 14: ...integral to obtaining good fidelity of current pulses The strip line shown in the figures in this note is the stripline supplied with the PCO 6131 and is available from BNC When a stripline is used a...

Page 15: ...Test Setup Figure 4 and 5 show how the output stripline was connected to the laser diode for the first set of tests In Figure 4 the stripline was intentionally separated to show connections Normally i...

Page 16: ...tion to Laser Diode Using this interconnection at 50 A output the following electrical performance was measured For all photos the top trace is the input gate to the PCO 6131 and the bottom trace is t...

Page 17: ...Time Using a Stripline Figure 8 10 Microsecond Pulse Width 550 ns Fall Time 67 ns Rise Time Using a Stripline We then connected the laser diode to the PCO 6131 output stripline using approximately 6...

Page 18: ...imately 6 Inches of Wire Using this interconnection at 50 A output the following electrical performance was measured For all photos the top trace is the input gate to the PCO 6131 and the bottom trace...

Page 19: ...fall time 7 0 Troubleshooting WARNING The module contains capacitors that are used as energy storage elements When charged these capacitors contain more than 7 joules of stored energy This is enough e...

Page 20: ...e voltage too low Input gate pulse width too short Increase width Input gate frequency too high Reduce frequency No 24 VDC input voltage Check input supply and connections Enable circuit not satisfied...

Page 21: ...y changes in the design or construction of its products at any time without incurring any obligation to make any change whatever in units previously delivered BNC s sole obligation and buyer s sole re...

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