The Models NHQ 202M-206L HV supplies are a two channel high voltage version in a NIM chassis. Modern patented circuit principles in connection with the latest SMT manufacturing technologies permit the design and construction of very compact high voltage supplies with excellent specifications.
All NHQ models are 1 slot wide, and offer either manual control or operation via RS232 Interface. The use of this interface supports more then the manual control functionality.
The high voltage supplies provide high precision output voltages together with very low ripple and noise, even under full load. Separate 10%-step hardware switches enable to set voltage and current limits. An INHIBIT input provides instant shutdown to protect sensitive detector devices.
Additionally, the maximal output current per channel is programmable via the interface. The high voltage outputs protected against overload and short circuit. The output polarity can be selected by manual rotary switches accessable from the side of the module without having to take the side-cover off.
The output voltage can also be set by software through the RS232C interface. The chosen polarity is displayed by a LED on the front panel and a sign on the LCD display. It is not allowed to change the polarity under power! An undefined switch setting (not at one of the end positions) will cause no output voltage.
For effective protection of connected devices the maximum output voltage and current can be selected in 10%-steps with the rotary switches Vmax and Imax (switch dialed to 10 corresponds to 100%). An output voltage or current exceeding the set limit is signalled by the red front panel error LED.
- Dual HV supplies in single NIM packages
- Regulated 0 to + 2kV, 3kV, 4kV, 5kV and 6 kV DC, output current - see table
- lprogrammable HV-ramp 2 .. 255 V/S and 500 V/S ramp hardware settable, up and down
- LCD Display 4 digits with sign for voltage and current.
- Resolution of voltage indication: 1V
- Resolution of current indication: 1uA
- Frontpanel LED indicators for polarity
- Low noise and ripple for high resolution detectors: < 2 mVpp typical, 5mVpp max.
- Settable voltage and current limiting
- Short circuit and overload protected
- Programmable HV parameter setting and polling of actual values via RS232C interface
- Continuous setting of HV over full range with 10 turn Helipot
- Easy access to manual polarity switch
- External input for HV shutdown
Function of the KILL switch:
Switch to the right position: (ENABLE KILL)
The output voltage will be shut off permanently without ramp on exceeding Vmax, Imax or in the presence of an INHIBIT signal (Low=active). Restoring the output voltage is possible after operating the switches HV-ON or KILL or reading “LAM status” and then “Start voltage change” by DAC control.
Note: When capacitance is effective at the HV-output or when the rate of change of output voltage is high (hardware ramp) at high load, then the KILL function will be released by the current charging the condenser. In this case use a small rate of output change (software ramp) or select not until output voltage is set voltage.
Switch to the left position: (DISABLE KILL)
The output voltage will be limited to Vmax, output current to Imax respectively; INHIBIT shuts the output voltage off without ramp, the previous voltage setting will be restored with hard- or software ramp on INHIBIT no longer being present.
Operation under RS232 control
The most important parameters of the high voltage supply can be set and read under computer control via the RS232 interface. An optional VI (virtual instrument) is available for easy setting of parameters by simple mouse click.