Introduction to VME64 high voltage modules
VME64 / VME64x standard:
The VME64 high voltage modules ” Versa Module Eurocard ” are a high speed bus with an efficient interruption management system based on a multiprocessor architecture. The 64-bit bus provides a high transfer rate of 80 MB/s with 32 address lines and 32 multiplex data lines.
The VME64x bus represents an extension of the VME64. The major contribution relates to the extension of the 5-row connectors of 160 pins P1 / J1 and P2 / J2 and of additional connectors of 95 pins P0 / J0. This increases the number of user defined inputs / outputs. The bandwidth is increased to 160 MB / s. In addition to the + 5 V and +/- 12 V supplies for the VME64, the VME64x uses additional supplies, the + 3.3 V and the + 48 V. The “live ” insertion of the modules via insertion / extraction latches is possible. Also the IEEE 1101.10 standard has contributed to better electromagnetic compatibility (EMC) and better tolerance to electrostatic discharge (ESD) via contact clips.
Mechanics of the VME64 and VME64x high voltage modules:
The mechanics of the VME modules are based on the Eurocard 6U format with a depth of 160 mm. The modules are equipped with two J1 and J2 connectors of 3 rows DIN-96 (the VME64x has 5 rows DIN-160) corresponding respectively to the backplane connectors P1 and P2.
A complete range of high voltage modules:
We offer a wide range of VME64 high voltage modules in different configurations:
- standard and high precision with 2 channels, they are adjustable in local mode via a complete instrumentation, and their polarity is reversible (+) and (-). They exist in the following versions: 2 kV, 3 kV, 4 kV and 5 kV.
- multi-channel concept, available in 2, 4 and 12 channels, from 500 V to 20 kV. Each of the channels has voltage and current regulation.
- distributor with a multi-output concept, from 8 to 24 channels and from 500 V to 3 kV. It offers the ‘live insertion / live extraction’ function, which allows to connect and disconnect the module in its chassis while it is
VME64x High voltage modules Standard and High Precision VHQ
The modules are available in 2 versions, Standard and High Precision. They have 2 output channels, and voltages from 2 kV to 5 kV for currents from 1 mA to 6 mA. A special version offers currents which are doubled.
Instrumentation of the VME64 and VME64x high voltage modules:
These modules have full instrumentation on the front panel. There are several configuration switches. On / off, KillEnable / KillDisable, current monitoring / voltage monitoring, local / remote mode selection, channel A / channel B selection. A precise 10-turn potentiometer for voltage adjustment and a 4-digit LCD liquid crystal display. The measuring of voltage and current is done by mantissa + exponent. There are also 2 rotary micro switches with a 10% increment hardware clamp restraining the voltage and the current.
Switchable polarities from the outside:
The polarities are switched by a rotary switch placed on the lateral panel, in the center, and accessible from the outside. It is not necessary here to remove screws, open the cover and turn the high voltage block to change the polarity. There is no risk of breaking pins or tearing off components during such an operation.
The VME64 and VME64x VHQ high voltage modules are controlled via the VME bus of a VME64 / VME64x chassis.
This concept has been proven for almost 20 years. It has been continuously upgraded with the latest technologies. VHQ modules are used in many applications in nuclear and particle physics, at the CNRS, in the IN2P3 and at the CEA (French Atomic Agency).
The VHQ standard module is available with voltages of 2 kV, 3 kV, 4 kV and 5 kV for powers of 6 W. A HCU ‘high current’ version offers powers up to 12 W.
The VHQ high precision module is available in 8 versions from 2 kV to 5 kV and from 1 mA to 6 mA. It uses the known performances of the standard model. It has a current measurement loop to which a second measurement loop has been added; its threshold can either be 65 µA (option 2MA) or 6.5 µA (option 2MA0n1).
VME64 high voltage modules Standard VHS
VME64 multi-channel high voltage modules:
The cassettes VME64 and VME64x of the VHS STANDARD series can have up to 12 independent channels. They each have 2 regulation loops, for voltage as well as current. In addition to a voltage setpoint, a current setpoint is defined. It is labeled in an “Ilim” case to limit and regulate current or “Itrip” to cause the channel to trip when the current delivered (measured) has reached the setpoint. To do this, a Kill Enable / Kill Disable function allows you to switch from one mode to another.
Patented technology and unrivaled precision:
The VHS model has patented resonance switching technology. It is associated with unique high-voltage ceramic dividers with very low drift and with 20-bit DAC and 24-bit ADC converters. These are placed as close as possible to the HV stages and to the central processor, thus conferring a level of resolution of 2.10 (-6) * Vnominal and an unequaled precision levelwith a very small deviation (standard deviation) defined by the relation + / – (0.01% Vout + 0.02% Vnominal). The STANDARD module is suitable for large installations such as CERN or GANIL.
The VHS CG (common ground) module exists in 3 versions of 2 channels, in 6 versions of 4 channels and 6 versions of 12 channels, from 500 V to 20 kV and from 400 µA to 15 mA. Theground of the module is connected to the ground of the chassis.
VME64 High voltage modules Distributor VHS
Distributor module with single step-up transformer:
The VME64 and VME64x DISTRIBUTOR modules are designed based on a simple idea. The concept was to offer the largest number of channels in the most confined spaces with the lowest possible cost per channel ratio. This objective has been achieved with the VDS series which is available in either 8 or 24 channels, in the width of 1 to 2 slots! The VDS cassette does not have current regulation, but it has current protection. It has the effect of a disjunction in case the limit has been reached.
Hot insertion / extraction function:
A specific feature of the VDS relates to the ‘live insertion / live extraction’ function. It allows to insert and extract the hot module from its chassis. The resolution level, for voltage as well as for current, is 1.10 (-5) Vnominal. Its precision level remains within an error interval of +/- (0.01% Vout + 0.02% Vnominal). The high channel density is made possible thanks to the multi-pin Redel connectors. The VDS model is great for supplying an infinitely high number of photomultiplier tubes where there is no requirement for adjusting their gain.