Table of Contents
Voltage controll
We have two power supply units, both controlled by a LabVIEW script via the server. We use a Low Voltage Power Supply Unit (LVPSU), the HMP 2030 by Rohde & Schwarz. The LVPSU powers the LTA with 12 V and 1-2 A and supplies the base power for the CCD. For a High Voltage Power Supply Unit (HVPSU), we use the Keithley 2470 SourceMeter. It is used to deplete the CCD of any free charge, using around 50-70 V. It has very high precision, capable of measuring currents down to femtoamperes. This precision is needed to test for defects in CCDs.
HMP 2030
Current and voltage range of the HMP2030
| Voltage Range | Max Current (A) | Power Management | Voltage Precision | Current Precision | Ripple (Voltage) |
|---|---|---|---|---|---|
| 0 - 16 | 5 | Standard | ±(0.05% of output + 5 mV) | ±(0.1% of output + 5 mA) | < 150 µVrms (typ. 1.5 mVrms) |
| 16 - 32 | 2.5 | Intelligent Power Management | ±(0.05% of output + 5 mV) | ±(0.1% of output + 2 mA) | < 150 µVrms (typ. 1.5 mVrms) |
they feature the following output seetings:
| Channel | Power (V) | Current seetings | Current drawn |
|---|---|---|---|
| HMP 2030 (1) | |||
| 1 | 15 | 0.6 | 188 mA |
| 2 | 15 | 0.6 | 325 mA |
| 3 | 30 | 0.1 | 1.8 mA |
| HMP 2030 (2) | |||
| 1 | 12 | 2 | 1.5 A |
| 2 | 5 | 0.15 | 136 mA |
| 3 | 5 | 0.15 | 136 mA |
* Manual
Kethley 2470
It features two triaxial connectors: one for the high voltage (HV) and one for the return ground, which is floating. As a result, there are six conductors for a two-wire connection. The center conductor of each cable carries the HV and return signals, respectively. The outer conductor of each cable is connected to the chassis ground, which is linked to the outer shell of the metal box protecting the instrument. In addition, an intermediate conductor in each cable applies a potential that shields the central conductor from fluctuations in the external ground. This design allows for a resolution of up to 10 fA [59]. Its characteristics can be found in Table:
| Characteristic | Range | Details |
|---|---|---|
| Voltage Source Range | 200 mV to 1100 V | Maximum sourcing voltage |
| Current Source Range | 10 nA to 1 A | Maximum sourcing current |
| Maximum Output Power | 20 W | Total output capacity |
| Voltage Measurement Accuracy | ±(0.012% + 200 µV) | High precision for voltage measurements |
| Current Measurement Accuracy | ±(0.020% + 15 nA) | High precision for current measurements |
| Resistance Measurement Range | 2 Ω to 200 MΩ | Accurate over a wide range |
| Ripple and Noise (Voltage) | < 1 mVrms | Low ripple voltage for stable sourcing |
| Ripple and Noise (Current) | < 10 µArms | Low current ripple for precise applications |
| Measurement Resolution | Down to 10 fA | Suitable for low-current applications |
VME8004X
The VME crate provied the following outputs:
| Output | Power (V) | max Current (A) | Current usage by 1 ACM |
|---|---|---|---|
| 1 | +3.3 | 25 | 2.4 A |
| 2 | +5 | 25 | 0.18 mA |
| 3 | -12 | 10 | Generated by the ±15 V line |
| 4 | +12 | 10 | |
| User Input -V1 | -15 | Set by HMP2030 | 188 mA |
| User Input +V1 | +15 | 325 mA | |
| User Input -V2 | -30 | 2 mA | |
| User Input +V2 | N/C | ||
To generate this voltages/currents it uses a Elma VME backplane (Article Number: 32220-204-0B60) 4 slot 6 HE VME64x 4 Slots with P0, with M3/M4 power bolts board (Link). I has the following features:
- Characteristic Impedance 55 Ohm +/-10 %
- Effective DC decoupling 1GHz (acts as an EMI-Filter)
- Integrated termination
- daisychain automatically activates
- 4 slots
Grounding
The following picture depicts the grounding of the entire system, for better readability the Lan connections are not shown. These Lan connection also pass the ground from every system to system.
Flowchart
For better understanding on how the different components of the power subsystem are linked together, the following scheme is provided:
