LVHV Board¶The Low-Voltage High-Voltage (LVHV) Board is contained in the water proof housing along with the LAPPD. It receives a 12V line and ground, passed from the rack electronics by way of the water proof cables. It's function is:
- To produce 3 different low-voltages, using switching power supplies (3.3V , 2.5V , and 1.2V): These low voltages power the trigger board and the ACDC cards (in place of the original linear regulators, which consume too much power)
- To produce high voltage and divide it down, in order to power the 5 stages of the LAPPD (photocathode, top of entry plate, bottom of entry place, top of exit plate, bottom of exit plate). The maximum voltage will be below 3.5 kV.
- To serve as a slow-controls interface between the various sensors, power circuits, and communications lines. The LVHV talks to the surface electronics through a CANBUS interface and uses a PIC microcontroller.
The schematics for the board can be found here .
The LVHV can be seen in the context of the system diagram found here.