The High-pt system uses KEPCOmodel ATE 6-100M linear power supplies for low voltage power on the front end readout electronics. These supplies are rated at 1000W each and have a DC output range of 0V to 6V and output current from 0 to 100A.The High-pt front end readout electronics use 7 different voltages:
+3.0V Analog VCC for the ASD chips -3.0V Analog VEE for the ASD chips +3.0V Digital VCC for the ASD chips -3.0V Digital VEE for the ASD chips -3.0V VE3 for the ASD chips +5.5V for the DAC chips only
The +X and -X chambers are powered from the same supplies.
The power supplies are manually controlled and monitored at the Low Voltage Control Panel in the High-Pt I/O rack in the e-hut. The panel has a master switch for turning off the output from all the supplies. For each supply there is
- a potentiometer for setting or adjusting the output voltage,
- a potentiometer for setting or adjusting the output current limit,
- test points to measure the voltage and current from the supply,
- a current mode LED, indicating that the output current exceeds the current limit, and
- a switch to disable that supply.
Control of the power supplies is achieved by manipulating the signals (voltage levels) sent over the control cable from the e-hut to the programming connector of the supplies. Below is a list of the signals on the control cable.
output sense (-) programming common preamp A input (-) preamp B input (-) preamp A input (+) preamp B input (+) preamp A output preamp B output external curent comp. ampl. input (-) external current comp. ampl. input (+) voltage comparison input current sensing amplifier output -6.2V reference programming common isolated mode flag (-) isolated mode flag (+) Table 2: A list of the signals on the LV control cables.
In the e-hut, the control cables are connected to the LV power supply control panel.