v1.0 HW issues

[gkasprow]

• N1V8 rail  #3
  Let's replace it with LMC7660

[gkasprow]

• use tht connectors only for modules to avoid alignment issues

[gkasprow]

• fix the module HV dc/dc footprint

[gkasprow]

• unify RC footprints

[gkasprow]

• swap R24 with R25 on channel PCB

[gkasprow]

• add 1u cap and change R to 10k

[gkasprow]

add debug LEDs:

• - supply on external sensor
• - HV divider resistor selected

[gkasprow]

• GPIO12 is strapping pin and should be avoided

[gkasprow]

• add rpi connector and mechanical fixing

[gkasprow]

• add 1u cap and change 1k-> 10k at the main board , too

[gkasprow]

• add HV discharge circuit?

[gkasprow]

• fix heavy dc/dc converter both on the mainboard and on the channel board

[gkasprow]

• consider using better 5V reference for DAC instead of ADP7102ARDZ-5.0-R7

[gkasprow]

• Add HV present LED based on divider current measurement

[gkasprow]

• add cutout under wifi antenna on the mainboard

[gkasprow]

• channel numbering from 0

[gkasprow]

• change module HV resistor switch - instead of T15 use another AQV224NS

[gkasprow]

• increase the number of series resistor for drift (HV7). We may expect up to 2kV there

[gkasprow]

• change divider resistors to 2010 - we may get 700V there

[gkasprow]

• Make 4 bit HV resistor setting

[gkasprow]

• add interlock input

[gkasprow]

• Add DIP-switches or jumpers and standard resistors on mainboard

[gkasprow]

• missing R from divout to GND

[gkasprow]

• add HVQC 2x BJT+divider - we need even 2.5kV
• add main pcb fixing holes + spacers

[gkasprow]

• R71=200k

[gkasprow]

• debug LED on each channel

[gkasprow]

• consider using opamp with lower Vos or use higher gain, for the moment we have 0.256V ADC range

[gkasprow]

• add HV locking feature - for the moment HV DC/DC gives max voltage during turning on - BSS138+bat54c+10u+240k

[gkasprow]

• add measurement of the additional divider / emitter follower voltage on the main board instead of 12V U meas

[gkasprow]

• make the adjustment range much smaller. now is 450-590V for channel 0

[gkasprow]

• add 15mm plastic standoffs to the BOM
• add M3 6-8mm countersunk screws to the BOM
• add M3 8 mm Nylon screws to the BOM

[gkasprow]

• add GND terminal!!!

[gkasprow]

• move CH2 away from the enclosure support - the HV may destroy antenna

[gkasprow]

• add M2.5 countersunk screws + nuts to the BOM (Ethernet adapter fixing)
• add rpi4 + SD card to the BOM

[gkasprow]

• add 10nF cap in parallel to BSS127 G-S

[gkasprow]

• add silk frame around CH2 outputs

[gkasprow]

• move R4 on the mainboard to drain

[gkasprow]

• Add ethernet and usbc cables to BOM

[gkasprow]

• Add hammond enclosure to BOM

[gkasprow]

• add interlock input, PG output

[gkasprow]

add HV slew rate control

[gkasprow]

• consider using MCP41HV51T-104E or similar HV digital potentiometer; add LM2733 36V buck. Use generic SPI components + lambdas in ESPHome
• edit: prototype uses MCP41HV31T-104E - a 127 tap version of the one above

[gkasprow]

• rename HV_Imeas to AVD I meas

[gkasprow]

• add DFF to HV EN

[gkasprow]

• remove ref diode;
• reverse Zener diode
• Rg=10k
• add R shunt = 5k6/3

[gkasprow]

• add TVS for drift active divider