49 lines
2.0 KiB
Markdown
49 lines
2.0 KiB
Markdown
Hardware errata
|
|
===============
|
|
|
|
Rev 1
|
|
-----
|
|
|
|
* R307 needs more clearance from D400
|
|
* Pins 1 and 12 of U502 need pull-downs
|
|
* Pin 1 of U501 needs pull-up
|
|
* D203 reversed polarity
|
|
* R236 and R234 are swapped
|
|
* Q301 needs to be NPN, change to BC817
|
|
* increase R307 -> 3.3Kohm and increase R500 -> 33Kohm
|
|
* C201: oscillates at 0 and 1nF, stable at 100nF
|
|
* add clamp diodes to GND on op-amp outputs to ADC when op-amp has negative supply
|
|
* R214 -> 7.5k
|
|
* LM339PT is in TSSOP package. Change for SOIC P/N
|
|
* GDT200 minimum firing voltage is too low
|
|
* the relay model should be changed to 9001-05-00. 9001-05-02 is an undocumented normally closed variant.
|
|
* D504 should follow the schematics in its datasheet
|
|
* R502 should be connected to VCC
|
|
* R502 -> 240 ohm
|
|
* C500 -> 1nF
|
|
* R234 -> 7.5k
|
|
* Q104 -> DMN3404
|
|
* R114 -> 470 ohm
|
|
* R115 -> 4.7k
|
|
* R227 -> 470 ohm
|
|
* R228 -> 4.7k
|
|
* review values of R226 and R113
|
|
* C100 -> 47pF NP0 AVX, R107 -> 100K, C101 -> 0.1uF
|
|
* use crystal type recommended by the MCU datasheet
|
|
* add connector for OLED display?
|
|
* enlarge holes to fit M3 screws comfortably
|
|
* add 15M resistor between A and FIL-
|
|
* power U200 from a small negative voltage instead of GND
|
|
* review choice of filament flyback output diode
|
|
* invert LED position so that the Ethernet LED is closest to the connector
|
|
* invert polarity of LEDs (Ethernet LED polarity cannot be programmed)
|
|
* change D351 model to MBR1645
|
|
* add snubber on D351
|
|
* add heatsink (Seifert-KK633) to D351
|
|
* move D351 further away from transformer for heatsink clearance
|
|
* add plated-through holes and pads for mounting rods of BNC connector
|
|
* simplify FBI circuit, 2 ranges only (typ. 8mA and 45mA), remove diodes and neglect MOSFET leakage
|
|
* to support different case designs, replace the holes on the connectors side with slots. One of the case designs requires holes whose center is at 11.5mm from the board edge.
|
|
* review choice of external LED connector type and clearance
|
|
* if using a non-polarized connector, change pinout so that connecting the LEDs the wrong way cannot cause damage
|