2017-05-18 17:07:07 +08:00
Hardware errata
===============
Rev 1
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* 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
2017-05-31 13:06:24 +08:00
* R214 -> 7.5k
2017-05-18 17:07:07 +08:00
* 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
2017-09-20 19:57:19 +08:00
* C500 -> 1nF
2017-05-18 17:07:07 +08:00
* R234 -> 7.5k
* Q104 -> DMN3404
* R114 -> 470 ohm
* R115 -> 4.7k
* R227 -> 470 ohm
* R228 -> 4.7k
* review values of R226 and R113
2017-09-20 19:57:19 +08:00
* C100 -> 47pF NP0 AVX, R107 -> 100K, C101 -> 0.1uF
2017-05-18 17:07:07 +08:00
* use crystal type recommended by the MCU datasheet
* add connector for OLED display?
2017-07-05 00:39:27 +08:00
* enlarge holes to fit M3 screws comfortably
2017-12-29 15:05:12 +08:00
* add 15M resistor between A and FIL-
2017-07-05 00:39:27 +08:00
* power U200 from a small negative voltage instead of GND
2017-07-31 13:27:57 +08:00
* review choice of filament flyback output diode
2017-08-07 16:36:21 +08:00
* invert LED position so that the Ethernet LED is closest to the connector
* invert polarity of LEDs (Ethernet LED polarity cannot be programmed)
2017-09-28 17:30:28 +08:00
* change D351 model to MBR1645
* add snubber on D351
* add heatsink (Seifert-KK633) to D351
2017-12-29 15:05:12 +08:00
* 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
2018-02-11 20:30:25 +08:00
* 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.
2018-02-13 18:26:13 +08:00
* 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
2018-04-14 18:29:55 +08:00
* add 12V fan connector and on/off circuit (with optocoupler)
* increase sencitivity to ~20fA / LSB
