| | 1 | Up to [[Laser_PC_Board_Designs]] |
| | 2 | |
| | 3 | Assembly changes: |
| | 4 | |
| | 5 | * Remove R5, R6 |
| | 6 | * R105, R118, R131, R144 - change from 10.0k to 35k (+/-10% ok) |
| | 7 | * Install wire jumpers from pins 2-3 of JP2-JP9 (8 places). |
| | 8 | * Install wire jumper across JP1 |
| | 9 | |
| | 10 | Proposed PCB ECOs: |
| | 11 | |
| | 12 | * Add test point for current limit set (R47 etc). |
| | 13 | * (Add photodiode readout) |
| | 14 | * Add hardware "laser on" indication |
| | 15 | * Add low-pass filter on temp sensor inputs |
| | 16 | |
| | 17 | Notes: |
| | 18 | |
| | 19 | Resistor values R105,107,108 set temperature window. Default values won''t work. |
| | 20 | Details depend on thermistor but a good start would be to change them as follows |
| | 21 | for a modest range around 25 deg C: |
| | 22 | |
| | 23 | Pot R47 sets current limit for laser shutdown. |
| | 24 | |
| | 25 | Laser won''t turn on unless the following are true: |
| | 26 | |
| | 27 | {{{ |
| | 28 | I_SHUTDOWN - backplane INTERLOCK must be at 0V (needs connector or resistor if no system controller) |
| | 29 | EN0/1/2/3 - must be logic ''1' from backplane (pull-down 10k on Laser/TEC) |
| | 30 | L_SHDN - uC output PD7 must be ''0' |
| | 31 | |
| | 32 | }}} |
| | 33 | |
