IOO (Laser Bench)stefan.ballmer - 22:03 Tuesday 12 June 2018 (5254)
Print this reportPMC Slow Path fixedChanges / fixes implemented:
- On D0901895, TTFSS SLOW (S1503974, modified TTFSS): R4 to 8.2kOhm. This makes a 1/2 voltage divider, which is needed, since the slow signal coming in is 20Vpkk on each lead, differential, i.e. 40Vpkk total. This needs to fit in 20Vpkk putput range.
- Replaced the AD620BR opamp - the old one was broken, which is why we never got any good signal out.
- Added 47nF and 51kOhm in parallel to C5. This is the ground reference for the AD620 output in case no other ground is connected.
- Isolated both TNC outputs (FAST and EOM) from chassis ground using isolation tape.
With there modifications I believe the board is ready to be able to remote-control the PMC locking - we will try tomorrow.
Other possible changes that are not implemented yet:
We do not need the AO input. Pulling R5 on D040105 (TTFSS Common Path) This would free up the AO enable remote control. We could use that line to remote-control the fast path EXC enable. The easiest way to do that is connecting PINS 19 and 21 (AOE and T3E) on P1 of D040105 (TTFSS: Common Path).
Comments to this report:
stefan.ballmer - 17:35 Wednesday 13 June 2018 (5266)
Print this reportWe installed the PMC servo electronics today. The output offset control through the slow channel works as advertised. We made some basic modifications to the PMC medm screen to make it easy to hand-lock. The model and guardian will be updated tomorrow.