From a8972363adf82e92263507395bb7d73caba41505 Mon Sep 17 00:00:00 2001 From: Rahix Date: Mon, 16 Jun 2025 10:54:12 +0200 Subject: [PATCH] Add a bit more documentation on the electronics. --- Electronics/README.md | 26 +++++++++++++++++++++++++ Electronics/STM-Functional-Overview.png | 3 +++ 2 files changed, 29 insertions(+) create mode 100644 Electronics/README.md create mode 100644 Electronics/STM-Functional-Overview.png diff --git a/Electronics/README.md b/Electronics/README.md new file mode 100644 index 0000000..077445f --- /dev/null +++ b/Electronics/README.md @@ -0,0 +1,26 @@ +## STM Original Electronics +This directory contains the documentation of the original control electronics of the STM. We did some modifications which are detailed below. + +### Overview +![Block diagram of the STM](./STM-Functional-Overview.png) + +The **Control Box** schematic can be found in [`STM_Main_neu_Schaltplan_3.pdf`](./STM_Main_neu_Schaltplan_3.pdf). + +The **Preamplifier** schematic is [`STM_Vorverst_neu_2.pdf`](./STM_Vorverst_neu_2.pdf). + +### Modifications + +- Preamplifier + - *[2025-06-14]* Added a 1nF capacitor parallel to `R10` to mitigate 12kHz + oscillation and stabilize the amplifier. +- Control Box + - *[2025-06-14]* Disconnected `R36` from `R1`/`C1` and instead connected it + to -15V through a separate 10k resistor. This inverts the setpoint + voltage, which was necessary to make the differentiator actually calculate + an error difference. Previously, it was summing the setpoint and control + variable... + - *[2025-06-14]* Cut out `R8`, the resistor parallel to the capacitor of the + integrator (I-controller). This resistor was preventing the integrator + from stably integrating at very low frequencies. + - *[2025-06-15]* Added a 1µF capacitor parallel to `C7`. This mitigates 1.47 + kHz oscillation when the amplifier gain is high. diff --git a/Electronics/STM-Functional-Overview.png b/Electronics/STM-Functional-Overview.png new file mode 100644 index 0000000..861347b --- /dev/null +++ b/Electronics/STM-Functional-Overview.png @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:512fce937a6997beefd3cb4f434574d2350f356f680f2264037ae1a33859e3eb +size 41412