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Thermostat

2-channel temperature controller.

Design files (schematics, PCB layouts, BOMs) can be found at Thermostat/Releases.

Overview

Channel count: 2
Sensor: 10k NTC thermistors read by AD7172-2 ADC
Load (heater/TEC) drive: up to 8W (+/-2A with 4V compliance) from MAX1968 drivers
Form factor: 3U module or stand-alone enclosure (Hammond 1455C1202)
Output connectors: Sensor and load connect via terminal block connector on the stand-alone enclosure version or via internal 100mil pin-header on the 3U version (can be broken out to a separate front panel with 2xD9, such as Schroff 30849-750).
Programming interface: Ethernet via RJ45 connector on the front panel. USB via micro USB connector on the front panel.
Indicators 4 front panel LEDs
Power supply: +12V DC (1.7A max) supplied either by a front-panel barrel connector, internal 100mils pin-header, or rear Molex connector (3U version only). PoE via onboard 30W Silvertel AG5300 module.
Microprocessor: STM332F427ZI

Firmware

Previous Versions

Thermostat_Thorlabs: Based on a Thorlabs temperature control module. The Thorlabs module has a poor tempco and can't drive resistive heaters so that approach was scrapped in favor of this one (see issue #4).

Thermostat v1: Prototype version based on a different microprocessor