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--- projects:laser_cutter:work_logs:1_beginnings [2022/03/31 00:27] – created tjhowse
+++ projects:laser_cutter:work_logs:1_beginnings [2022/03/31 00:51] – tjhowse
@@ Line 12: / Line 12: @@
 Two Aspen chiller units joined in series.
-===== The code =====
+Once I got them home and started poking around. I found the compressor is driven by a 24V 3-phase signal. I happened to have a beefy 3-phase brushless motor driver (ESC) leftover from a UAV project a decade ago:
+{{:projects:laser_cutter:work_logs:pasted:20220331-004159.png}}
+Slightly concerned they couldn't spell "red".
+I measured around 0.340Ω on the windings of the compressor versus 0.170Ω on the chunky brushless motor paired with the ESC. Vaguely in the same ballpark. The specs on the Aspen chiller said the PSU draws 10A at 24VDC, however the ESC could happily supply 100A. This will kill the compressor.
+{{:projects:laser_cutter:work_logs:pasted:20220331-004955.png}}
+Worth the risk!
+I hooked up the compressor to one of the ESCs and attached a UAV signal receiver to it. I gradually increased the "throttle" and the compressor started whirring! The cold side got cold and the hot side got hot! A miracle!
-The attiny10 is very tiny, only 1kB of flash and no EEPROM. The code that blinks the LED and the pattern for the blinking must share the same 1kB of space. I wrote some python code to digest a string of text and convert it into an on/off LED sequence. The code running on the microcontroller just needs to wake, read the next bit, set the LED accordingly, then sleep for 100ms.
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