I have attempted to characterise the response of the C245 thermocouple at the request of mooshoomatt.
T245 handle connected to unisolder with C245-768 cartridge was clamped in place C245-937 cartridge was clamped in place so both tips are touching A solder blob was added as a thermal bridge between the cartridges Multimeter positive lead was connected to core connection of C245-937 cartridge Multimeter negative lead was connected to outer shell connection of C245-937 cartridge Power supply positive lead was connected to core connection of C245-937 cartridge Power supply negative lead was connected to middle sleeve connection of C245-937 cartridge
Unisolder was turned on and set to test temperature Power supply was turned on at 12V 5A briefly to heat soak C245-937 cartridge Multimeter displayed value in mV was allowed to fall until it reached steady state Value was recorded
I repeated first few temperature points with ~18 hour difference, multimeter readings all within within 0.06mV Readings are quite linear but don't appear to match standard thermocouples Needs to repeat with different cartridges to confirm
Greatscott didn't check the core to sleeve resistance (also 0R), otherwise he might have realized he is actually passing current through the TC junction.
I've attached a cutaway of a 245 cartridge that should make things clear.
Also here is the connection direections from sparkybg:
3. JBC C245: - Outer shell (green wire) connected to (mains)EARTH and SENSEB - Heater positive(red wire) connected to Vout1- and SENSEA - Heater negative(blue wire) connected to Vout1+ - 150ohm between ID and Vout1- - 5.6k between ID and Vout2-
Thanks! I'm still tweaking some things but the core is for the most part done.
Does anyone know if we can bump up the max power for the T245? I know it's currently configured to 130 Watts but was wondering if there was any reason from bumping it up to 150 or 160. I currently have a 160 VA transformer.
The maximum output current in the firmware is 6A (found in PID.c) @ 24V = 144 Watts, so if you want to set profile above that you will have to change code slightly
I have 160VA transformer too and would offer to test, but I'm not sure about process to build hex if you need XC32 v1.33 compiler (paid)?
The controller is made to control single instrument with one or two heaters. The heaters can be different (iron profile in the firmware has separate part for each heater), but they are always driven with the same temperature and in the same time.
However I can only see 1 variable for max power in iron.c so your profile will likely be either very overpowered for C210 or very underpowered for C245