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==== TCR (Temperature Coefficient of Resistance) ==== * The parts should be chosen so that the [[https://www.mouser.com/blog/dont-ignore-current-sense-resistor-tcr|TCR doesn't produce too much change in the heater current]]. * Maybe its not much of a big deal since we have a temperature sensor for the feedback, but in some cases this circuit could be used as an open loop heater. * [[http://vishaypg.com/docs/63609/63609.pdf | Vishay Precision]] has some metal foil resistors with 0.2 ppm/C. The best from anyone else is 2 ppm/C. Most resistors are more like 20-200 ppm/C. |
- DC Current source
Max current > 1 A
- Takes unfiltered DAC signal as input (differential)
- LED power indicators
- Heater power unregulated (but filtered?)
- Regulators inside for the opamps
Related ELOGs
TCR (Temperature Coefficient of Resistance)
The parts should be chosen so that the TCR doesn't produce too much change in the heater current.
- Maybe its not much of a big deal since we have a temperature sensor for the feedback, but in some cases this circuit could be used as an open loop heater.
Vishay Precision has some metal foil resistors with 0.2 ppm/C. The best from anyone else is 2 ppm/C. Most resistors are more like 20-200 ppm/C.