README.md

   1 # heatpump
   2 Retrofitted controller for an IVT greenline 14e-9.
   3 The old controller gave up the magic smoke and this is my way to fix it.
   4
   5 The controller consists of a raspberry pi 3 with a DAQCplate for sensors and controlling relays.
   6 I am using the original NTC thermistors.  The sensors are connected: one lead to +5V, the other lead to ADC input, and a 1.5kΩ between ADC input and GND. This makes a voltage divider and 1.5kΩ fits the complete sensor range for the ADC.
   7 A 5v relay is connected to the output. +5V to flyback protection and the othera lead to GND. The 5V relay run the big 3-phase relay for the compressor.