Hello,
This is my first post here, and just putting it out there from the start, I am no expert in electronics. I am looking for some guidance on putting together a small temperature controller for an EV vehicle conversion. What I am missing is a simple controller that will measure temperatures of two cooling loops and use PWM signals to control two pumps, a heater, and switch on a fan. Below is a more detailed description. BTW if this is not the right place to post this, by all means let me know.
- I am using a LM7805 along with the recommended two capacitors to power a Nucleo-L432KC
- I am reading out 2 automotive temp sensor, supplying a 5V reference signal and reading out the resistance through a voltage divider setup (R1 & R2). I am not sure yet the total resistance required to ensure not to exceed 3.3V at A0 and A1 as I have to get the sensor and measure their resistance/voltage over the temperature range
- I use 3 2N2222 transistors with 2 resistors each to level shift the PWM signal to 12V. I need to generate between 9 and 300Hz with a max 50mA signal to be fed to PWM-controlled water pumps and a water heater (Q2, Q3, Q4 - https://octopart.com/2n2222a-diotec-31147100)
- I have one switch, pulling to ground, to activate a relay for a FAN (Q1 - https://octopart.com/2n2222a-diotec-31147100) Lastly, I am using a MCP2551 chip to enable CAN communication. This is not essential at the moment, but all the other controllers have CAN, so it would be a helpful feature.
- It all connects to a Deutsch connector and is meant to fit into a small enclosure
- All resistors are 0.25W
I basically put this together from online research but am at a point where some expert input might be good. So the simple question is, they way the circuits are drawn up, will they perform as described above?
Any comments welcome.
