Hi, i have a couple of questions. 1-)I want to control temperature of water which has a constant volume with 220VAC current and a heating element precisely (error should be betweeen 0.1-0.3 degree celsius). But i can't decided what should i use for controlling AC power. There are many many options like solid state relay, mosfet, triac etc. As far as i understand these options provides on/off control. I want to use PID control too. Are there any other options for regulating AC power continously (not on/off like regulating current)?
2-)In addition, temperature range will be between room temperature and 45 celsius. So the heating element and 220VAC maybe too powerfull for this project. Do you have any other suggestions for heating? (Actually i prefer less power and DC current for portability and security)
NOTE: Heating time is important. I have not much knowledge about electronics so please explain simply. Thank you for your answers.