For my project, I need to heat up a nichrome wire (which acts as a heating element) and provide a power of 100mW to it. I have already done computation and I need current of approximately 22mA to generate that power, also the voltage that will be generated across the heating element will be 4.51V. I am planning on using a NPN BJT as a current driver to limit the current at a constant rate and because my current requirement is lower than 1A, I think NPN BJT will be a better option than using MOSFET. I am using MCU connected to this nichrome wire through current driving circuit.
- Since, I'll have to provide a source voltage for the driving circuit, I plan on using a 3.6 V battery. The problem that I am confused about is, will my circuit work properly with 3.6V at source? Does 4.51V generated across heating element have any significance in regards to this?
- I researched about load switches which use P-channel MOSFET, because of it's lots of advantages, I am confused if it will be a better choice or not, if someone can suggest.
- Also, I read on a website that while using MCU, it's better to use a high side switch, since MCU always needs to be ground. So, on using an NPN BJT, wouldn't it work properly?