Hello there, I'm so rusty at this stuff I squeak. Quick into, I graduated from a CET about 20 years ago. Back then, I could build circuits in my sleep. Since then, I've moved onto industrial instrumentation, and my circuit level electronics knowledge is long gone.
The project I need help with is a smoker temperature controller for my Primo XL. The simplest and most well known option is a small fan (around 10 cfm) to provide the intake draft, with feedback and control provided by a PID temperature controller.
Generally, the 12 Vdc fan is run in the on/off mode, but this presents a few issues. I would prefer a linear control, but that has problems as well. I just need some sort of offset adjustment on an amplifier circuit, I guess, to account for the fan start-up voltage probably not being 0V dc. I would like to be a able to adjust that bottom voltage so that the 0% output from the controller (4mA, 1Vdc or 2.4vdc to the amplifier input) is 0Vdc out of the amp, and 1% becomes a voltage of 3-6 Vdc (or whatever the startup voltage for the fan is). And 100% is 12vDC.
Thanks.