6 ms·
You are still talking about different systems dispute them both having to do with temperature. An AC unit can only be on or off, so you need a window, hysteresi
by dokem 6y ago
You are still talking about different systems dispute them both having to do with temperature. An AC unit can only be on or off, so you need a window, hysteresis, to keep from toggling on and off constantly. If you can input an analog signal, like control how much power goes into the heating coil in a BBQ, the PID is applicable. PID, if tuned properly, will find the right amount of power to feed the heating element to keep the oven at the desired temperature. This is not possible if you can only turn the AC on/off with significant lag, so you need hystereiys.
- lucianbr 6y agoPID can be used with an on/off control, you do something like PWM: on X minutes out of every hour, and vary the X as the analog parameter. Don't know how easy that is on the AC/heating, but as far as the control system, it works, and it's PID.
- conk 6y agoPID can’t be used for control of any device that uses a relay. PWM will have the effect of just changing the coil voltage. Even if you could switch a relay on/off quickly you’d just prematurely burn out the contacts. PID is only effective with solid state switching devices, which are not really common for residential heating/cooling.