I
Hello Guys,
I'm working in a project where I have to program a controller for a heater (glow bar, heating rod). Of course I know the theory of PID. But I don't know how I can apply it for this project. For example: the heater "knows" only ON-OFF. The Question is, what's bout the PID-Set Value. Do I use it in a PWM-Simulation (e.g. PID-Value calculate me 8 --> PWM 8 => 20ms ON, 80ms OFF. PID-Value 2 --> PWM 2=> 80ms ON, 20ms OFF) or do I have it to use for new Temp-Calculation. For example PID returns me 30. My Actual Temp is 70°C so new temp is 70°C-30°C=40°C... and then if-then->
If (newtemp>settemp+5) Heater_OFF();
If (newtemp<settemp-5) Heater_ON();
What to know is, the Heater is very powerful. I made a Test: I switch the Heater on and let it on until 150°C and then I shut it off. It increased in 33 sec from 24°C until 150°C (increase rate of 4°C/s). And it "burned after" until 182°C in 12 sec. In Cooling-Mode it have a cooling rate of -0,16°C/s.
What are you thinking? Please help.
I'm working in a project where I have to program a controller for a heater (glow bar, heating rod). Of course I know the theory of PID. But I don't know how I can apply it for this project. For example: the heater "knows" only ON-OFF. The Question is, what's bout the PID-Set Value. Do I use it in a PWM-Simulation (e.g. PID-Value calculate me 8 --> PWM 8 => 20ms ON, 80ms OFF. PID-Value 2 --> PWM 2=> 80ms ON, 20ms OFF) or do I have it to use for new Temp-Calculation. For example PID returns me 30. My Actual Temp is 70°C so new temp is 70°C-30°C=40°C... and then if-then->
If (newtemp>settemp+5) Heater_OFF();
If (newtemp<settemp-5) Heater_ON();
What to know is, the Heater is very powerful. I made a Test: I switch the Heater on and let it on until 150°C and then I shut it off. It increased in 33 sec from 24°C until 150°C (increase rate of 4°C/s). And it "burned after" until 182°C in 12 sec. In Cooling-Mode it have a cooling rate of -0,16°C/s.
What are you thinking? Please help.