This very popular type of controls provide a proportional temperature control combined with integral and derivative temperture control. Proportioning the heat means less power to the heater is supplied if the heat is closer to the setpoint. This is achieved by the derivative and integral operating modes. The controllers come with set parameters which may be adjusted to your application. One of the industries work horses is the PID controller ETR 9090 from Ogden.
This guideline helps you understand the basic function of a temperature controller.
Manuals and specifications for Ogden's ETR PID controller:
1. Select PID Controller size:
Most popular sizes:
2. Determine what Inputs will feed the PID controller:
The signal input (T/C, RTD or voltage) on most standard controllers (example Ogden's ETR 9090) must be selected at the time of ordering.
3. Decide which control operation is required for the PID control
Most PID controllers come standard with two main control functions.
"fuzzy-logic" controllers is just another marketing term for this type of controllers...
4. Ensuring you have enough outputs from the PID controller
If only heating (and not cooling) is required, one output is enough. Output can be to a relay, SSR or SCR, pulsed voltage, linear voltage or linear current.
To protect your equipment further, we recommand a high temperature relay alarm output. The cost for this safety is less than $ 20.00...
Programming the PID controller
Order and names of parameters vary among control manufacturers, but the parameter names are usually very similar. Programming tools are useful if sets of saved parameters need to be downloaded through an interface (RS 485, RS 232) into different controls or for integrating several controllers into a higher control.
Examples of ETR 9090 PID controller configurations: