A on off is exactly that it turns on and allows full power to hit the heating element. It shuts down when the probe runs over the set temp and back on again when under it. Pulse proportional is the same in fast motion. It runs power to the heating element and shuts down the power on and off rapidly, many times a second. The element is not allowed to get over the set point and not allow under it by flipping the power on and off the element never heats fully or cools fully.
proportional dimming units regulated the amount of power adding and dropping the power amount to regulate the temps. Pulse is usually on the higher end units and the lower end use dimming. The dimming will prevent the buzzing that is sometimes associated with some elements .
Reply With Quote