Does whirlpool dryer set temp or average temp during cycle?

Dryer without circuit boards seems to turn shorty heating element on and off at a slower rate for Low Temp Setting, but a faster rate for Med and High Temp Settings.  Is this right, or should dryer run at a steady set temperature like 130F. on Low, 140F, on Medium, no 155F on High. Heating element temp at dryer exhaust vent seems to be 155F when element is on. Thermostats and Cycling Thermostat are OK.