Electric dryers are of three general types. They are:
Timer controlled:
Timed drying dryers are ones where you can set the time on the dial. The dryer stops as soon as the time set by you is reached. Some dryers may have a 4-10 minute cool down period. It is vital that you avoid over drying by setting the timer for a short period as possible. The results of such dryers depend on the ability of the user and their judgment of drying time as loads differ in type of fabric, size and amount of moisture content present. Timed cycles are present in low priced dryers.
Automatic Drying:
These dryers automatically recommend two or three usual drying cycles. They are Permanent Press, Regular, and Knit/Delicate. You have to just set the preferred degree of dryness on the "More or the less dry" controls. The load will dry to the temperature or moisture level set by you. A cooling period is also included before the dryer stops. An automatic drying unit senses the temperature of the exhausted air.
Electronic Sensor Drying:
These are newer and are more expensive. They use an electronic moisture sensing device. This device actually measures the degree of moisture in the fabric. When the degree of dryness selected by you is reached the dryer will automatically shut off. Cool down period is also included. Electronic sensor drying is the best and most competent drying method.
Electric dryers are almost maintenance free. But you can take some more extra care so that you have a problem free dryer operation.