Power levels
The number of power levels (adjustments) provided in the device.
The more levels provided in the design (with the same maximum power) — the more precisely you can adjust the heating to your preferences. On the other hand, the abundance of adjustments affects the complexity and price of the device, despite the fact that there is not always a need for this. So, for electric sheets (see "Type"),
2 – 3 modes are quite enough — intensive for preheating and one, less often two workers. On the other hand, the opposite situation occurs —
6 or even more power levels.
Auto-switch of power level
Function
of automatic power reduction of the heater.
The point of this function is that after a long (usually about 2 – 3 hours) operation at high power, the heater automatically reduces the heating intensity. This avoids overexpenditure of energy and overheating of both the device itself and the user. Auto-switch of power level is especially relevant during sleep, when the user cannot independently control the operating mode; therefore, this function is found mainly in electric sheets (see "Type"). In some models, it can be turned off; this point, as well as other features of the work, should be specified separately in each case.
Note that automatic switching from fast mode (see above) to normal mode is not considered auto-switch power — despite the general similarity, these are different functions.
Auto switch-off
The ability
to automatically turn off the heater after a certain time.
Auto switch-off performs three main functions. Firstly, it provides safety: even if the user forgets to turn off the heating pad, it will not overheat and cause a fire. Secondly, the overheating of the user himself is thus prevented; this is especially convenient if the heating pad is used during sleep. Thirdly, auto switch-off allows you to avoid unnecessary power consumption.
Note that the response time and features of its adjustment may be different. So, in the simplest models, only one option is provided (for example, after 90 minutes), more advanced devices may have
several time settings or even the ability to set it yourself within a certain range.
Operating time
The operating time is the time until the device auto-shutdown. Therefore the time during which a sheet or blanket works on heating. There are models with an adjustable shutdown timer, which allows you to set the required time for the device to automatically turn off.