(20 13? Taizhou simulation) The device in the dotted box is called _ _ _ _ _ _, where R is thermistor, and its resistance decreases with the increase of temperature, and R0 is sliding.

Electromagnetic relay is equivalent to the switch in the circuit, so the device in the dotted box is called electromagnetic relay;

According to the meaning of the question, the current required for armature attraction is certain, that is, the current in the control circuit is constant;

To increase the starting temperature of air conditioner, the resistance value of thermistor will decrease. From I=UR thermistor +R slider, it can be known that the smaller the thermistor is, the larger the resistance of the sliding rheostat connected to the circuit is, that is, the slider will be fixed to the right under the condition of constant power supply voltage;

When the resistance of the sliding rheostat is constant, the smaller the thermistor, the lower the power supply voltage.

So, the answer is: electromagnetic relay; Right; decrease