A student designs an electronic sensor to monitor whether the temperature in a refrigerator is above or below a particular value. The circuit is shown in the figure below.
Name the components used in the output device.
The output device of the circuit in the figure above is changed so that the new output device may be used to switch on a high-voltage circuit.
State the component that is used in the new output device.
Draw on the figure below to show how the component in (i), together with a diode, is connected so that the high voltage may be switched on when the output of the op-amp is negative.
