TO-3 at Motorola around 1955. The lead spacing was originally intended to allow plugging the device into a then-common tube socket. The metal package can be attached to a heat sink, making it suitable for devices dissipating several watts of heat. Thermal compound is used to improve heat transfer between the device case and the heat sink. Since the device case is one of the electrical connections, an insulator may be required to electrically isolate the component from the heatsink. Insulating washers may be made of mica or other materials with good thermal conductivity. The case is used with high-power and
C-element slow environment. Note that the definition of C-element can be easily generalized for multiple-valued logic or even for continuous signals: For example, the truth table for a balanced ternary C-element with two inputs is Depending on the requirements to the switching speed and power consumption, the C-element can be realized as a coarse- or fine-grain circuit. Also, one should distinguish between single-output and differential realizations of C-element. Differential realization is possible using only NANDs (only NORs). A single-output realization is workable if and only if: There is a number of different single-output circuits of C-element built on logic gates. In