Pure carbon is deposited on ceramic substrate by thermal decomposition of hydrocarbon at 10000C. The sheet resistance of film is controlled by controlling the thickness of the carbon film.
Range of values 1 ohm to 107 ohms
Temperature coefficient of resistance -1000pm/0C
Stability < 3%
Tolerance > 2%
Working voltage 500 volts
Working temperature -40 to 1200C
APPLICATIONS: These resistors are used in measuring instruments where close tolerances are required. These resistors have better stability compared to carbon composition resistors. Voltage coefficient is small. Temperature coefficient is negative. For small value, size of carbon composition resistor. These resistors have no ability to withstand electrical overloads.