Monday, December 7, 2015

Precision Resistors - UNS 4-T220 - Riedon

These Precision Shunt Resistors are designed for systems which have a fast changing electrical load. It has a Heatsink and is encapsulated in epoxy. The substrate is Alumina for Good Heat Transfer but with Electrical Insulation. It is a Resistor formed by a NiCr Foil. (Like Nichrome).

Precision Resistors - UNS 4-T220 - Riedon

 Precision Resistors - UNS 4-T220 - Riedon
Specifications
  • Resistance from 0.2 Ohm to 80 Ohms
  • Power Rating to 15 Watts
  • Resistance Tolerances to ±0.01%
  • TCR to ±1ppm/K
  • Load Stability to 0.01%
Here are some documents that will build your awareness on how Resistors work and their Thermal behavior. These are from a firm called Riedon who design manufacture custom resistors and special resistors used in tight design requirements.

Resistors are probably the most common and well known of all electrical components. Applying a resistor to a circuit normally requires (1) calculating the nominal values needed in the circuit application (resistance, power rating, etc.) then (2) developing acceptable tolerances for the resistor that ensure it will function properly in all extremes of the application.

Read up the "Temperature dependence and TC" - The absolute ohmic value of a resistor is temperature-dependent. Also the "Definition of terms in the specifications of Resistors."

Riedon Inc
300 Cypress Avenue Alhambra, CA 91801, USA