EM coil for valves with temp. compensating resistor - has sec. winding parallel to resistor arranged on body of main coil and driven in opposite sense

摘要

The electromagnetic spool for valves has temperature compensation circuitry including a temperature dependent resistor (NTC) in the current line. A secondary coil (5) is connected in parallel with the resistor (NTC). This coil (5) is arranged on the body of the main coil (2) and is driven in the opposite sense to the main one (2). The resistor (NTC) and both coils are pref. formed as a single component encased in plastics material. USE/ADVANTAGE - For proportional valves operated, e.g. by pulse-driven e.m. coils for pressure or through controls used for electric pressure transducers to control turbo exhaust gas flow valves. Provides almost constant magnetic force over wide temp. range.