Control rod position detector

Purpose: To improve the reliability of a position signal by controlling the voltage between input winding ends reversely responsive to the varied component of a standard level of an output winding induced voltage even if the temperature of primary coolant is altered to vary the output winding induced voltage after a control rod is retained at standard position. Constitution: When primary coolant is at standard temperature, a position signal corresponding to the standard position is produced. When the temperature of the primary coolant is raised to raise the voltage induced at the output winding, an electric current flowing through a transistor and a resistor is increased. Thus, the voltage drop across the resistor is increased to lower the voltage applied to the input winding so as to correct the variation of the position signal due to the temperature rise of the primary coolant. When the temperature of the coolant is lowered, the reverse operation to the above is executed to correct the variation of the signal. (Sekiya, K.)