摘要 |
The relay circuit consists of an instantaneous element setting unit (A), a negative current rectifier circuit unit (B), an automatic return overload relay unit (D), a delay unit (E) and a circuit test unit (F). Also transistors (Q1-Q5), selection switches (SW1-SW3), an LED, a thermistor (TH), and an auxiliary relay (RY) are included. An overload, is displayed by the LED and the relay is turned off through the transistor (Q4) after a time limit predetermined by a capacitor (C2). For a short-circuit, the instantaneous element setting unit turns off the relay. The selection switch (SW2) enables automatic return function while another switch (SW3) enables the selection of definite or anti-definite characteristics. |