PURPOSE: To maintain an alarm signal output by exciting the coil of an alarm relay with an electric current discharged from a capacitor after a thyristor and a transistor are turned on by means of a trip signal and with an electric current limited by a constant-current diode by closing the first and second contacts and short-circuiting the transistor.
CONSTITUTION: A trip signal is impressed upon the gate of a thyristor 91 in an alarm signal (AL) output circuit 9 and turns on the thyristor 91. When the thyristor 91 is turned on, a transistor 92 is also turned on. As a result, an electric current is made to flow to the coil 101 of an AL output relay 10. When the coil 101 is excited with this large current, the second contact 103 is attracted and closes. Thereafter, the current of the AL output relay 10 flows to the coil 101 through a constant-current diode 95 and the closed second contact 104 and becomes a small constant current. Moreover, since the contact interlocked with the second contact 103 also closes when the coil 101 is excited, the AL output is turned on.
| WO/2000/002298 | ELECTROMAGNETIC RELAY |
HIROTSUNE KOJI
SATO KAZUYUKI
ARINOBU ICHIRO
