To provide an operation control circuit (safety circuit) for machinery whereby a high degree of safety is established.
A switch K11 is admitted to move to the On position interlocking with the On operation of a start switch P actuated by an operator etc., under the condition that a relay switch *K2 on a line E is in On condition and a solenoid coil B1 is fed with current. The switch K11 is attracted and held in the On position by a solenoid coil B2 on the condition that the switch K11 has moved to the On position interlocking with On operation of the start switch P. When the magnetic attracting force of the solenoid coil B2 goes out, the switch K11 is moved to the Off position. Thereby the machinery is started by the start switch, and emergency stop can be made with an emergency stop switch, and even if melting, deposition etc., occurs in electric contacts, the emergency stopping function can be maintained certainly, and further it is possible to hinder restarting in the case that the melting deposition etc., has occurred in the electric contacts of a safety circuit.
ICHIKAWA KENJI
MOTOYAMA TATEO
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