Digital processing circuit protection device

Abstract

Abstract PURPOSE:To prevent a device from entering into a runaway state, by providing a circuit for detecting whether a clock exists or not, on the way of a path of a start command signal of a device which is subjected to a digital control, such as a motor, etc., and sending a stop signal to the device to be controlled such as the motor, etc., irrespective of a state of the start command signal, when the clock does not exist. CONSTITUTION:When a fundamental clock generator 2 does not generate a clock signal (ck), if a start command signal ST is L, a motor is in a stop state. Subsequently, when the start command signal ST becomes H, the reset of a flip-flop 13 is released, but since the clock signal (ck), namely, a rise signal is not inputted to a T terminal, an output Q is not varied to H. Therefore, a motor starting switch 9 remains opened, and a motor 11 holds a stop state. In this way, when the clock signal (ck) does not exist, even if the start command signal ST is impressed, the motor 11 is not shifted to a start state, and does not become a runaway state.

Inventors

• 👤 Jun Kobayashi
• 👤 純 小林
• 👤 Keijiro Jinno
• 👤 神野　啓二郎
• 👤 Takashi Takahashi
• 👤 孝 高橋

Bibliographic Details