| 摘要 |
PURPOSE:To stabilize the operation of a meter pointer during the OFF period of an ignition switch, by prohibiting the action of a driving section when either a power source voltage or a control signal voltage drops below a specified value. CONSTITUTION:This meter is made up of a control section 1 which generates a signal varying with a specified function characteristic according to changes of an input signal (e.g. vehicle speed signal) and a driving section 2 which controls the direction of forming a magnetic field of a cross coil 3 by regulating the current supply direction and supply current value with respect to the cross coil 3 based on the signal. To run current to the cross coil 3 in both directions, normal and opposite, the driving section 2 has a so-called H switch type circuit composed of current driving type transistors (Tr) 20-25. Then, the Trs 21 and 24 are so arranged to perform the function as operation prohibition means and the operation limit voltage thereof is set, for example, above 2V. This blocks the reception of any signal to forbid the operation of the driving section 2 when the power source voltage or an output voltage of the control section 1 are below 2V.
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