| 摘要 |
A first switch, mounted in a brake pedal pad, turns on in response to slight pressure and remains on during continuance of the pressure. A second switch turns on when the brake pedal is moved or when the brake hydraulic pressure reaches a predetermined level. Closing of the first switch starts charging of a capacitor through a resistor. Closing of the second switch completes a circuit that turns on a brake lamp. The second switch also energizes a relay coil in the emitter-collector path of a transistor. If the decaying charging current through the resistor is still sufficiently high by the time the second switch is closed, the before-mentioned resistor biases on the transistor and operates the relay. The latter brightens the illumination of the lamp or flashes the lamp on and off. If, by the time the second switch is closed, the capacitor is already charged, no further charging current flows through the resistor. The transistor remains non-conductive and there is no change in the brake lamp. Thus, abrupt application of the brakes produces bright illumination or flashing illumination of the brake lamp. Normal slower application of the brake pedal produces a normal illumination of the lamp.
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