| 摘要 |
PURPOSE:To prevent an LED from emitting a light due to weak pulse generated when a switchig element and a voltage divider become defective by connecting a series circuit of a resistor, a capacitor and a resistor, a capacitor in parallel between the anode and cathode of the LED. CONSTITUTION:An impedance 8 is connected in parallel between the anodes and the cathodes of LEDs 1-1-1-n. The impedance 8 is a series circuit of a resistor, a capacitor or a capacitor, a resistor. A weak pulse current generated when any of transistors 2-1-2-m is shortcircuited or opened is bypassed through the impedance 8 so as not to flow through the LEDs 1-1-1-n. |
