| 摘要 |
<p>PURPOSE:To prevent the erroneous operation due to noise by providing a signal coupling circuit for coupling a signal from a wheel diameter correcting switch to a printed card in the vicinity of the card, thereby increasing the voltage level for transmitting the signal from the switch to the coupling circuit. CONSTITUTION:A decimal counter 2 inputs an input pulse P and pulses C2''- C4'' from a signal coupling circuit 3 through an OR gate 1, and outputs dividing frequencies C1-C4.Synchronizers S2-S4 synchronize the dividing frequencies C2-C4 with the pulse CP of different phase from the input pulse P and output pulses C'2-C'4. The circuit 3 output pulses C''2-C''4 to the secondary side of a photocoupler PC1 when the pulses C'2-C'4 are inputted to the primary side of a photocoupler PC2 in response to the sets of wheel diameter correcting switches W2-W4. In this manner, a power source voltage V can be set to a value sufficiently higher than the noise induced at a long wire l.</p> |
