| 摘要 |
PURPOSE:To reduce the number of parts and to improve reliability by multiplying a signal by a frequency multiplier, and outputting the signal having a constant frequency without excess or shortage at a low speed rotation. CONSTITUTION:The frequency multiplier 2 generates a rectangular wave C1 having the constant frequency of 3kHz at the low speed rotation of 500rpm or less of the engine speed, and generates a rectangular wave C2 having the frequency four times the input signal at the high speed rotation. The output signal of a counter 32 becomes a reset signal of a gate pulse (f). The rectangular waves C1 and C2 pass a gate circuit. Rectancular waves f1 and f2 each having 4 pulses are outputted for every one input signal. The signal f1, which is obtained at the low speed rotation of 500rpm or less, is shifted from the signal for every one degree. However, accurate control which is synchronized with the rotary angle is not required at the rotation number of an idle rotation or less. Therefore, the signal can be used as the rotary angle signal for the control of an internal combustion engine. In this way, the number of the parts in the rotary angle detecting device can be reduced, and the costs can be reduced. |
