| 摘要 |
PURPOSE:To readily and accurately regulate the duty factor and the phase of a tachometer by a simple method by providing the first display means for maximizing the indication when a pulse width becomes 50% and the second display means for indicating by obtaining the ratio of phase difference. CONSTITUTION:A light from light emitting elements 1a, 1b is output through a tachometer disc 2, photoreceptors 3a, 3b as pulses (1), (2). The pulse (1) is output through T-type FF6, and a counter 12a as a counted value T0 of the pulse width. The pulse (1) is counted for the period by the counters 12b, 12c, and the minimum value T3 of the counted value is selected through the minimum selector 13a, and output to a divider 15a. The pulse (2) is also similarly processed, and the minimum value Te is output to the divider 15b. The dividers 15a, 15b respectively divide the input minimum values T3, Te by the counted values T0, and the numerical value is indicated on an indicator through indicating circuits 16a, 16b and multiplexers 17a, 17b. The variable resistors VR1, VR2 of the photoreceptors 3a, 3b are regulated so that the indicated value at this time becomes maximum. |
