| 摘要 |
<p>An integrator circuit is reset at predetermined engine crank angles to develop a sawtooth waveform representing engine crank angle. A comparator circuit, including an adjustable, voltage source output, is connected in a closed feedback loop around the integrator to regulate the peak of the sawtooth to a predetermined magnitude which is independent of engine speed, and, hence, independent of the sawtooth frequency. The analog output of the comparator represents engine speed. An adjustable calibration resistor in the integrator adjusts the integrator output to secure a desired relationship between the output of the comparator circuit and the frequency of the sawtooth. The complete circuit requires only two operational amplifiers and a small number of passive circuit elements.</p> |
