| 摘要 |
<p>The low cost speed governor for internal combustion engines may be completely powered by the ignition coil. The governor receives a periodic signal from the primary ignition winding (W1) that is indicative of the actual speed of the engine. A pulsed speed signal is generated that is functionally related to the periodic signal. The pulsed speed signal had a pulse width that is functionally related to the actual engine speed. A pulsed reference signal is generated by a timer circuit (U4), and has a pulse width that is functionally related to a predetermined reference speed. The pulsed speed signal is then compared with the pulse reference signal by a comparator circuit (G12), and a pulsed error signal is generated that has a pulse width which is functionally related to the difference between the speed signal pulse width and the reference signal pulse width. The speed of the device is then changed by a transistor bridge network as a function of the error signal.</p> |
