| 摘要 |
<p>990,115. Controlling clutches. ETABLISSEMENTS ED. JAEGER. July 19, 1961 [July 22, 1960; Oct. 31, 1960; Jan. 26, 1961], No. 26188/61. Heading F2L. The current for energizing a magnetic particle clutch used in a vehicle is so derived from the ignition circuit of the vehicle engine and supplied to the clutch coil through a transistor amplifier that the energizing current is proportional to the engine speed. As shown, a clutch coil 1 is connected to the collector 5 of a transistor, the base 8 of which is connected through a resistor 11 to the centre tapping of the secondary coil 12 of a transformer having its primary coil 15 in series with the primary coil 16 of an ignition coil and the contact 17 of a contact breaker. The ends of the secondary coil 12 are connected through rectifiers 13, 14 to the emitter 6 of the transistor which is also connected to the terminal 7 of a battery. The frequency of the signals reaching the transistor base 8 is equal to the frequency of opening of the contact 17, which is a function of the engine speed, and the current supplied to the clutch coil 1 is directly proportional to this frequency up to a limiting frequency, after which the transistor becomes saturated and a constant current is supplied to the clutch. Other circuits using transistors are described, and may include thermistors for correcting variations in the clutch and ambient temperatures; moreover a variable impedance may be connected in series with the clutch coil and be adjusted in accordance with the position of the accelerator pedal.</p> |
