| 摘要 |
957, 699. Automatic speed control systems. PROTONA PRODUCKTIONSGESELLSCHAFT FUR ELEKTRO-AKUSTISCHE GERATE G.m.b.H. Oct. 25, 1962 [Oct. 25, 1961], No. 40378/62. Headings G3R and G3X. A transistorised speed control system for a small permanent magnet D. C. motor for a taperecorder or the like incorporates compensation for variable battery voltage. In Fig. 1, an "inherent" type voltage regulator provides a substantially stable voltage to a retroactive speed control system with I.R compensation for load current. Voltage regulator. A Zener diode D1 fed through a lamp L1 (or like temperature dependent resistor) and connected to the base of transistor T1 provides a stable voltage U2 from the variable battery voltage U1. A lamp L2 shunting T1 enables a smaller transistor to be used. A constant voltage low current supply U5 may be provided for a transistor amplifier. Speed regulator. A signal proportional to the back E.M.F. of the motor across potentiometer R2, R3 plus the armature current drop across resistor R4 is compared with a reference voltage across diode D2 in transistor T3 to control regulating transistor T2. In Fig. 2 (not shown) the two functions are combined by introducing a battery dependent voltage to the base of the comparison transistor T3 through resistors R2, R4. |
