公开(公告)号：US4352057A

公开(公告)日：1982-09-28

申请号：US276943

申请日：1981-06-24

申请人： Takashi Okada ,  Hiroshi Sahara ,  Fumikazu Otsuka

发明人： Takashi Okada ,  Hiroshi Sahara ,  Fumikazu Otsuka

IPC分类号： G05F3/16 ,  G05F3/22 ,  G05F3/26 ,  H03F3/347

CPC分类号： G05F3/265 ,  G05F3/22

摘要： A constant current generating circuit is provided which comprises first, second, third and fourth transistors of one conductivity type, each having base, emitter and collector electrodes, and a voltage supply source having first and second voltage terminals. In this case, the collector and emitter electrodes of the first transistor are respectively connected to the first and second voltage terminals with a first impedance between the collector electrode and first voltage terminal; the emitter electrode of the second transistor is connected to the second voltage terminal through a second impedance; the emitter electrode of the third transistor is connected to the second voltage terminal through a third impedance; the emitter electrode of the fourth transistor is connected to the second voltage terminal; the base electrode of the first transistor is connected to the emitter electrode of the second transistor; the collector electrode of the first transistor is connected commonly to the base electrodes of the second and third transistors; the emitter electrode of the third transistor is connected to the base electrode of the fourth transistor; and a current utilizing means is connected between the first voltage terminal and at least one of the collector electrodes of the second, third and fourth transistors.

摘要翻译： 提供一种恒流产生电路，其包括一个导电类型的第一，第二，第三和第四晶体管，每个具有基极，发射极和集电极，以及具有第一和第二电压端子的电压源。 在这种情况下，第一晶体管的集电极和发射极电极分别与集电极和第一电压端之间的第一阻抗连接到第一和第二电压端子; 第二晶体管的发射极通过第二阻抗与第二电压端连接; 第三晶体管的发射极通过第三阻抗连接到第二电压端子; 第四晶体管的发射电极连接到第二电压端子; 第一晶体管的基极连接到第二晶体管的发射极; 第一晶体管的集电极共同连接到第二和第三晶体管的基极; 第三晶体管的发射电极连接到第四晶体管的基极; 并且电流利用装置连接在第一电压端和第二，第三和第四晶体管的集电极中的至少一个之间。

公开(公告)号：US4385320A

公开(公告)日：1983-05-24

申请号：US277738

申请日：1981-06-26

申请人： Hiroshi Sahara ,  Shuji Ishikawa ,  Fumikazu Otsuka

发明人： Hiroshi Sahara ,  Shuji Ishikawa ,  Fumikazu Otsuka

IPC分类号： H03L7/091 ,  H04N5/12 ,  H04N5/04

CPC分类号： H04N5/12 ,  H03L7/091 ,  H04N5/126

摘要： An automatic frequency control (AFC) circuit is disclosed which comprises an oscillating circuit for generating repetitive pulses, a generator for generating comparison signals having a slope portion in response to the repetitive pulses, and a phase comparison circuit which compares the comparison signals, and synchronous (sync) signals and based on the comparison supplies control signals to the oscillating circuit. The AF circuit further comprises a limiting circuit connected between the comparison signal generator and the phase comparison circuit which limits the maximum and minimum levels of the comparison signals to predetermined levels, and thereby predeterminedly limits the control range of the AFC circuit.

摘要翻译： 公开了一种自动频率控制（AFC）电路，其包括用于产生重复脉冲的振荡电路，用于产生响应于重复脉冲的具有斜率部分的比较信号的发生器，以及比较信号的相位比较电路， （同步）信号并且基于比较将控制信号提供给振荡电路。 AF电路还包括连接在比较信号发生器和相位比较电路之间的限制电路，其将比较信号的最大和最小电平限制到预定电平，从而预定地限制AFC电路的控制范围。