Kenwood TK-2207 Service Manual page 18

TK-2207
2) Memory Circuit
Memory circuit consists of the CPU (IC405) and an EEPROM
(IC406). An EEPROM has a capacity of 64k bits that contains
the transceiver control program for the CPU and data such
as transceiver channels and operating features.
3) Low Battery Warning
The battery voltage is checked using by the microprocessor.
The transceiver generates a warning tone when it falls below
the warning voltage shown in the table.
(1) The red LED blinks when the battery voltage falls below
the voltage (1) shown in the table during transmission.
Note:
The transceiver checks the battery voltage during reception
even when, in the FPU, the Battery Warning status function
is set to "On TX" (default setting).
However, the LED does not blink during reception. During
transmission, the LED blinks to generate the warning tone
of a low battery voltage.
(2) The transceiver immediately stops transmission when
the battery voltage falls below the voltage (2) shown in
the table. A message tone beeps while the PTT switch
is released.
Ni-Cd Battery
(1) 6.2[V]
(2) 5.9[V]
18
CIRCUIT DESCRIPTION /
IC405
CPU
Fig. 9 Memory circuit / 图 9 存储器电路
Ni-MH Battery
6.2[V]
5.9[V]
R404
SB
Fig. 10 Low battery warning / 图 10 电池低压警告
电路说明
2) 存储器电路
存储器电路由 CPU (IC405) 和 EEPROM (IC406) 组成。
有 64k bits 的容量，包含 CPU 用的手持机控制程序以及信道
和操作功能这样的数据。
IC406
EEPROM
3) 电池低压警告
通过微处理器监视电池电压。当低于警告电压时将发出警告
音。
(1) 发射中，当电池电压低于电压 (1) 时红色 LED 闪烁。
注∶
即使电池电压警告功能在 FPU 中被设置为"On TX" (默认设
定) ，手持机在接收时也检测电池电压。
但是在接收期间 LED 指示灯并不闪烁。发射时电池电压过低
LED 会闪烁并产生警告音。
(2) 当电池电压降到电压 (2) 以下，手持机将立刻停止发射。
PTT 开关放开时会有一声提示音。
镍镉电池
（1） 6.2 [V]
（2） 5.9 [V]
IC405
88
CPU
镍氢电池
6.2 [V]
5.9 [V]