Kenwood TK-2217 Service Manual page 29

TK-2217
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 the battery
voltage falls below the warning voltage (2) shown in the
table.
(1) The red LED blinks when the battery voltage falls below
the voltage (1) shown in the table during transmission.
Ttansmission is still allowed.
Note:
The transceiver checks the battery voltage during reception
even when, in the FPU, the Battery Warning status function
is set to "While Transmitting" (default setting).
However, the LED does not blink during reception. The red
LED blinks during transmission. The transceiver is still
usable.
(2) The transceiver immediately stops transmission when
the battery voltage falls below the voltage (2) shown in
the table. A warning tone sounds while the PTT switch
is pressed.
(1)
(2)
28
CIRCUIT DESCRIPTION /
IC405
CPU
Fig. 9 Memory circuit / 图 9 存储器电路
Ni-MH Battery
6.2[V]
5.8[V]
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 用的对讲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。 当低于表中所示警告电压 (2) 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。
仍然允许发射。
注∶
即使电池电压警告功能在FPU中被设置为 "While Transmitting
(发射时)" (默认设定) ，对讲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。 发射时红色LED会闪
烁 . 对讲机仍可以使用。
(2) 当电池电压降到电压 (2) 以下，对讲机将立刻停止发射。
PTT 开关放开时会有一声警告音。
（1）
（2）
IC405
R404
88
BATT
CPU
Ni-MH 电池
6.2 [V]
5.8 [V]