![HYT TC-610P Скачать руководство пользователя страница 21](http://html1.mh-extra.com/html/hyt/tc-610p/tc-610p_service-manual_2194358021.webp)
TC-610P Service Manual
19
high level. Then Q611 becomes conductive and provides 5V voltage (TX_VCC) for the operating circuit
(Tx circuit).
The power supply of the Tx and Rx circuits are protected by symmetrical voltage regulation measures.
When output voltage/current changes along with the change of load, the close-loop feedback circuit
operates, regulating the output voltage to 5V.
8. VOX Realization Circuit
The block diagram is shown in the figure below:
Q202
2SA1832
1
2
3
Q201
2SK1824
2
3
1
J4
MICJACK
2
4
3
1
VCC_5V
R251
1M
MIC_EN
EXPTT
C260
220P
RXD
mic
X1
-
2
+
1
R201
2.2K
C201
470P
C200
4.7u/10V
R203
4.7K
VCC_5V
R200
470
C213
1U
C212
0.1U
R205
47K
C202
0.1U
L200
1UH
R202
100
TP200
R208
100K
R207
56K
R206
1K
R204
470
C274
0.01U
Figure 10
Press and hold down the programmed
VOX
key, and the radio enters the VOX status. The VOX can be
activated only when MIC_EN and EXT-PTT are detected by MCU to switch from low level to high level
within several hundred milliseconds. Otherwise, the earpiece will be deemed as non-VOX one and the
VOX function will not be activated.
1
)
When a VOX earpiece is plugged into the accessory jack, Q201 is cut off, and MIC_EN switches
from low level to high level. Meantime, Q202 and R204 form a closed circuit with the external
earpiece (Q202 is conductive), and EXT-PTT switches from low level to high level. In this case, the
VOX earpiece is determined by MCU, and the VOX function is enabled. When the VOX level