Board - Sony SNC-WR632C Service Manual

Motor are two-phase drive stepping motors.
In this unit, the motors are driven using sine waves so that they smoothly rotate.
Moreover, waves required for correction are superimposed on the sine waves so as to correct the irregular
torque proper to the motors.
A motor drive waveform is output from the PWM system-based D/A connector of a microcontroller.
The output drive waveform is eliminated in high frequency using a filter and generated as a motor drive
waveform through a driver.
The output waveform of the driver is balance-driven, and a waveform that is opposite in phase is applied
to each driving coil.
4-5. HC-51 Board
The HC-51 board controls the internal temperature by driving of a heater and generates the driving volt-
age of an internal fan.
Outline
The HC-51 board controls heaters that warm the internal temperature and fans that circulate the internal
air so that the unit can be stably operated in the outdoor air temperature environment (of _40dC to 50dC).
The heaters and fans controlled by an HC-51 board are as follows:
. In-heater: Heaters 1 and 2 (Rubber heaters of 25 W)
. In-air circulating fan: Fans 1 and 2 (12 VDC fans)
The HC-51 board monitors the temperature in the center of this unit and drives heaters and fans according
to the temperature. By this control of temperature, the internal temperature of this unit is kept in a state
where a camera system can be stably operated.
The main power of the camera system is controlled by the HC-51 board. The power to the camera system
is stopped in a state where the internal temperature is not sufficiently warmed.
When the fans driven using the HC-51 board are not normally operated due to a failure, the information is
detected and notified to the system microcontroller on an SY-416 board as an alarm signal.
Detailed description
Power block
. During feeding of 24 VAC
A power of 24 VAC input to this unit is input to CN5002 on an HC-51 board.
On the HC-51 board, the power input to CN5002 is distributed to a PS-858 board. The distributed power
branches to two paths. In one path, the power is output to CN5001. In other path, it is rectified and used
for the control system on the HC-51 board.
The power used for the control system on the HC-51 board is rectified using D5003 and C5016 to C5020
and then generated as 12 VDC using a DC/DC converter by IC5002. 9 VDC is generated from 12 VDC
using series regulator Q5503 of 12 VDC.
IC5003 is a DC/DC converter that generates 24 VDC. During feeding of 24 VAC, it is in a stop state.
4-7 (E)
SNC-WR632C/WR602C