Table Des Matières - Hitachi VTMX900ECT Manuel D'entretien

2-8
Circuit descriptions
1. Switched-mode power supply PS (PS Part) ................................................................................................................................................ 9
1.1 Technical data: ................................................................................................................................................................................................ 9
1.2 Functional principle: ....................................................................................................................................................................................... 9
1.3 Supply voltage part ......................................................................................................................................................................................... 9
1.4 Start-up with Mains-on: .................................................................................................................................................................................. 9
1.5 Normal mode: ................................................................................................................................................................................................. 9
1.6 Overload, power limitation, burst mode: ...................................................................................................................................................... 10
1.7 Standby mode: ............................................................................................................................................................................................. 10
2. Operating unit DC (DC part) ........................................................................................................................................................................ 10
2.1 Evaluation of the keyboard matrix ................................................................................................................................................................ 10
2.2 IR receiver and signal evaluation ................................................................................................................................................................. 10
2.3 Activation and function of the VFD display .................................................................................................................................................. 10
3. Central Control AIO (AIO part) .................................................................................................................................................................... 11
3.1 Analogue interface to the µC: ....................................................................................................................................................................... 11
3.2 Tape end - LED control : ............................................................................................................................................................................... 11
3.3 CMT detection (video detection with CSYNC) ............................................................................................................................................. 11
3.4 EE-PROM ..................................................................................................................................................................................................... 11
3.5 Easy link (P50) ............................................................................................................................................................................................. 11
3.6 Shuttle: ......................................................................................................................................................................................................... 11
3.7 Satmouse ...................................................................................................................................................................................................... 11
4. Deck electronics DE (DE part) .................................................................................................................................................................... 11
4.1 CTL stage ..................................................................................................................................................................................................... 11
4.2 Power on reset (POR) generator ................................................................................................................................................................. 12
4.3 The sensor interface : ................................................................................................................................................................................... 12
4.4 Interface to the head drum motor driver part ............................................................................................................................................... 12
4.5 Interface to the loading motor driver part: .................................................................................................................................................... 12
4.6 Interface to the capstan motor ..................................................................................................................................................................... 12
5. Front end FV (FV part) ................................................................................................................................................................................. 13
5.1 The front end comprises the following parts : .............................................................................................................................................. 13
5.2 The front end has been designed to receive the following systems: ........................................................................................................... 13
5.3 Tuner modulator (TUMOD) ........................................................................................................................................................................... 13
5.4 IF selection ................................................................................................................................................................................................... 13
5.5 IF demodulator ............................................................................................................................................................................................. 13
5.6 Audio demodulator ....................................................................................................................................................................................... 13
6. Video signal processing VS (VS part) ........................................................................................................................................................ 13
6.1 Switchover functions in the signal electronics IC LA71595M [7004]: .......................................................................................................... 13
6.2 Recording : ................................................................................................................................................................................................... 14
6.2.1 Luminance ................................................................................................................................................................................................. 14
6.2.2 Chrominance PAL ...................................................................................................................................................................................... 14
6.2.3 MESECAM ................................................................................................................................................................................................ 14
6.2.4 SECAM L ................................................................................................................................................................................................... 14
6.2.5 FM signal ................................................................................................................................................................................................... 14
6.3. Playback: ..................................................................................................................................................................................................... 15
6.3.1 FM signal ................................................................................................................................................................................................... 15
6.3.2 Luminance ................................................................................................................................................................................................. 15
6.3.3 Chroma PAL .............................................................................................................................................................................................. 15
6.3.4 Chroma MESECAM ................................................................................................................................................................................... 15
6.3.5 Chroma SECAM L ..................................................................................................................................................................................... 15
6.3.6 NTSC ......................................................................................................................................................................................................... 15
6.3.7 PAL M,N ..................................................................................................................................................................................................... 15
6.4 General ......................................................................................................................................................................................................... 15
7. Audio linear (AL part) ................................................................................................................................................................................... 16
7.1 Audio I/O for the 1-scart version ................................................................................................................................................................... 16
7.2 Audio I/O for the 2-scart version ................................................................................................................................................................... 16
7.3 Audio linear recording ................................................................................................................................................................................... 16
7.4 Audio linear playback .................................................................................................................................................................................... 16
7.5 Audio linear muting ....................................................................................................................................................................................... 16
8. Audio HiFi - for stereo units (AF part) ........................................................................................................................................................ 16
8.1 General ......................................................................................................................................................................................................... 16
8.2 Audio I/O ....................................................................................................................................................................................................... 16
8.3 Audio HiFi recording ..................................................................................................................................................................................... 16
8.4 Audio HiFi playback ...................................................................................................................................................................................... 16
8.5 Interface to the audio linear .......................................................................................................................................................................... 16
9. IN/OUT (IO part) ............................................................................................................................................................................................ 17
9.1 Video: ............................................................................................................................................................................................................ 17
9.1.1 Audio for the 2-scart version: .................................................................................................................................................................... 17
9.2 Decoder mode: (REC or STOP) ................................................................................................................................................................... 17
9.2.1 Program position with decoder (front end) ................................................................................................................................................ 17
9.2.2 External input with decoder ....................................................................................................................................................................... 17
10. Follow Me (FOME part) .............................................................................................................................................................................. 17
11. VPS/PDC, on-screen display (VPO part) .................................................................................................................................................. 17
11.1 VPS/PDC .................................................................................................................................................................................................... 17
11.2 OSD-PART .................................................................................................................................................................................................. 17
GB