Theory of Operation
3–6
TSG 95 Service Manual
supply when a DC input voltage is applied to J5. F1 is a fuse used for safety pur-
poses. C64 helps with EMI. Q7 is on during normal operation. If a reverse volt-
age is applied to the DC input, Q7 shuts off to protect the power supply circuit.
VR1 limits the gate-source voltage of Q7. C57 and C56 control ripple on the in-
put voltage.
U22 allows the microprocessor (U2) to turn off the power supply. The power
supply for U22 is connected to a regulator (U25), which is connected to the input
voltage. This allows U22 to stay powered up even when the instrument is
switched off. When the ON key is pressed U22–10 gets pulled high; normally it
is pulled low by R30. U22B is connected to act as an inverter pulling U22A–4
low. This sets U22A–6 low, enabling the power supply controller (U27) through
U27–5. When the ON key is pressed again, U2 detects the key press, stores in-
formation for power up, and then drives the gate of Q5 high and then low. This
causes the drain of Q5 to be pulled low and then high, clocking the flip-flop
U22A. Since the Q output of U22A is tied to its input, the flip-flop toggles its Q
output high. This disables the power supply, shutting the instrument off. R70 and
C78 keep the instrument from coming on automatically when an adapter is
plugged in or new batteries are put in the instrument.
The –5 V supply voltage is generated off the +5 V supply through transformer
L9. CR1 and CR2 keep the current from flowing on the inactive parts of the
switching cycle for each supply. L9 also helps to filter the +5 V and –5 V sup-
plies along with C53, C54, and C77. L2 and L3 are used to filter the supplies
which are used in analog portions of the circuitry.
Содержание TSG 95
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Страница 29: ...Specifications TSG 95 Service Manual 1 15 Figure 1 3 PAL 75 Red and Red Field Figure 1 4 PAL 100 Red...
Страница 30: ...Specifications 1 16 TSG 95 Service Manual Figure 1 5 PAL Green Field Figure 1 6 PAL Blue Field...
Страница 31: ...Specifications TSG 95 Service Manual 1 17 Figure 1 7 PAL 50 Flat Field Figure 1 8 PAL 100 Flat Field...
Страница 34: ...Specifications 1 20 TSG 95 Service Manual Figure 1 13 PAL Modulated 5 Step Figure 1 14 PAL Multiburst...
Страница 35: ...Specifications TSG 95 Service Manual 1 21 Figure 1 15 PAL Reduced Sweep Figure 1 16 PAL Pluge...
Страница 40: ...Specifications 1 26 TSG 95 Service Manual Figure 1 25 PAL Matrix Signal UK ITS 2...
Страница 41: ...Specifications TSG 95 Service Manual 1 27 Figure 1 26 PAL Safe Area...
Страница 42: ...Specifications 1 28 TSG 95 Service Manual NTSC Waveform Diagrams Figure 1 27 SMPTE NTSC Color Bar Components...
Страница 43: ...Specifications TSG 95 Service Manual 1 29 Figure 1 28 SMPTE NTSC Color Bars Zero Setup...
Страница 45: ...Specifications TSG 95 Service Manual 1 31 Figure 1 31 NTSC Red Field Figure 1 32 NTSC Red Field Zero Setup...
Страница 46: ...Specifications 1 32 TSG 95 Service Manual Figure 1 33 NTSC Sin x x Figure 1 34 NTSC 5 Step Staircase Gray Scale...
Страница 50: ...Specifications 1 36 TSG 95 Service Manual Figure 1 41 NTSC Convergence Components...
Страница 51: ...Specifications TSG 95 Service Manual 1 37 Figure 1 42 NTC7 NTSC Composite Figure 1 43 NTC7 NTSC Combination...
Страница 52: ...Specifications 1 38 TSG 95 Service Manual Figure 1 44 FCC NTSC Composite Figure 1 45 NTSC Cable Multiburst...
Страница 53: ...Specifications TSG 95 Service Manual 1 39 Figure 1 46 NTSC Cable Sweep Figure 1 47 NTSC Matrix...
Страница 54: ...Specifications 1 40 TSG 95 Service Manual Figure 1 48 NTSC Safe Area...
Страница 104: ...Performance Verification and Adjustment Procedures 4 30 TSG 95 Service Manual...
Страница 118: ...Maintenance 5 14 TSG 95 Service Manual...
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Страница 139: ...Replaceable Mechanical Parts 8 5 TSG 95 Service Manual A1 A2 A3 Figure 1 Exploded View...
Страница 140: ...Replaceable Mechanical Parts 8 6 TSG 95 Service Manual...