1, STB 5V circuit details
Exchange electric into power Board component Shi, after anti-waves Chung circuit, filter except bad of miscellaneous spread interference Hou, directly sent to has BD2 (G3SBA60), and C100 (450V/22uF) composition of Deputy power rectifier filtering circuit, produced near 300V of pulsating DC voltage, into STB 5V switch transformer T3S (BCK50-T3SDI) of 1 feet, and 2 feet winding, again to IC2 (ICE2A280Z) of 5 feet; C100 (450V/ 22uF) 300V pulsating DC voltage on the anode, and R67 (180K/1W), R68 (180K/1W) started two resistors, IC2 (ICE2A280Z) to provide initial power to the 7 foot, IC2 (ICE2A280Z) began to work the T3S (BCK50-T3SDI) each of windings is induced voltages 10 pin and 7-foot winding induced voltages produced by by the D28 (D2S6M) rectifier C39 (10V/2200uF) filter and then through L6 (7uH), C40 (50V/47uF), п-shaped filter consisting of obtaining stable 5V DC voltage that STB 5V voltage. But T3S (BCK50-T3SDI) of the induced voltage between 3 foot, 4 foot, take the D27 (BYV38), Rectifier, C50 (50V/47uF) filter into IC2 (ICE2A280Z) of 7 feet, to take the IC2 (ICE2A280Z) to provide normal power supply, STB 5V power supply was working properly. VR2 (1K) and IC6 (KA431AZ), OU PC3S (TLP421), and IC2 (ICE2A280Z) 2nd leg form the STB and 5V voltage regulator circuit, adjust VR2 size STB 5V voltage can be adjusted.
(BCK50-T3SDI) 5-foot, 8-foot winding output ripple voltage, the D25 (BYV38), Rectifier, C38 (50V/47uF) filter is getting voltage, voltage output as VCC-S on the one hand, on the other hand sent to Q14 (IRFU9120) electronic switching. Q14 (IRFU9120) electronic switch PS-ON off and signal control, but PS-ON for low level light OU PC9 (TLP421) light emitting diode conduction within the subprime phototransistor breakover, Q14 (IRFU9120) electronic switch breakover, take the D25 (BYV38), Rectifier, C38 (50V/ 47uF) filter is getting voltage Q14 (IRFU9120) send electronic switch to IC8 (KA7818) IC8 (KA7818) the VC-S-R voltage regulator get 18V, the output to the IC7 (KA1M0880B), IC31 (KA317) circuit, IC7 (KA1M0880B), IC31 (KA317) operating voltage (see Figure 1).
IC8 (KA7818) the VC-S-R voltage regulator get 18V and then by Q11 (IRFU9120) VC-S-F voltage switches to get around 17V. VC-S-F voltage provided to the IC35 (KA1M0880B) to provide the operating voltage. VC-S-F voltage provided to Q13 (C2383), RL3S relays controlled 220V AC input voltage to rectifier-filter circuits are controlled.
(ICE2A280Z) is a switching power supply control IC with MOS pipes, pins of its main functions are as follows:
1 foot is decoupled (filtering) foot, capacitor;
2 feet is regulated, and foot protection and control;
Internal earth terminal MOS tube 3 feet and over current protection;
4 foot, 6 foot empty legs
Feet for 300V voltage input
7 pin power feet;
8 foot grounding feet.
2, PFC workflow
When the power control circuit or power supply Board of the TV system during the self-test, PS-ON control signal is converted to a low level, Q14 (IRFU9120) electronic switch breakover, IC8 (KA7818) the VC-S-R voltage regulator get 17V, and then by the Q11 (IRFU9120) voltage regulator be VC-S-F voltage of about 12V. Q13 VC-S-F voltage (C2383) reached the RL3S relay. RL3S relay closed. 220V AC by RL3S relay find main rectifier bridge BD1 (D15XB60), BD3 (D15XB60), Rectifier, D9 and PFC diode (UF5408) and PFC inductor L1, D10 (RHFP1560) C5 (450V/330uF), C6 (450V/330uF) measurements. Q1 (SPW47N60S5), Q2 (SPW47N60S5) is the PFC transistor, Q3 (KSP2222A) and Q4 (KSP2307A), drive control, and Q3 (KSP2222A) and Q4 (KSP2307A) and PFC control circuit IC1 (ML4824IP1) of the 12th foot control output PFC incentive-driven. In the role of PFC circuit control and on C5 (450V/330uF), C6 (450V/330uF) on the cathode will be B+ PFC voltage 380V, sent to each element of the circuit for DC-DC conversion.
3, VA voltage circuit details
Unit circuit is mainly composed of the IC35 (KA1M0880B) and the T8S (B4K50-T8S), PC12S (TLP421), IC36 (KA431AZ) circuit. B + voltage PFC T8S (B4K50-T8S) of 1 foot, 2 feet of winding, to the IC35 (KA1M0880B) of 1 foot, from Q11 (IRFU9120) switches to get around 17V VC-S-F voltage to the IC35 (KA1M0880B) of the 3rd foot, giving the IC35 (KA1M0880B) provide operating voltage The IC35 (KA1M0880B) and the T8S (B4K50-T8S) began work, in T8S (B4K50-T8S) switching transformer secondary 8 feet, 11 feet to 14 feet 10 feet between the windings of the ripple voltage, the D37 (KCF16A60) rectifier, C571 (100V/100uF), C57 (100V/100uF), L5, C58 (100V/100uF), C59 (100V/ 100uF) filter, get 79V VA voltage, addressing circuit component output to the screen to screen the addressing circuitry provides the power.
(150K), R297 (3.3K), VR7 (2K) voltage obtained reference voltage sent to IC36 (KA431AZ), IC36 (KA431AZ) through the R292 (4.7K), R293 (1K), controlling the optical coupling PC12S (TLP421AZ) sub-degree breakover, PC12S (TLP421) and the degree of conduction of the internal primary phototransistor secondary synchronization, PC12S (TLP421) primary a phototransistor is connected to the IC35 (KA1M0880B) and 4 feet. Changing the IC35 (KA1M0880B) 4 foot level can change the internal drive pulse waveform of cycle and to realize the IC35 (KA1M0880B) internal switch cycle the control tubes to control switching power supply's output voltage. Adjust VR7 (2K) variable resistors resistance value can be changed by R295 (150K), R297 (3.3K), VR7 (2K) the voltage divider network scores and, ultimately, by IC36 (KA431AZ), the R292 (4.7K), R293 (1K), PC12S (TLP421) for the IC35 (KA1M0880B) 4 foot-level control In order to achieve the T8S (B4K50-T8S) VA secondary output voltage control.
(KA1M0880B), Samsung produced a novel switching power supply control for thick film integrated circuits, each function is as follows:
① feet: thick-film IC built-in switch drain;
Second leg: thick-film IC built-in switch source and grounding;
③ feet: thick-film IC power foot, and over-voltage, under-voltage protection circuit testing apex. When the initial power supply 15V, thick-film IC will not start protection, subsequent thick film integrated circuit voltage drops below 10V will not start and protection. But in this power, all offering up to 17V of VC-S-F voltage, so the thick-film IC's overvoltage, undervoltage protection circuit is not being used;
④ feet: thick-film IC error signal input pin, also known as conduction control foot pin voltage must be no higher than 7.6V, or thick-film IC internal comparator to shutdown the output signal, the power supply will stop working;
⑤ feet: sync pulse input pin.
4, VSCAN voltage circuit details
Voltage is converted by the VA voltage DC-DC converter circuit, only VA voltage normal, can guarantee the VSCAN voltage normally.
Voltage sent to T7S (B4K50-T7S) switching transformer of 1 foot, then by a switching transformer 2 feet to IC18 (KA1L0380R) of 2 feet. VA voltage through starting resistor R207 (47K/3W) IC18 (KA1L0380R), 3rd foot power. R153 (100K), C199 (1nF) D48 (BYV38) absorbed by spikes, protect IC18 (KAIL0380R) of the internal switch.
(KA1L0380R) started working, output ripple voltage of the winding, 3 foot, 4 foot winding
Output ripple voltage, D199 (BYV38), Rectifier, C95 (50V/47uF) filter, IC18 (KA1L0380R), 3rd foot provides the normal operating voltage, T7S (B4K50-T7S) switch between 4 feet and 7 feet of winding of the transformer output ripple voltage, via the D49 (BYV27-600) rectifier, C107 (100V/100uF) filter, output VSCAN voltage of 78V.
(B4K50-T7S) of 5 feet, 6 feet, a winding output voltage, take the D151 (BYV38), Rectifier, C201 (47uF) filter to get a DC voltage provided to the optical coupling PC6 (TLP421) as well as the IC21 (KA431AZ). Optical coupling PC6 (TLP421) and IC18 (KA1L0380R) composed of the 4th foot and VSCAN voltage regulator circuit. R271 (51K), R272 (62K), R273 (3.3K), the VR6 (2K) formed the VSCAN voltage voltage sampling circuit, resize the VR6 VSCAN voltages can be adjusted. By R271 (51K), and R272 (62K), and R273 (3.3K), and VR6 (2K) composition of sampling circuit sampling get of feedback, sent to three end benchmark regulator IC IC21 (KA431AZ), IC21 (KA431AZ) control light OU PC6 (TLP421) secondary internal glow diode of guide pass, led to light OU PC6 (TLP421) of primary of guide pass situation also occurred changes, Transforming IC18 (KA1L0380R) pin 4 voltage, IC18 (KA1L0380R) 4 feet is voltage adjustment pin, the PIN voltage changes will cause changes in the internal switch's breakover time to realize switching power supply output voltage changes, and thus the VSCAN voltage adjustment.
Samsung produced a novel switching power supply control for thick film integrated circuits, each function is as follows:
① Earth Terminal;
②, thick-film IC built-in switch drain;
③ thick-film IC power foot, and over-voltage, under-voltage protection circuits detect apex;
Black, thick-film IC error signal input pin, also known as conduction control feet.
5, VS voltage circuit details
VS voltage in plasma screens belonging to the primary voltage, high voltage, high current, so using two parallel output of the switching transformer design, in order to achieve power supply internal resistance is smaller, ripple effect.
VS voltage is mainly to IC30 (IR2109) and Q6 (K2372), Q8 (K2372), T1S (BCK50-T1S) and T2S (BCK50-T2S) circuit consisting of. By T1S (BCK50-T1S) and T2S (BCK50-T2S) two identical parallel output of switch transformer to make VS minimal internal resistance of the power supply, and can provide the maximum current.
When the circuit was working properly, and b + voltage PFC directly to Q6 (K2372), VC-S-R voltage 18V IC31 (KA317) produce a 12V voltage regulator, sent to IC30 (IR2109) 1 foot to IC30 (IR2109) power supply, while VC-S-R voltage or resistance of R250 (300), R62 (300) to PFC main controlled circuit IC1 (ML4824IP1) of 13 feet provides work power, IC1 (ML4824IP1) began work, in 11 feet output a pulse wide modulation incentive control signal to of 2 feet, IC30 (IR2109) began work, in 5 feet, and 6 feet, and 7 feet pour phase output control signal, respectively control Q6 (K2372), and Q8 (K2372) switch tube began work, in T1S (BCK50-T1S), and T2S (BCK50-T2S) switch on the transformer voltage mutual inductance, its secondary transformer voltage via the D41 (KCF16A60), D42 (KCF16A60) parallel connection rectifying, C26 (200V/1200uF), C27 (200V/1200uF) filter, get 87V VS voltage.
R87 (200K), R92, (5.1K), VR1 (2K), IC5 (KA431AZ), PC1S (TLP421) and PFC circuit IC1 (ML4824IP1) 6 foot form the VS voltage regulator circuit. Dang change VR1 (2K) can adjustable resistance of resistance Shi, through three end regulator benchmark circuit IC5 (KA431AZ), change light OU PC1S (TLP421) of secondary internal glow diode of guide pass degree, thus through light OU PC1S (TLP421) of primary, change has PFC control circuit IC1 (ML4824IP1) 6 feet of voltage, PFC control circuit IC1 (ML4824IP1) 11 feet output of pulse wide modulation