Daewoo DSC-3220E/3220L service manual Overcurrent protection function OCP, Latch circuit

Page 63

Service manual SC-150

When the MOSFET is ON, the STR-F6654 internal capacitor C1 is charged at the constant voltage 6.5V.

At the same time, the voltage at pin 1 (OCP / FB) increases with the same waveform as the MOSFET drain current.

When the pin 1 voltage reaches the threshold voltage VTH1 = 0.73V, the STR-F6654 internal comparator 1 starts operating. The STR-F6654 internal oscillator is inverted and the MOSFET turns OFF.

When the MOSFET turns OFF, charging of STR-F6654 internal capacitor C1 is released and C1 starts discharging by the STR-F6654 internal resistance R1. So, C1 voltage starts falling in accordance with the gradient regulated by the constant discharging time of C1 and R1. So, this means that the fixed time determined by C1 and R1 is the OFF-time of the MOSFET.

When C1 voltage falls to around 3.7V, the STR-F6654 internal oscillator is reversed again and the MOSFET turns ON. C1 is quickly charged to around 6.5V

The MOSFET continues to oscillate by repeating the above procedure.

5-9-2-3 STR-F6654 protection circuits

overcurrent protection function (OCP)

Overcurrent protection is performed pulse by pulse detecting at STR-F6654 pin 1 (OCP) the peak of the MOSFET drain current in every pulse.

• latch circuit

This circuit sustains an output low from the STR-F6654 internal oscillator and stops operation of the power supply when overvoltage protection (OVP) and thermal shutdown (TSD) circuit are under operation

thermal shutdown circuit (TSD)

This circuit triggers the latch circuit when the frame temperature of STR-F6654 IC exceeds 140° C

overvoltage protection circuit (OVP)

This circuit triggers the latch circuit when the Vin voltage exceeds 22V (typ.)

-62-

Page 62 Page 64
Image 63
Page 62 Page 64
Contents Chassis SC-150 Contents General description Main PCB Union PCB Tuning system Main FeaturesPower consumption Sound Output PowerSvhs Pin Signal Description Matching value Page C04 C01C02 C03639.25 S13 S10S11 S12Special case Country selection = Others Program Group SkipITV RAY Radiation Precaution Safety instructionHOR Width Order Default settingh for SC-150Alignment instructions ParabolaOption HOR Paral BOW HOR Width Corner EW Trapez VCT IC descriptionPage Page IC version VCT 3832A VCT 3834A Chassis IC marking OSD languages Atss countries TextPin Name Type Short Description Gndaf Supply AGC Page German 2-Carrier System Dual FM System DSP-Section Audio Baseband ProcessingAnalogue Section Nicam plus FM/AM-MonoAdrsel PALSECAM-L UssrVREF2 ResetqDvsup DvssXtalin FeaturesANAIN1 TestenPin Symbol Function Mode OUT1GND1 OUT1+TDA8946J Page GND Block diagram TDA6107Q SCL SDAPage TJ TSD Pin Name Symbol DescriptionVIN OVP IIN HDescription IC Pins Symbol Rating Unit I2C Decoder SW3 SW1SW0 SW2IN2 IN3OUT IN1VEE Circuit description If section Block diagram Vision if Amplifier FPLL, VCO and AFC Standard FeaturesPage Page Adaptive Comb Filter VCT3834A only Video Sync Processing CRT Measurement and Control Page Stand by ConfigurationDescription Application Forced KEY Page Quadrature Mixers ESCPage Page STR-F6654 general description Power supply primary part operationsPage STR-F6654 oscillating operation Overvoltage protection circuit OVP Overcurrent protection function OCPLatch circuit Thermal shutdown circuit TSDTV start-up operations TV normal run and stand-by mode operations Page FBT SC-150 Controlled Rectifier 6V DC High Service Parts List Cord Power Oxide Film 2W 1.2 OHM J Small Semi Fixed CCZB1H561K Cera Carbon Film Metal Film Carbon Comp PA01A RF27 RD-4Z221J Jumper Different Part List by PCB & Micom Version Main PCBUnion PCB Jumper DELExplode View PCB Main PCB Union Schematic DiagramMAIN Schematic DiagramUNION

DSC-3220E/3220L specifications

The Daewoo DSC-3220E/3220L is a noteworthy addition to the lineup of high-efficiency air conditioning solutions, specifically crafted to meet the demands of varying climatic conditions. With a blend of innovative technologies and robust design, these models stand out in the realm of home and commercial air conditioning.

One of the main features of the DSC-3220E/3220L is its efficient cooling performance. The units are built with advanced rotary compressors, which are designed to operate efficiently while providing powerful cooling capabilities. This allows for quick temperature adjustments, making it an ideal choice for those who seek rapid relief from heat.

Another remarkable aspect of the DSC-3220E/3220L is its energy-efficient operation. With a superior Energy Efficiency Ratio (EER), these air conditioning units ensure that energy consumption is minimized without compromising comfort. This not only reduces electricity bills but also contributes to a smaller carbon footprint, making it an environmentally friendly choice.

The units also come equipped with state-of-the-art air filtration technologies. The multi-layer air filters are designed to capture dust, pollen, and other airborne particles, ensuring that the air in the environment remains clean and healthy. This feature is particularly beneficial for allergy sufferers and enhances the overall indoor air quality.

In terms of user convenience, the DSC-3220E/3220L models are engineered with user-friendly controls. Many features, including temperature settings and fan speeds, can be easily adjusted through a remote control or a digital display panel on the unit itself. This ensures that users can customize their comfort levels with minimal effort.

Noise reduction is another critical characteristic of the DSC-3220E/3220L. Both models are designed with silent operation in mind, making them suitable for bedrooms, offices, and other environments where noise can be a distraction. The sound insulation techniques employed help maintain a serene atmosphere while enjoying optimal cooling.

Furthermore, installation of the DSC-3220E/3220L air conditioning systems is straightforward, making them accessible for residential and commercial settings alike. The compact design and versatility in installation options allow these units to fit seamlessly into various spaces without sacrificing performance.

Overall, the Daewoo DSC-3220E/3220L embodies a fine balance of efficiency, technology, and user-centric design, making it a commendable choice for air conditioning needs in diverse settings. With its reliable performance and thoughtful features, it continues to gain popularity among consumers looking for effective climate solutions.
Top Page Image Contents