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Daewoo DSC-3220E/3220L service manual

Models: DSC-3220E/3220L

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Service manual SC-150

5-2-5 Video Demodulation and Amplifier

The video IF signal, which is applied from the gain controlled IF amplifier, is multiplied with the in-phase component of the VCO signal. The video demodulator is designed for low distortion and large bandwidth. The demodulator output signal passes an integrated low pass filter for attenuation of the residual vision carrier and is fed to the video amplifier. The video amplifier is realised by an operational amplifier with internal feedback and 8 MHz bandwidth (–3 dB). A standard dependent dc level shift in this stage delivers the same sync. level for positive and negative modulation. An additional noise clipping is provided. The video signal is fed to VIF-AGC and to the video output buffer. This amplifier with a 6 dB gain offers easy adaptation of the sound trap. For nominal video IF modulation the video output signal at Pin 12 is 2 Vpp.

5-2-6 Sound IF Amplifier and SIF-AGC

The SIF amplifier is nearly identical with the 3-stage VIF amplifier. Only the first amplifier stage exists twice and is switchable by a control voltage at Pin 3. Therefore with minimal external expense it is possible to switch between two different SAW filters. Both SIF inputs features excellent cross-talk attenuation and an input impedance which is independent from the switching condition. The SIF-AGC is related to the average level of AM- or FM-carrier and controls the SIF amplifier to provide a constant SIF signal to the AM demodulator and QPS mixer.

5-2-7 Quasi-Parallel-Sound (QPS) Mixer

The QPS mixer is realised by a multiplier. The SIF signal (FM or NICAM carrier) is converted to the intercarrier frequency by the regenerated picture carrier (quadrature signal) which is provided from the VCO. The intercarrier signal is fed via an output amplifier to Pin 24.

5-2-8 Standard Switch

To have equal polarity of the video output signal the polarity can be switched in the demodulation stage in accordance with the TV standard. Additionally a standard dependent dc level shift in the video amplifier delivers the same sync. level. In parallel to this, the correct VIF-AGC is selected for positive or negative modulated VIF signals. In the case of negative modulation (e.g., B/G standard) the AM output signal is switched off. For positive modulation (L standard) the AM demodulator and QPS mixer is active. This condition allows a parallel operation of the AM sound signal and the NICAM-L stereo sound.

5-2-9 L’ Switch

With a control voltage at Pin 14 the VCO frequency can be switched for setting to the required L’ value (L’ standard). Also a fine adjustment of the L’-VCO center frequency is possible via a potentiometer. The L’ switch is only active for positive modulated video IF-signals (standard switch in L mode).

5-2-10 Internal Voltage Stabiliser

The internal bandgap reference ensures constant performance independent of supply voltage and temperature.

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Daewoo DSC-3220E/3220L service manual
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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.