جهاز التحكم الكمبيوتري (Quasar) ذو الضواغط .. كتاب التلفزيون الملون والعادي

19-6 Quasar computer control unit for compressors:

This device is ideal for demonstrating synthetic frequency tuning. It consists of two parts. The first is the mobile remote control that the viewer uses to perform all operations of controlling the TV. The other part is the fixed part of the TV that receives and executes the control instructions.

The working principle of the receiver controller in the device:

The viewer can choose to tune directly to the desired station or search for it.

In the first selection, the viewer enters the desired station number on the keypad, in any order desired - and the desired station number appears on the display
​Small at the top of the device, which accommodates only two digits, using LED elements, ie
Light emitting diodes.

When requesting any station, two numbers must be entered. If we want to tune the station to channel (2), then two numbers (02) must be entered. The first represents the number of ones and the second represents the number of tens.

If we entered the first number only and did not enter the second number within 3-4 seconds after that, the device will remain on the original channel, and the display screen will return to the original station number again.

If we ask for a channel number, and there is no broadcasting station on it, and the SEEK switch is in the ON position, the device tunes in to the next channels that are in the broadcasting position. The viewer can press the (Channel) button to choose the channel with the highest number, and press the (Channel down) button to choose the channel with the lowest number... Then the device works automatically to search for the next working station. If the channel selection presses are pressed during the search time, the last number may be stored in the memory, causing the failure of the subsequent channel selection process. If this happens, press the number 5 zero. Then the device tunes in the station, after which two numbers can be entered for the desired station.

How the remote control works:

This device works by emitting infrared rays. It contains several pistons (or compressors). As shown in the figure, the first pusher controls turning the device on or off (ON-OFF), as well as the volume (Volume) with three positions, and a pusher for selecting channels in two positions (Channelup) with three positions. And a pusher to select channels in two modes (Channelup) for the upper channel and (Channeldown) for the lower channel. There are some devices that have numbers to choose the tuned station directly.

Device operating modes:

There are three operating processes and this is an explanation for them:

1- (Seek off Fine Tune Normal) Canceling the function of searching and tuning on the channel whose number we enter, and staying on that channel whether it has a station that broadcasts first. Thus, the voter can be tuned on an empty channel to use the video equipment (VTR), video game console, or during fault repair work Or if you want to fine-tune manually.

​2 - (Sekon, Fine Tune Nomal )
Turn on the search function and fine tuning
Natural.

In this mode, the station can be tuned by digital input or by pressing (Channel up) or (Channel down). If there is no working station broadcasting in the required channel, the device operates the function of searching for fine tuning, and sensing the signal indicating the presence of the working station. Then the tuning remains to pick up this station - but if it does not sense the presence of a working station, it moves automatically to the next channel until it picks up a broadcasting station, and this station can be fine-tuned manually.

3 - See on Automatic Fine Tune Turn on the search function - fine tuning is done automatically, and this is similar to function / 2 / except for fine tuning, which is done automatically. It compensates for the displacement of the image carrier, which may shift by (10 kilohertz) in the opposite direction in the event that there are two adjacent stations and there is fear of their interference, especially in the VHF field.

Fine tuning compressors:

A fine tuning key is not usually necessary. Because the voter is precisely tuned to the specified channel frequency. However, it is equipped with compressors for fine tuning, to avoid some abnormal signal conditions and interference, and to tune video, game and some special stations. The key is pressurized. If there is an overlap in colors, sound or image, it turns on the first key for fine tuning. Then we keep pressing the other key until the required tuning is done. The device returns to the exact channel frequency when the same or other channel number is entered

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