schematic knowledge

Synchronization circuit to make the signals useful in the process of scanning of the transmitter and sent to the Vertical and Horizontal. To be able to produce images on the picture tube phosphor surface is the same as what was sent, then the necessary adjustments to correct with ualsan which has decomposed on the sender and receiver on the review must be made ​​again, and this is called synchronization.

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On TV transmitter switching pulses that have made ​​the same frequency as in the reviewing, and by using the switching pulse is then mulapenguilasan point getter on the tube and picture tube can be adjusted simultaneously. 

At the transmitter, each end of the line reviews one pulse is emitted horizontally, and also at each end of the line vertical review (this is called a field review), another pulse is emitted. At the receiver using switching pulses had the time of the beginning (start) review can be arranged horizontally and vertically. Switching pulses are called the horizontal synchronizing signal and vertical synchronization.Vertical SynchronizationA. Vertical in the tv series has the following functionsa) bend / open beams of light (information) to the vertical direction.b) Synchronize files from a transmitter in the form of images with short time.

The tool that I made and I discuss in this article I give the name USB SPDIF DACEvery word in the name corresponds to the function of the tool that I made this.

USB, this device serves to take the music information in digital form from a computer via the USB port
SPDIF, this tool can output digital music information received through the USB port, through the SPDIF output terminal that is also present in this device, so if you have a DAC that does not have a USB input, you can still use and do not need to buy a new DAC that has an input USB.
DAC, this tool can convert the digital signals derived from the USB port, an analog signal, which you can connect to the amplifier to the ahirnya you can hear the speaker

As you can see on the schematic in Figure 1 above, which is the heart of the circuit is IC USB DAC PCM2902 made ​​by Texas Instrument, other than that I also added a digital SPDIF output isolation transformer on from this series. 2902 PCM encoding decoding work on the principle that generally abbreviated as word CODEC. 

The new circuit will work when the USB input port terminal in the circuit connected to the computer, at this voltage 5V on the USB port of any computer will be triggering the circuit to begin work, and vice versa when the computer is turned off then the circuit will be in standby mode to wait until there is more tension 5V from USB port of computer. 

When the received voltage is 5V USB port the computer then the circuit will begin to receive the digital data files during the grace period of 1 ms, all data received during the period of time of 1 ms is called a frame, the data in the first frame is stored in a memory buffer that is in the PCM2902, then the circuit will start the second frame as well as long lead times for 1mS, 1mS a second after the first data from the file will be converted into analog signals for analog terminal is then removed through out the pin 15 and 16 of the PCM2902, other than that this digital signal simultaneously will also excreted through the DOUT terminal pin 25 of the PCM2902 DAC to be connected to older products that do not have a USB input terminal.In addition to functioning as a DAC, PCM2902 actually also has other functions such as setting volume level and ADC, but the circuit that I developed is only aimed for the ADC and the conversion from USB to SPDIF.

Power Supply that I use in this project using the configuration has been proven able to tame the hum in the tube 26, the power supply has karakater very stable, low noise and low impedance, but complicated to make, so for the purposes of this project I recommend another series that is not as complicated Heater power supply 26, but the quality is still better than most of the power supply kit used in the DAC in general, Figure 2 below is the recommendation power supply for USB DAC this project.

 4. BD139 transistor as a pass transistorThis configuration is basically the general configuration of a linear regulator series, very much the regulator IC using this configuration, but the circuit in Figure 2 above has several advantages that are not owned by the regulator circuit in the form of ICa) high stability, since it uses a reference voltage source of good quality is TL431, and therefore not in a package with a pass transistor, the heat of the pass transistor can not seep into the source of reference voltage and makes it unstable, this sort of thing happens in IC voltage regulator.b) Using the Op Amp high quality, which in this case OP27, so it is not easy to oscillate as the OpAmp used in the regulator IC.c) If there is a chance you could also replace the TL431 or OP27 Op Amp voltage source and another that is expected to be better than either of these components.

RF power amplifier IC is a type of electronic amplifier used to convert low-power radio frequency signal into a larger signal strength is important, usually for driving a transmitting antenna. This is usually optimized for high-efficiency, high output power (P1dB) of compression, loss of income on the input and output, better benefits, and optimal heat dissipation.

To make our amplifiers can also use transistors or IC OP Amp. In the op amp is actually a transistor that is in the form of a series so its easier to use.

Suppose that is used in the amplifier IC Op Amp 741 is a monolithic high performance electronic components that use Fairchild epitacial process. IC Op Amp 741 is an IC in which packed a differential circuit. The data sheet of IC Op Amp 741.

This is a circuit for touch switch circuit. This circuit is almost same with touch door alarm. This circuit uses a 555 timer as the bases of the touch switch circuit. This is the figure of the circuit.


The operation of this circuit is begin, when the plate is touched the 555 timer is triggered and the output on pin 3 goes high turning on the LED and the buzzer for a certain period of time. The time that the LED and the buzzer is on is based on the values of the capacitor and resistor connected to pin 6 & 7. The 10 M resistor is on pin 2 causes the circuit to be very sensitive to the touch.

This stepper controller circuit shown here can used to control the unipolar stepper motor,which has 4 coils . The stepper controller circuit can drive for a motor current of up to about 500 mAmp/Winding by suitable heat sinks for the SL-100. directsinks In higher currents power transistors seem 2N3055 can be used as darlington pair along with SL-100. All diodes are used to protect back current the transistor from transients.

Stepper Motor Circuit with IC 4027 Circuit diagram :



Remark. 

• You may be able to substitute any standard (2N3055) power transistor for Q1-Q4 or get IC type UL to modify for transistor.
• Every time in move the motor put signal the STEP line is pulsed, the motor moves one step.
• Switch S1 for changes the motors direction