Modulating signals of transmission stations to reception stations is a key factor to
guarantee the best possible transmission and reception of these signals .Digital modulation
represents a huge evolution in communication field and modulation, whic
h used to depend
on analog signal modulation of one parameter-Amplitude . frequency or phase.
Digital modulation depends on transforming the transmitted data signal (Bits) and then
sending it as samples, and changed back into an analog signals in reception station .
In digital systems, digital data are transformed into analog data in the transmitter and does
the reverse in the receiver. In digital transmission, on the other hand, as in wired local area
networks (WLAN), Digital data are transmitted in their digital state.
التعديل النبضي المرمز
تعديل عرض النبضة
تعديل مطال النبضة
تعديل موقع النبضة
إشارة المعلومات
مبدل تشابهي إلى رقمي
مبدل رقمي إلى تشابهي
PCM ( Pulse Coded Modulation )
(PWM (Pulse Width Modulation
PAM (Pulse Amplitude Modulation)
PPM (Pulse position modulation)
Audio Signal
A/D (Analog to Digital Convertor)
D/A ( Digital to Analog Convertor)
المزيد..
In this paper, the development of the drive system of the motor Wire port Crane
according to the principle of the indirect field orientation.
Require the operation of the port Crane operations, different operation situations of
variable speed and
Torque with time, which is a case dynamic electro and electro-magnetic
transient, may affect the performance of operations, so therefore been building motor Wire
port Crane operations system corps in winches achieve:
- High performance and Efficiency.
- Build the desired control system according to the principle of the Pulse Width
Modulation (PWM) and the main power system, taking into account the reduction of
changes DC-Link voltage and achieve maximum flux before starting the motor.
- Reduction of excess Voltage that may appear on a DC-Link, using the brake
Transistor with Brake resisters.
At the end of the research has been reviewed and the search results that indicate the
outstanding performance of the proposed system with the ability to use the same system to
run automated processes different.