A straight-line stairwell elevator, a curved orbital elevator, a ramp lift in hyonan district

The ramped and accessible wheelchair lift platform is controlled mainly by plc and the variable frequency switcher. Plc collects information and processes it then issues instructions, and the fm controls the motor's operating machine speed in accordance with the plc directive。

PlcRationale

Programmable controller, called programmable logiccontroller, known as plc. Plc is a computer-based electronic controller and applies to industrial field work. It originates from a relay control device, but it is not controlled through the physical process of the circuit, as is the case with a relay device, but is controlled mainly by the operation of a program stored in the plc memory for the conversion of incoming and outgoing information。

Plc uses the "scanning in sequence, revolving" mode of work

1. Each scanning process concentrates on collecting input signals and on updating the output signals。

2. Enter a refreshing process whereby, when the input port is closed, the application has a new state at the input end that cannot be read into. Only when the program is next scanned will the new state be read in。

A scanning cycle is divided into input sampling, program execution, output refreshing。

4. The content of the widget image register changes as the procedure is carried out。

The length of the scanning cycle is determined by three rules。

(1) speed of cpu implementation

(2) time of possession of the directive itself

(3) the plc scans are now very fast。

 The principles of the variable frequency modem

The main circuit is the electrical transformation component that provides a voltage-adjusted fm power source for the different motors, and the main circuit for the transformers can be broadly divided into two categories: the voltage type is the conversion of the current flow of the power source into a convulsive variant, and the filter for the flow-back path is the electrical capacity. The current type is the conversion of the current from the current source to the interactive transient, and the direct flow-back filter is the electrical sense. It consists of three components, which convert the industrial frequency power source to a "resolver" of direct current power, a "square wave loop" absorbing electrical pulses generated by transformers and reversers, and a "reverse" of direct current power to communicate power。

Fluorator

Recently, there has been extensive use of diode transformers, which convert industrial frequency power to a direct current. Two sets of transistor transformers may also be used to form reversible transformers, which, because of their reversible power orientation, can be regenerated。

Pingbo returns

In direct current voltage after the current of the integrator, the pulsation voltage with a power of six times the frequency, in addition to the pulsive voltage generated by the reverser, which causes the direct current voltage to change. In order to contain voltage fluctuations, electrons are used to absorb pulsive voltage (electric currents) with electric senses and capacitation. Installation capacity hours, where there is a surplus of power and main circuit components, a simple flat-wave circuit can be avoided。

Reverser

In contrast to the inverters, the reverse is the conversion of the direct flow power to the communication power required by the required frequency, so that the six switches will have a 3-way exchange output at the specified time. An example of switch time and voltage wave shape is a voltage pwm reverser。

Control the circuit

It is a circuit that provides a control signal to the main circuit that provides power (voltage, frequency modifiable) to the different motors. It consists of a “calculated circuit” of frequencies, voltage, current detection circuits of the main circuits, “velocity detection circuits”, “driving circuits” that amplifies the control signals of the circuits and “protected circuits” of reversers and electric motors。

(1) calculating circuits: comparing external velocity, rectangular commands with current, voltage signals for detecting circuits, and determining the output voltage, frequency of reversers。

(2) voltage, current detection circuits: separation from main circuit level detection voltage, current, etc。

(3) driven circuit: drive the circuit of the main circuit device. It is isolated from the control circuit, which leads to the main circuit device being shut down。

(4) speed detection circuits: the velocity signal is a velocity signal from a velocity detector installed on the axle of the arctic motor, and is sent into the calculator circuit, which, according to the instructions and calculations, allows the electrical motor to operate at the command speed。

(5) protection of circuits: detection of electrical voltage, currents, etc. Of the main circuit, in order to prevent damage to reversers and differentiating motors, in case of abnormalities such as carrying or passing voltage, to stop the retroverts from working or to inhibit voltage, current values。