Electrician exam positive and negative circuit diagram and connection diagram
The following are the principles of the motor positive and negative circuit diagrams and connection diagrams involved in several common electrical examinations: ** I. Contactor interlocked motor reversing control circuit ** 1. ** Principle ** - Forward rotation control: Turn on the power switch Q, press the forward start button SSB2, and the coil of the contactors KM1 will be energized and pulled in. At this time, the main contact is closed to connect the motor to the power supply, and the normally open auxiliary contact is closed to realize self-locking (even if the SSB2 button is released, the KM1 coil is still energized). The motor M is rotating in the forward direction. At the same time, the normally closed auxiliary contact of the KM1 was disconnected, which prevented the power supply of the contactors KM2 (realizing the interlocked, preventing the two contactors from being energized at the same time and causing short-circuit and other faults). At this time, the phase sequence of the power supply connected to the motor was A-B- C. - Reverse rotation control: If you want the motor to change from forward rotation to reverse rotation, first press the stop button SSB1, so that the forward rotation circuit is cut off (the KM1 coil loses power, the main contact is cut off, the normally open auxiliary contact is cut off, and the normally closed auxiliary contact is restored to be closed), and then press the reverse start button SSB3. The KM2 coil is energized and attracted, and its main contact and the normally open auxiliary contact are closed, so that the motor can rotate in reverse. At the same time, the normally closed auxiliary contact of KM2 was disconnected to prevent the contact KM1 from being energized. At this time, the phase sequence of the power supply connected to the motor was C-B- A. To stop the electric motor, press the stop button SSB1. 2. ** Connection diagram key points (illustration)** - The main circuit part: the three-phase power supply is connected to the fuse (for protection), then connected to the main contacts of the contactors KM1 and KM2, then connected to the thermal relay (for overload protection), and finally connected to the motor. Among them, the main contact connection of KM1 and KM2 must ensure the correct switching of phase sequence during forward and reverse rotation. - The control circuit part: connect the stop button SSB1 (normally closed contact) from the power lead. The other end of SSB1 is connected to the forward start button SSB2 (normally open contact) and the reverse start button SSB3 (normally open contact) respectively. The other end of the SSB2 is connected to the coil of the contactors KM1, and the normally closed auxiliary contact of the KM2 is connected in series on this line to realize the interlocked connection; the other end of the SSB3 is connected to the coil of the contactors KM2, and the normally closed auxiliary contact of the KM1 is connected in series on this line to realize the interlocked connection. The normally open auxiliary contacts of the contactors KM1 and KM2 are respectively connected in parallel with their respective start buttons to realize the self-locking function. ** 2. Double interlocked reversing circuit ** 1. ** Principle ** - This circuit combined a button interlocked with a contactors interlocked. The button interlocked was achieved through the circuit design of the forward start button SSB2 and the reverse start button SSB3, and the contactors interlocked through the normally closed auxiliary contacts of KM1 and KM2. The advantage of this design was that it could directly switch the direction of the motor, which improved the convenience and safety of the operation. 2. ** Connection diagram key points (illustration)** - The main circuit is similar to the control circuit of the positive and negative rotation of the interlocked motor. - Control circuit part: on the basis of the interlocked contactors, the normally closed contacts of the forward start button SSB2 and the reverse start button SSB3 are respectively connected in series to the starting circuit of the other party to achieve button interlocked. For example, the normally closed contact of the SSB2 is connected in series in the circuit connecting the SSB3 and the KM2 coil, and the normally closed contact of the SSB3 is connected in series in the circuit connecting the SSB2 and the KM1 coil. ** 3. Automatic shuttle control circuit (an application of the motor's forward and backward rotation)** 1. ** Principle ** - After switching on the power switch QL, press the start button (similar to the forward start button), the contactors KM1 will self-lock, and the trolley will start to move forward. When the limit switch SQ1 was touched, the KM1 coil lost power, the KM2 self-locked, and the trolley ran in the opposite direction. As long as the stop button was not pressed, it would cycle. 2. ** Connection diagram key points (illustration)** - The main circuit part was also a three-phase power supply to the motor through the fuse, the main contact of the contactors, and the thermal relay. - Control circuit part: In addition to the control circuit of the positive and reverse contactors KM1 and KM2 (including interlocked), it also needs to be connected to the travel switch SQ1 and SQ2 (used to control the positive and reverse limits respectively). For example, in the forward operation, the KM1 self-locking circuit is connected in series with SQ2 (normally closed contact). When the trolley touches SQ2, the KM1 coil loses power; in the reverse operation, the KM2 self-locking circuit is connected in series with SQ1 (normally closed contact). When the trolley touches SQ1, the KM2 coil loses power. Read more exciting novels for free
Diagram of Positive and Negative Rotation Circuit for Electrician Operation
The circuit diagram of the motor consists of two parts: the main circuit and the control circuit. Principle of the main circuit: After the three-phase power supply passes through the fuse, it is divided into two paths to the main contacts of the two contactors. The phase sequence of the main contacts of the contactors corresponds to the power supply. The main contacts of the two contactors were connected in parallel after being swapped, then connected to the thermal relay, and finally connected to the motor. For example, when the KM1 main contact is connected, the power supplies L1, L2, and L3 flow to the first phase, the second phase, and the third phase of the three-phase motor respectively, and the motor is rotated in the forward direction; when the KM2 main contact is connected, the power supplies L1, L2, and L3 flow to the third phase, the second phase, and the first phase of the three-phase motor respectively, and the motor is rotated in the reverse direction. By controlling the main contacts of the contactors 1 and 2 to turn on and off, the forward and reverse rotation of the motor can be realized, and to control the main contacts of the contactors, the coil needs to be controlled. Also, it should be noted that the main contacts of contactors 1 and 2 cannot be closed at the same time, otherwise the power supply will be short-circuited. Control circuit principle: 380V single-phase voltage is converted into 36V safety voltage through a transformer to supply power to the control circuit. The 36V power supply first passed through the thermal relay and the stop switch, then reached the forward button, reverse button, and the normally open KM1 and KM2 respectively. If the forward rotation button SSB1 is pressed, the current will reach the KM1 coil through the normally closed SSB1 and KM2. At this time, the KM1 coil will be energized, and the KM1 main contact will be connected to the motor for forward rotation. At the same time, the KM1 is normally open to connect both ends of SSB1 to realize self-locking, and the KM1 is normally closed to prevent the reverse button SSB2 from being short-circuited by mistakenly pressing it. When the stop button SSB3 is pressed, the KM1 coil is cut off, the KM1 main contact is disconnected, and the motor stops running. The KM1 is normally open and loses its self-locking. If the reverse rotation button SSB2 is pressed, the current will reach the KM2 coil through the SSB2 and the KM1 normally closed. At this time, the KM2 coil will be energized, and the KM2 main contact will be connected to the motor to rotate in reverse. At the same time, the KM2 will be normally open to connect both ends of SSB2 to realize self-locking, and the KM2 normally closed and disconnected will prevent the forward rotation button SSB1 from being pressed by mistake to short circuit. When the stop button SSB3 is pressed, the KM2 coil is cut off, the KM2 main contact is disconnected, and the motor stops running. The KM2 is normally open and loses its self-locking. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Countdown program circuit diagram
We can find some information about the circuit diagram of the countdown program. For example, document [2] mentioned the use of Logisim software to design the circuit schematics of the countdown circuit. The 30-second countdown design based on the 74LS192 was mentioned in document [3], which included the circuit diagram of the countdown timer. The countdown circuit diagram was also mentioned in document [4]. However, there was no specific circuit diagram for the countdown program. Therefore, we can't answer the question of the countdown program's circuit diagram accurately.
Live camera circuit diagram
You only mentioned the " live camera route map ". If there's no more content, I can't integrate and polish the recommendations according to the requirements. You can tell me more about this route map, such as the special design of the route map, the route map for a specific live camera, and so on. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Mono bass circuit diagram
The following are the component parameters of a monophonic power amplifier circuit diagram made with the LM1875T: Resistance: 1M, 22K, 1K, 20K, 1R; Condenser: 2.2UA (best to use an infinite audio), 0.1UA, 100UA, 22UA, 0.22UA. The LM1875 chip's pin function was in the shape of five pins, of which pin 1 was the in-phase signal input, pin 2 was the in-phase signal input, pin 3 was the negative power supply-Vee(single power supply ground), pin 4 was the signal output, and pin 5 was the vcc-input. The standard circuit could be assembled according to the components in the circuit, and there was no need to adjust it. However, this was only a basic example of the power amplifier circuit. For the bass effect, the component parameters in the circuit may need to be further optimized or the circuit may be improved according to specific needs. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to draw the forward and reverse ladder diagram and circuit diagram
The following is a basic method to draw a positive and negative ladder diagram and circuit diagram: ** 1. Confirm control requirements and I/O allocation ** 1. ** Clear control requirements ** - Usually, the forward and reverse control required the motor to rotate forward, reverse, and stop through buttons, and it had to be interlocked with forward and reverse (to prevent short circuits caused by forward and reverse rotation at the same time). It might also require thermal relay for overload protection and other functions. 2. **I/O allocation confirmed ** - ** Inputs **: For example, the start button for forward rotation, the start button for reverse rotation, the stop button, and the overload protection signal of the thermal relay are all used as input signals. These input signals should be distributed to the corresponding input terminal of the PC. For example, in the case of the Mitsui PC, it may be X000, X001, etc., and in the case of the siemen PC, it may be I0.0, I0.1, etc. - ** Outputs **: Forward Contactor Coils and Reverse Contactor Coils are used as the output devices. They should be connected to the corresponding output terminal of the PC, such as Y000 and Y001 of the Mitsubishi-based PC, Q0.0 and Q0.1 of the SIEMEN-based PC, etc. ** 2. Draw the circuit diagram (Take the three-phase induction motor as an example)** 1. ** Main circuit part ** - The three-phase power supply was connected to the fuse (for short-circuit protection) and then connected to the main contact of the contactors. For forward rotation, when the main contact of the forward rotation contactors (KM1) is closed, the three-phase power supply is connected to the motor according to the normal phase sequence, and the motor is rotated forward. For reversal, when the main contact of the reversal contactors (KM2) is closed, the phase sequence of two phases of the three-phase power supply is reversed and then connected to the motor, and the motor is reversed. At the same time, the thermal relay (FT) should be connected to the circuit to detect the current of the motor and automatically cut off the circuit when overloaded. 2. ** Control Circuit ** - ** Forward control circuit **: Lead out from one end of the power supply, first connect the stop button (normally closed), then connect the forward start button (normally open) and the auxiliary normally open contact (for self-locking) of the forward rotating contactors (KM1) in series, then connect the auxiliary normally closed contact (for interlocked) of the reversing contactors (KM2) in series, and finally connect to the coil of the forward rotating contactors (KM1). The other end of the coil returns to the other end of the power supply. - ** Reverse control circuit **: It is also led out from one end of the power supply. First, connect the stop button (normally closed), then connect the reverse start button (normally open) and the auxiliary normally open contact of the reversing contactors (KM2) in series (for self-locking), then connect the auxiliary normally closed contact of the forward rotating contactors (KM1) in series (for interlocked), and finally connect to the coil of the reversing contactors (KM2). The other end of the coil returns to the other end of the power supply. - ** Overload protection part **: The normally closed contact of the thermal relay (FT) is connected in series to the common part of the control circuit (i.e. behind the stop button). When the motor is overloaded, the thermal relay will act, and the normally closed contact will be disconnected, cutting off the entire control circuit. ** 3. Draw the ladder diagram (Take the SIEMens's PL as an example)** 1. ** Forward Rotation Control Logics ** - I0.0 is used as the input signal of the forward start button, I0.1 is used as the input signal of the stop button, I0.2 is used as the input signal of the reverse start button (all are normally open contact input), Q0.0 is used as the output signal of the forward contact coil, and Q0.1 is used as the output signal of the reverse contact coil. - When I0.0 is pressed (the normally open contact is closed) and I0.1 is not pressed (the normally closed contact is closed) and Q0.1 is not energized (the normally closed contact is closed), Q0.0 is energized and self-locked (the normally open contact of Q0.0 is closed to maintain its energized state). - In the ladder diagram, it is represented as: the normally closed contacts of I0.0 and I0.1, the normally closed contact of Q0.1 are connected in series to the coil of Q0.0, and the normally open contact of Q0.0 is connected in parallel with I0.0 to achieve self-locking. 2. ** Reverse control logic ** - When I0.2 is pressed (the normally open contact is closed) and I0.1 is not pressed (the normally closed contact is closed) and Q0.0 is not energized (the normally closed contact is closed), Q0.1 is energized and self-locking. - In the ladder diagram, it is represented as: the normally closed contacts of I0.2 and I0.1, the normally closed contact of Q0.0 are connected in series to the coil of Q0.1, and the normally open contact of Q0.1 is connected in parallel with I0.2 to achieve self-locking. The specific instructions, component representation, and programming rules of different brands of PDLCs (e.g., Samsung, SIEMENS, etc.) may differ, but the basic control logic and design ideas are similar. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Diode Reverse Circuit Diagram Test
Single-Chip Coupled Circuit Diagram
As for the single-chip coupled circuit, in some electrical control products, the input circuit part involved coupling-related content. For example, when the various control signals of traditional electrical equipment are converted into digital signals that match the input/output port of the single-chip computer, the control signals input by the user equipment to the single-chip computer (such as the switch output of the limit switch, the operation button, etc.) are converted through the input circuit, where the input circuit has a coupling-related function. There was also the circuit diagram of the optical coupler-driven relay in the circuit of the single-chip drive relay. The optical coupler-driven relay played a role in the circuit, but the specific circuit diagram needed to be consulted in special documents, such as the circuit diagram of the optical coupler-driven relay (optical coupler/UL2803/switch circuit) and other related information. In addition, the document on the design method of the commonly used drive and coupled circuit of the single-chip I/O for the characteristics of electrical control products may have more detailed design content about the single-chip coupled circuit, but it did not directly give a detailed circuit diagram. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Simulation circuit diagram of the single-chip computer
The following are several examples of simulation circuits related to single-chip processors: - In the ESP32 and Arduino single-chip simulation (such as the website of the website, the simulation circuit that lights up the LED light needs to add an LED light and a current limiting resistance. The negative pole of the LED lamp was connected to the GND pin of the single-chip development board, the positive pole was connected in series with the current limiting resistance, and the other end of the current limiting resistance was connected to the No. 2 pin of the development board. - For the simulation circuit of the steering gear control, add the steering gear in the hardware circuit (the steering gear has three pins, namely, the voltage regulator, the voltage regulator, and the voltage regulator. The voltage regulator is connected to the negative pole of the power supply, and the voltage regulator is connected to the positive pole of the power supply). Then, connect the steering gear to the single-chip computer (if you use the Arduino single-chip computer, you can choose a pin with a "~" to output the voltage regulator signal. In this project, pin 3 is selected as the voltage regulator output pin). - If the simulation uses L298 to drive the direct current motor, the circuit includes the L298N chip (this is a dedicated driver integrated circuit, belonging to the H bridge integrated circuit), the display part uses the PG 160128A (the liquid crystal display dot matrix is 160X128), the input device is a 4X4 matrix keyboard, and it may also include measurement tools such as a virtual scope. The positive and negative rotation of the motor can be controlled by the P1.0 pin of the single-chip computer. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The reason analysis diagram of the alternating positive and negative rotation of the motor
The following is an explanation of the principle of alternating forward and backward rotation of the motor: ##I. Explanation of the principle analysis diagram based on the relay control circuit 1. * * Main circuit part ** - Main switch QF: It is the main switch of the main circuit and the control circuit, mainly used to isolate the power supply and short-circuit protection. - AC contactors KM1 and KM2 main contacts: connected in series in the main circuit, switched on and off to control the positive and negative rotation cycle of the motor. For example, when the KM1 main contact is closed, the motor receives a power input of a phase sequence and turns forward; when the KM2 main contact is closed, the motor receives a power input of a changed phase sequence and turns backward. 2. * * Control circuit part ** - "Relay KC: After pressing the start button, the KC coil is energized, and its normally open contact is closed and locked in the closed position. This is the start of the entire control circuit. - Time Relays KT1 and KT2: - When the KC normally open contact is closed, the KT1 and KM1 coil circuits are connected. The main contact of KM1 is closed to make the motor rotate forward, and the normally closed contact of KM1 is opened (in the coil circuit of KM2) to prevent the reversing contactors from getting electricity when the motor is rotating forward. KT1 was connected in series to the delay contacts of the KM1 and KM2 coil circuits, and the timer started. - When the KT1 delay contact reaches the set time, the delay break contact is opened to cause the KM1 coil to lose power (the main contact of the forward rotating contactors is opened), and the delay close contact is closed. At this time, the KM2 coil and the time relay KT2 coil are energized, the KM2 main contact is closed, and the motor is reversed. The KM2 normally closed contact is opened (in the KM1 coil circuit) to prevent short circuit. - Then, KT2 was connected in series with the time relay delay break contact of the KT1 coil circuit to start timing. When the KT2 delay break contact reached the set time, the KT1 coil lost power, and the two delay contacts of KT1 were reset. Then, the KM2 and KT1 coil lost power, and the KM2 main contact was disconnected. After the relevant contacts were reset, the AC contractor coil KM1 and the time relay KT1 coil were energized again, and so on. ##II. Explanation of the principle analysis diagram of the control system (ladder diagram) 1. * * Forward Rotation Control ** - Press the forward start button, SSB2 (in the ladder diagram, the corresponding X0 turns on), and its normally open contact is connected. The coil of Y0 is "energized" and self-protected, which makes the coil of KM1 energized and the motor starts to rotate forward. Here, the normally closed electric shocks of Y0 and Y1 were connected in series with each other's coil to form an interlocked loop, ensuring that the coil of KM1 and KM2 would not be energized at the same time. 2. * * Reverse Control ** - When the motor is rotating forward (Y0 is on), if you directly press the reverse start button SSB3 (X1 becomes on), the normally closed contact of X1 will be disconnected, causing the Y0 coil to "lose power". At the same time, the normally open contact of X1 will be connected, causing the Y1 coil to "gain power", and the motor will turn from forward to reverse. 3. * * Interlocking mechanism ** - In the ladder diagram, in addition to connecting the normally closed contact of Y0 and Y1 to the coil of the other party in series (called "electrical interlocked "), there was also a" button interlocked ". The normally closed contact of the reverse start button X1 was connected in series with the coil of Y0 that controlled the forward rotation, and the normally closed contact of the forward start button X0 was connected in series with the coil of Y1 that controlled the reverse rotation. This double interlocked ensured the safety and reliability of the forward and reverse rotation control. ##III. Explanation of the principle analysis diagram based on the double interlocked positive and negative rotation control circuit (double interlocked contactors and buttons) 1. * * Forward Rotation Start ** - Press the start button of the SSB1 forward rotation, and its break contact will first break the reverse circuit to realize the button interlocked, and then its contact will close, and the KM1 coil will be energized. The KM1 break-off auxiliary contact first breaks the reverse circuit to realize the mutual locking of the contactors, then the KM1 break-on auxiliary contact and the KM1 main contact are closed at the same time to realize the self-locking, and the motor is energized to rotate forward. 2. * * Reversal activated ** - Directly press the reverse start button of the SK2, and the break contact will first break the forward circuit to realize the button interlocked, and then the contact will be closed, and the KM2 coil will be energized. The KM2 movable break auxiliary contact first breaks the forward rotation circuit to realize the mutual locking of the contactors, then the KM2 movable close auxiliary contact and the KM2 main contact are closed at the same time to realize the self-locking, and the motor is energized to reverse. 3. * * Stop Operation ** - Press the stop button of the SSB3, and the motor will stop running. The double-interlocked circuit overcame the shortcoming that the stop button needed to be pressed when the positive and negative reversing control circuit of the interlocked contactors switched over. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Analysis of the Circuit Diagram for Measuring the Reverse Characteristic of Diode
In the circuit diagram for measuring the reverse characteristics of the circuit, the circuit was connected in the reverse direction, that is, the positive pole of the power supply was connected to N, and the negative pole was connected to P. In this connection method, the direction of the external electric field was the same as the direction of the internal electric field of the junction, which would strengthen the internal electric field, making the thickness of the depletion layer wider and the space charge larger. This made it more difficult for the holes in the P region and the free electrons in the N region to pass through the junction, and the current was greatly reduced. At this time, the current through the junction was mainly drift current. Since the concentration of minority carriers does not change when the temperature is constant, the reverse current does not change with the applied voltage within a certain range. This current is called the reverse saturation current. In the measuring circuit, by changing the size of the variable resistance, the reverse current flowing through the LED under different values of terminal voltage could be measured, thereby depicting the reverse characteristic curve of the LED. From the perspective of the V-A characteristic curve of the LED, the bottom left part is the reverse characteristic part, which can be used to analyze the relevant data and phenomena in the reverse characteristic measurement circuit of the LED, such as the reverse breakdown voltage and other parameters. When the reverse voltage exceeds a certain value, the reverse current will suddenly increase, and this voltage value is the reverse breakdown voltage. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>