Diagram of the motor control unit icons and symbols

The following is a circuit diagram of a motor reverse rotation time control: As for the physical connection diagram, there was a problem with the control of the two AC contactors. The control requirement was to press the self-locking button SSS, and the motor would run clockwise (forward) for 35 seconds, counterclockwise (reverse) for 30 seconds, and then the motor would run forward for 35 seconds, and so on. Press the button SSS again, and the motor would stop running. A simple loop control circuit could be controlled by a relay. In the teaching materials, the symbol of an energized delay relay could be used to replace the double delay time relay, and a pulse counter (its function was the same as the double delay time relay) could also be used to replace the simulation. The double delay loop interlocked time relay used two independent time relay T1 and T2 to be interlocked to form a loop closing and opening working mode. The delay time of T1 and T2 was set independently. With the choice of time base, it could be set freely within a certain range. In a three-phase induction motor control system, KM1 and KM2 were AC contactors that controlled forward and reverse operation respectively. In the ladder diagram, two start-stop circuits were used to control the forward and reverse rotation of the motor. Pressing the start button for forward rotation, the corresponding input point X0 turned ON, and its normally open contact was connected. The coil of Y0 was "energized" and self-protected, so that the coil of KM1 was energized, and the motor began to rotate forward. Press the stop button, and X2 will turn ON, and its normally closed contact will be disconnected, causing the Y0 coil to "lose power" and the motor to stop running. In the ladder diagram, the normally closed contacts of Y0 and Y1 were connected in series with each other's coil (this was called "interlocked" in the relay circuit). At the same time, a "button interlocked" was also set, which was to connect the normally closed contact of the reverse start button X1 in series with the coil of Y0 that controlled the forward rotation, and connect the normally closed contact of the forward start button X0 in series with the coil of Y1 that controlled the reverse rotation. This setting can achieve positive and negative rotation control and ensure that the coil of KM1 and KM2 will not be energized at the same time. For the positive and negative transfer wires of the three-phase motor, press the forward rotation button circuit control button SP2, the KM1 coil, and the KM2 normally closed contact. The power is connected, and the forward rotation coil is energized to start the motor. At the same time, the normally closed contact of the KM1 is disconnected, and the KM2 coil connected in series cannot be connected. Press the reverse rotation button circuit control button SSB3, the KM2 coil, and the KM1 normally closed contact. The power is connected, and the reverse coil is energized to start the motor. At the same time, the normally open contact of the KM2 is disconnected, and the KM1 coil connected in series cannot be connected. These were part of the circuit diagram principles involved in the motor's forward and reverse rotation time control circuit. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The symbol of the transformer is C. In the international system of units, the unit of capacity was farad, or French for short, and the symbol was F. Because the unit Farad was too large, the commonly used units of capacity were millifarad (mF), microfarad (pF), nanofarad (nF), and picofarad (pF). The conversion relationship was: 1 Farad (F)= 1000 milliFarad (mF)=1000000 microFarad (uF);1 microFarad (uF)= 1000 nanofarad (nF)= 1000000 picofarad (pF). An example of how to read a voltage is as follows: 105 = 1000000pF = 1000nF = 1 pF;104 = 100000pF = 100nF = 0.1 pF;103 = 10000pF = 10nF = 0.01 pF;102 = 1000pF = 1nF = 0.001 pF;224 = 22×10 pF = 220000pF = 220nF = 0.22uF. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

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>

The electronic fuel injection system used the electronic control unit as the control center. It used various sensors installed on the engine to measure the operating parameters of the engine, and then accurately controlled the fuel injection amount of the fuel injection according to the pre-stored control program in the computer, so that the engine could obtain the best air-fuel ratio of the flammable mixture under various working conditions. In the entire system, the Electronic Control Unit (CPU) played a key role. For the control of the fuel injection amount, the CPU will collect the engine speed signal and load signal for analysis to determine the basic fuel injection amount (fuel injection pulse width), and correct it according to the cooling liquid temperature signal and other signals to obtain the total fuel injection amount. In terms of fuel injection timing control, for an engine with multi-point sequence injection, the CPU controls the fuel injection time at the best time according to the ignition sequence of each cylinder of the engine to ensure that the gasoline injected into the cylinder is fully burned. In addition, the CPU also played a role in fuel cut-off control, which included normal deceleration fuel cut-off control (when the vehicle suddenly released the accelerator pedal, the CPU automatically cut off the fuel injection control circuit and stopped the fuel injection. When the engine speed dropped to the critical speed, the fuel supply was resumed) and overrun fuel cut-off control (when the engine reached the critical speed or the set maximum speed, the CPU cut off the control circuit of the electric fuel pump and stopped the fuel injection to prevent the vehicle from speeding). For the fuel pump control, after the ignition switch is turned on, the CPU will make the fuel pump work for 2 - 3 seconds to establish the oil pressure when the engine starts. The fuel pump will maintain normal operation during the engine starting and running process. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The electronic control unit in the electric control system of the new energy vehicle was the core component, which was mainly composed of sensors, control units, and actors. In hybrid vehicles, the electronic control unit needed to go through various complicated adjustments before it could be applied. This process was similar to the adjustment between the engine and the transmission of a fuel car. It required long-term experience to achieve obvious results. Toyota had done in-depth research on the electronic control management system of hybrid vehicles. For example, in the charging and discharge of the battery pack and kinetic energy recovery, Toyota divided the battery structure and controlled the charging capacity in the area that was not easy to age; The battery pack was equipped with a battery temperature control system that inhibited battery aging; The upper limit of the charging range was limited to 90%, so that when the kinetic energy recovery system was used, there was sufficient capacity to collect the kinetic energy brought by the brakes and increase the safety of driving downhill on long slopes. These were the manifestations of the hybrid vehicle's electronic control unit in the research and development results of different car companies. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

For a 24V motor with a high current, it could generally be controlled by a MOS tube or an IGBT. Relatively speaking, an mos was a more economical and practical choice. You can use a single-chip computer to build an H-bridge drive circuit to drive a 24V brush motor. First, draw the H-bridge drive circuit. In the protues, you can use a high-voltage driver chip like the ICR2101 (24V is considered low voltage compared to the voltage it can drive) to build the circuit. At the same time, you need to consider the addition of some other circuit components, such as the addition of a circuit. Because there was an interelectrode capacity (between the G and S poles) inside the MOS tube, the resistance coming out of the G pole and the interelectrode capacity of the GS formed an RC-charge and discharge circuit. By adjusting this resistance, the rise time of the MOS output from the low level to the high level of the dimming pulse could be adjusted. A parallel connection of the G-pole resistance with a second voltage could make the discharge time of the dimming pulse from the high level to the low level faster, thus affecting the fall time. In addition, when it came to the single-chip processor receiving the signal from the 24V passive switch, the 24V high frequency needed to be reduced to the single-chip processor pin frequency. In the motor control, by controlling the operation of turning on and off the MOS tube in the H-bridge circuit, the motor was controlled and started. For example, through the electromagnetic coil of the contactors in the control circuit, the power supply of the main circuit of the motor was switched on and off to start the motor. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The following is an example of how to realize the delay of the positive and negative rotation of the motor: ** 1. Electric Connection ** 1. ** Electric motor control circuit ** - The motor has two control modes, remote control and local control. The switch can be used for conversion. The local control is started by the button beside the machine. Generally, the self-reset button is used. Press the start button and release the stop button. The remote control was controlled by the PC to start and stop the motor. - The output points (such as Q1.0 and Q1.1) of the PC control the intermediate relay coil, which in turn controls the suction of the contactors-K01 and-K02 to control the start and stop of the motor. Here, two self-reset buttons (such as- S11, - S12) are used as the start enable, and- S13 is used as the motor stop signal. The I/O point of the PC and the motor control circuit have corresponding electrical connections. 2. ** Principle ** - Take the forward rotation control as an example. Press the- S11 button, and the I0.2 of the PC will input a pulse signal. After the "PR" trigger (reset priority), the relevant signal will become 1 and start the delay timer (such as T10). After a certain delay time (such as 10 seconds), the forward rotation command will be issued to make Q1.0 become 1, and the motor will run forward. During this process, if the stop button- S13 is pressed, the relevant signals will change and stop the motor operation or the timer. The principle of reverse control was similar. ** 2. Program Control ** 1. ** Signal processing ** - First, scan the input signal status to obtain the status information of the start button, stop button, and so on. 2. ** Forward and Reverse Delay Logics ** - When the start enable signal arrives (such as pressing the forward start button- S11 or reverse start button- S12), start the delay timer first. Before the delay time of the timer is up, the motor will not start. For example, in the forward rotation, after the timer delays for 10 seconds, the relevant operation command signal becomes 1, and when it is 1 at the same time as the forward rotation control signal, after the "and" operation, the output signal of the output point of the Plc (such as Q1.0) makes the motor rotate forward. The same is true for reverse rotation, but the corresponding output point of the Plc (such as Q1.1) controls the reversing contactors. - During the operation of the motor, if the stop button is pressed, it will change the relevant logic signal, causing the motor to stop running, and the timer will stop counting (if it is still in the counting state) until the next time there is a start signal. The same logic could be applied to the mitsui plcs, for example, by setting appropriate instructions and logical judgments to achieve the delay of the motor's positive and negative rotation. At the same time, in practical applications, factors such as the power of the motor, the stability of the control method, and safety needed to be considered. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

If the electronic control unit of the Phaeton brake is incorrectly programmed, the electronic handbrake module needs to be recoded and the basic settings and brake gap adjustment needs to be carried out. If the new control unit was not codified or the code was lost, the code of the original control unit must be read before replacing the control unit. If the code of the original control unit could not be read, the corresponding code must be found with the part number. If the code is entered incorrectly, there will be an unknown fault code. Different part numbers and model year code values are different. After the code is completed, it may be necessary to make basic settings for the fault code (such as 01087) that has not been implemented. The method is to enter Special Function → Choose Electronic Park → and then set the release and recovery function.(e.g. Fault code 01279). After the above fault code processing is completed, the brake control unit-read fault code (e.g. Fault code 01316) will be automatically cleared. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>

The following is the general idea of programming the motor reverse rotation control based on the S (set) and R (reset) commands: ##I. I/O allocation 1. ** Entering Device ** - A stop button (such as I0.0) is required to stop the operation of the motor. - Forward rotation button (for example, I0.1). When this button is pressed, the motor will start in the forward direction. - Reverse button (e.g. I0.2), press this button to start the motor in reverse. 2. ** Outputting Device ** - Forward Contactor (e.g. Q0.1), used to control the opening and closing of the forward circuit of the motor. - Reverse Contactor (such as Q0.2), which controls the connection and interruption of the motor reverse circuit. ##2. Program logic 1. ** Forward Rotation Control Logics ** - When the Forward Rotation button (I0.1) is pressed, use the S command to set the Forward Rotation Contactor (Q0.1), and the motor starts to rotate forward. At the same time, in order to prevent the forward and reverse rotation from running at the same time, it was necessary to use interlocked logic. That is, when Q0.1 is set, the logic of the normally closed contact Q0.1 is inverted and then connected in series with the reversal control logic to ensure that the reversal contactors (Q0.2) cannot be energized. - When the stop button (I0.0) is pressed, use the R command to reset the forward rotating contactors (Q0.1), and the motor stops rotating forward. 2. ** Reverse control logic ** - When the reverse button (I0.2) is pressed, use the S command to set the reversing contactors (Q0.2), and the motor will reverse. Similarly, when Q0.2 is set, the logic of the normally closed contact Q0.2 is inverted and connected in series with the forward rotation control logic to prevent the forward rotation contactors (Q0.1) from being energized. - When the stop button (I0.0) is pressed, the reversing contactors (Q0.2) are reset through the R command, and the motor stops reversing. The following is a simple ladder diagram example (described in a programming style similar to the ladder diagram of a PC): ###(I) Forward Rotation |--I0.1 (Forward Turn button)--|S|--Q0.1 (Forward Contactor)--| |--Q0.1 (normally closed)--||--I0.2 (Reverse button)--|(Interlocking logic) |--I0.0 (stop button)--|R|--Q0.1 (Forward Contactor)--| ###(2) Reverse Part |--I0.2 (Reverse button)--|S|--Q0.2 (Reverse Contactor)--| |--Q0.2 (normally closed)--||--I0.1 (Forward Turn button)--|(Interlocking logic) |--I0.0 (stop button)--|R|--Q0.2 (Reverse Contactor)--| In this way, the positive and negative rotation control programming of the motor could be realized through the S and R instructions and the interlocked logic. In actual programming, it was also necessary to consider the protection mechanism of the motor, such as overload protection, and make appropriate adjustments according to the specific model of the PC and the programming environment. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>