Conductor (power cord) for household use generally are copper or aluminum core, the appearance of the foreskin wrapped in a layer or layers of insulation, known as the insulated conductor. With this layer of the coat, even if the lamp lit, hand to touch the wire, not shock. According to the conductor (power line) hard and soft cores, the wire was divided into two kinds of hard lines and soft lines. The cord is made of fine copper wire plastic foreskin lines, often moving electrical equipment, such as hanging lamps lamp line for iron, electric rice cookers and power cord. However, in humid places, such as walls, ceilings, use the protection of insulated wires, ordinary insulated wire, sets of steel or plastic casing to avoid decay leakage.
Wire laying method and location, choice of conductor thickness are not the same. Coarse wire used in the stove room and ambient temperature corresponding to those installed in the pipe protection. Buy a new electrical appliances such as lamps, microwave ovens, all with their own power cord and plug may use to pull a wire, in a convenient place to install a wiring board, and still use the thin wire is not used by the ordinary electric light safe. If the microwave power of 1000 watts, 500 watts, washing machine, iron 300 watts with the use of these appliances, the current increased by several times, the use of time and a long, thin wire and a large resistor, the current circulation, can cause fever and burn the wire plastic coat. ?Usually see some wires of the plastic skin is charred black, is the current is too large sake.
Therefore, the home and add appliances, should check the thickness of the original wiring board wire and into the house power cord. Wire is used to protect the wire, to prevent leakage with, do not use wire, wire hanging wires, lights, or wire wrapped around the handles in the wire.
Thursday, April 12, 2012
An efficient timer management module design
The timer is one of the basic elements of the normal operation of the communication protocol is mainly used for a variety of digital timer
and frame retransmission task. The communication protocol used in the SCM system timer, timing accuracy is not required, but the number of requirements. Hardware resources are limited, it is impossible for every single task is assigned a hardware timer, only through a single hardware timer simulate a number of software timers to meet the timing needs agreement.
These software timer data structure to organize themselves, and provides a uniform interface, called "Timer". Timer management are mainly two kinds of method:
(1) static array method. Timer node is stored in the array. The advantage is simple logic, occupy less ROM. However, this program has significant disadvantages: when the hardware timer interrupt occurs, the subtraction operation of all timer node, the time overhead and delay uncertainty (related to the timer number).
(2)delta linked list method. Ascending order to form a linked list in accordance with the timing value of the timer. A timer value of timer in front of all the timer value plus the value of the node. Thus, in each clock interrupt handler, only the subtraction operation on a timer node, greatly reducing the time overhead. However, the complex program logic, ROM, dosage, require frequent allocation of recovery of memory, easy to form the memory fragmentation.
The timer management module design is based on a static array method. Use a timer node array to hold all of the timing of the request, a representative of an available timer node of the array. Each timer node has a status indicates that the timer is in idle, or overflow state. Timing value of the timer and the timer expires, the message to be sent is also stored in the timer node, in order to achieve a hardware timer to provide users with a number of software timers.
In order to solve the problem of interrupt processing time overhead, the introduction of an auxiliary timer module, auxiliary timer value is always equal to the minimum timing value of all the timer node. In the hardware timer interrupt processing, only the auxiliary timer subtraction operation, which will greatly reduce interrupt processing time.
Start a timer, the main node to node array in an idle state is set to use. If the new timer is enabled, all timers from time to time to the minimum value, but also to update the auxiliary timer. Function pointer to point to the timer message and time value parameters, start the timer process shown in Figure 2. Successful start-up timer, return the node ID number of the timer.
Software timer is driven by the hardware digital timer. In the hardware timer interrupt, the first auxiliary timer value minus 1. If the auxiliary timer value is 0, then the timer value minimum timer has timed out, the corresponding message should be sent to the user task, the node set to the idle state, and re-calculate the timing values ??of the other nodes, and find the timing value the smallest node, update the auxiliary timer.
and frame retransmission task. The communication protocol used in the SCM system timer, timing accuracy is not required, but the number of requirements. Hardware resources are limited, it is impossible for every single task is assigned a hardware timer, only through a single hardware timer simulate a number of software timers to meet the timing needs agreement.
These software timer data structure to organize themselves, and provides a uniform interface, called "Timer". Timer management are mainly two kinds of method:
(1) static array method. Timer node is stored in the array. The advantage is simple logic, occupy less ROM. However, this program has significant disadvantages: when the hardware timer interrupt occurs, the subtraction operation of all timer node, the time overhead and delay uncertainty (related to the timer number).
(2)delta linked list method. Ascending order to form a linked list in accordance with the timing value of the timer. A timer value of timer in front of all the timer value plus the value of the node. Thus, in each clock interrupt handler, only the subtraction operation on a timer node, greatly reducing the time overhead. However, the complex program logic, ROM, dosage, require frequent allocation of recovery of memory, easy to form the memory fragmentation.
The timer management module design is based on a static array method. Use a timer node array to hold all of the timing of the request, a representative of an available timer node of the array. Each timer node has a status indicates that the timer is in idle, or overflow state. Timing value of the timer and the timer expires, the message to be sent is also stored in the timer node, in order to achieve a hardware timer to provide users with a number of software timers.
In order to solve the problem of interrupt processing time overhead, the introduction of an auxiliary timer module, auxiliary timer value is always equal to the minimum timing value of all the timer node. In the hardware timer interrupt processing, only the auxiliary timer subtraction operation, which will greatly reduce interrupt processing time.
Start a timer, the main node to node array in an idle state is set to use. If the new timer is enabled, all timers from time to time to the minimum value, but also to update the auxiliary timer. Function pointer to point to the timer message and time value parameters, start the timer process shown in Figure 2. Successful start-up timer, return the node ID number of the timer.
Software timer is driven by the hardware digital timer. In the hardware timer interrupt, the first auxiliary timer value minus 1. If the auxiliary timer value is 0, then the timer value minimum timer has timed out, the corresponding message should be sent to the user task, the node set to the idle state, and re-calculate the timing values ??of the other nodes, and find the timing value the smallest node, update the auxiliary timer.
Pulsed solenoid valve also called diaphragm valve
Pulsed solenoid valve, also known as diaphragm valves, pulse bag dust clean blowing system of compressed air "switch" control of the output signal pulse jet control device, bag-by-row (room) injection cleaning the resistance of the dust collector to keep within the set range to ensure that the processing power and collection efficiency of the precipitator.
The body coil of the solenoid valve through the wires enter the positive pulse signal generated by the coil flux, so that the moving core pull. When the positive pulse signal input is stopped, dynamic core release, move the core under the action of spring force to return to the initial state to close the valve and another to maintain, and stop the importation of a positive pulse or power can be maintained, need to enter a negative pulse signal can be reset; pulsed solenoid valve working principle is the use of electrical pulses into mechanical pulse of the powerful energy of the pulsating gas into the momentum in a short period of time to release a huge momentum plc control pulse interval should to determine the rated gas pressure recovery time.
Generally installed in the main oil line or shock absorber back-pressure oil, the transmission automatically upshifts and downshift instantaneous pressure drop in the beginning of the locking clutch lock and lift the locking action, in order to reduce the shift and lock to unlock the shock, to make vehicles run more balanced.
Electromagnetic pulse valve when in use, before the environmental conditions is very important, which relates to the electromagnetic pulse valve can not be normal and stable operation down. Electromagnetic pulse valve environmental conditions:
1, according to the power supply types, were selected to the AC and DC solenoid valve. Generally speaking, access to convenient AC power.
2, the use of a corrosive or explosive environments should be given priority according to the security requirements selection of resistance to hair loss.
3, the environmental space restricted, please use the multi-function solenoid valve, because it eliminates the need for bypass and three manual valves and easy online service.
4, the power supply voltage fluctuations are usually exchange selection % -15%, DC to allow ± So, should the ultra poor, to be taken by the regulator measures or make a special order requests.
The maximum and minimum temperatures of 5, the environment should be selected within the allowable range, if the tolerance required for special orders.
6, the conditions of the power of the electromagnetic pulse valve
7, the environment, often the occasion of vibration, bumps and shocks, such as special varieties should be selected, such as marine solenoid valve.
8, the voltage specifications used as preferred AC220V.DC24V.
9, the relative humidity of the environment and water droplets and rain and so on, should be selected the water solenoid valve.
10, select the rated current and power consumption should be based on the power supply capacity should be noted that the VA value of the start of the exchange the higher indirect electromagnetic valve, lack of capacity should be preferred.
The body coil of the solenoid valve through the wires enter the positive pulse signal generated by the coil flux, so that the moving core pull. When the positive pulse signal input is stopped, dynamic core release, move the core under the action of spring force to return to the initial state to close the valve and another to maintain, and stop the importation of a positive pulse or power can be maintained, need to enter a negative pulse signal can be reset; pulsed solenoid valve working principle is the use of electrical pulses into mechanical pulse of the powerful energy of the pulsating gas into the momentum in a short period of time to release a huge momentum plc control pulse interval should to determine the rated gas pressure recovery time.
Generally installed in the main oil line or shock absorber back-pressure oil, the transmission automatically upshifts and downshift instantaneous pressure drop in the beginning of the locking clutch lock and lift the locking action, in order to reduce the shift and lock to unlock the shock, to make vehicles run more balanced.
Electromagnetic pulse valve when in use, before the environmental conditions is very important, which relates to the electromagnetic pulse valve can not be normal and stable operation down. Electromagnetic pulse valve environmental conditions:
1, according to the power supply types, were selected to the AC and DC solenoid valve. Generally speaking, access to convenient AC power.
2, the use of a corrosive or explosive environments should be given priority according to the security requirements selection of resistance to hair loss.
3, the environmental space restricted, please use the multi-function solenoid valve, because it eliminates the need for bypass and three manual valves and easy online service.
4, the power supply voltage fluctuations are usually exchange selection % -15%, DC to allow ± So, should the ultra poor, to be taken by the regulator measures or make a special order requests.
The maximum and minimum temperatures of 5, the environment should be selected within the allowable range, if the tolerance required for special orders.
6, the conditions of the power of the electromagnetic pulse valve
7, the environment, often the occasion of vibration, bumps and shocks, such as special varieties should be selected, such as marine solenoid valve.
8, the voltage specifications used as preferred AC220V.DC24V.
9, the relative humidity of the environment and water droplets and rain and so on, should be selected the water solenoid valve.
10, select the rated current and power consumption should be based on the power supply capacity should be noted that the VA value of the start of the exchange the higher indirect electromagnetic valve, lack of capacity should be preferred.
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