Introduction
Consider the sentence referred to as “Murphy’s Law,” the old adage: “All things that can go wrong will be wrong.”. Over the last 50 years, based on the electronic components of the system was fully developed, was able to provide exceptional high-reliability very advanced monitoring and control. Reliability is generally concerned because people’s lives are potentially dangerous, followed by failure due to damage caused by user satisfaction and the decline of the product. However, things are never perfect, and therefore always need to continually improve the reliability to produce safe, durable electronic systems. Inspiron E1505 battery Latitude 131L battery
When system reliability must be guaranteed and no choice, it is preferable, but also the most expensive is to use fully redundant circuits. Exactly the same circuit at the same time perform the same function, but also the results of the application form to vote, to produce permanent results safest. In many such systems, where fault circuit is detected, then automatically delete the circuit, and use a backup circuit instead of the same. For long-term operating reliability is the ideal topology. On the other hand, the consequences of failure are not always able to prove that a completely redundant because of the high cost is reasonable. These systems use only rely on the inherent reliability of each component. Failure of a single component could seriously damage the system or permanent damage to the precision. The design assumptions of this nature, there are many risks, but can achieve the lowest cost. Vostro 1000 battery Inspiron 510m battery
On systems highly reliable in the middle lane is a lack of supervision, using this method, the circuit monitors a variety of system components, and report any discrepancies. As in the circuit anywhere, at any moment anything can happen, so the best elements to monitor. For the deficiencies found in the answer will be changed from fully closed system (eg on the train often closed switch emergency stop) to a simple alarm service (similar to the dashboard of car “Idiot Light “) and others.
This article describes how, using the LTC6801 failure to monitor IC, raising a high-voltage lithium-ion battery for long-term reliability. In electric car, uninterrupted power supplies, medical equipment and even applications such as power tools, use batteries to power is a current trend of development of these applications, each with varying degrees of confidence of reliability . Inspiron 600m battery Latitude D500 battery
Challenges long battery life
For electric cars and many other types of portable devices, the battery has become one of the major sources of energy. The lithium-ion batteries are very popular because with the same energy density compared with other chemicals to form a lithium-ion battery energy density lithium, ion battery pack to allow smaller, lighter. For high power applications like electric cars require hundreds of batteries stacked to form a high voltage supply, which produces a small current supply, you can use thinner and lighter wire. In such automotive applications, driver safety is number one, followed by a vehicle owner satisfaction. Therefore, to achieve safe and reliable long-term reasons are obvious. To achieve this, the monitoring of each section of the battery must be continuous in order to use the case for many years to maintain optimal levels. Latitude D505 battery Latitude D510 battery
In the simplest case, asked the circuit for measuring battery voltage of each cell. This measure is normally ensured by the implementation of an AD converter AD converter to pass information to a microcontroller. The controller carefully manage the entire battery charge and discharge, so the battery will not work beyond the scope of a strict, but beyond this range in May significantly shorten the life of the battery. The face of a system, there may be hundreds of individual cells, a measurement integrated circuit can save a significant number of components. LTC6802 from Linear Technology is a company offers integrated functional components. With a built-in 12-bit ADC, which can measure and report as many as 12, and two temperature sensors on the battery voltage. Any number of batteries can be stacked with each other, the measure for each group (consisting of 12 cells) standard voltage sent to a host microcontroller. These measuring devices and controllers to form the core management system of the battery. Latitude D520 battery Latitude D600 battery
For the extended life battery available for each section carefully monitor the state of battery charge is extremely important, but perhaps not sufficient for customer satisfaction increasingly high automotive. On the sensitive electronics, car show, a hostile and dangerous operations. For worry-free access to long-term satisfaction with the system of “what if” analysis is necessary. Perhaps some questions to consider are:
If you connect a wire disconnected the battery What happens?
If the offset measurement accuracy of the voltage what will happen?
If the internal register bits to maintain a constant value of always done a good voltage readings of battery, what happens?
If the measurement of IC does not know how the system voltage transient has been seriously damaged, and what happens? Latitude D610 battery PC764
Potential problems deepest May incorrectly identify the controller, a battery or battery in perfect condition, but the truth is that the battery or the battery is not the correct method of measurement. Later, these batteries are fully discharged in May or electricity dangerous overtaking, while the system had no conscience a little. Need something to “control the controllers, to achieve a higher level of reliable operation.
Completed the system LTC6801 Battery Management (BMS), a lack of supervision
On an entirely redundant measurement may replace the program is the fault monitoring circuit and the measuring device in parallel to act as examining the basic functions of the system. Figure 1 shows a circuit of 12 lithium-ion batteries including the implementation of such programs, the program uses a measuring device LTC6802 and LTC6801 fault that parts of the monitor. Latitude D620 battery Latitude D820 battery
Through the measurement and reporting in accordance with instructions for each section of the battery voltage, and will be added to the battery discharge current breakdown of each section on drums, LTC6802-1 to become the main system components electronic. Data through the SPI serial data link to send to the controller. At the same time, the LTC6801 also monitors the battery cells in each section. Without the intervention of the system controller, LTC6801 can be periodically voltage of each cell sample, and perform a simple comparison of the undervoltage and overvoltage. If all conditions are normal, then the LTC6801 output in the state (status output) line to provide a differential clock signal. If there is something wrong, then the clock stopped. As for the problem, LTC6801 provides no information because it is indicative not only something right. Once the clock stops, then the controller can perform diagnostic procedures to determine what problems occurred?
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LTC6801 design a lot of careful consideration of possible system failures, and also the ease of use. An important design requirement was to enable the device to operate automatically, without any software. External demand is the only power supply (battery pack itself), and activation / deactivation of the clock signal. Did not allow the clock input, LTC6801 will remain static in a state of low power, usable only by the battery a little current AU. The clock can be activated by the system controller or any other source of the oscillator (such as silicon oscillator LTC6906) to provide. One received a clock signal, the unit will automatically wake up and begin monitoring all batteries.
Select overvoltage (OV) is the threshold in order to use with a 3.3V and 4.2V nominal voltage level alarm lithium-ion, while the under voltage (UV) threshold for the battery runs provide a reasonable instruction. OV and UV thresholds by a different pin configuration, so all combinations are possible. OV and UV levels should be defined so as not too close to the battery voltage normal, you can directly something may be wrong, or likely to cause nuisance transition detection circuit faults occur. Inspiron 640m battery Inspiron E1405 battery
There may be threshold settings for this fixed delay of up to 500 mV. When the detected fault triggered actions that cause changes in battery voltage, such as immediately disconnect the load with the battery connection, a fixed hysteresis useful. Hysteresis can jump in and out of trouble to prevent the state.