Power Quality Optimization with Active Harmonic Filter It is widely believed that active harmonics filters AHF are very costly and, therefore, are the last choice. INTRODUCTION. You are at the best, free online Basic Electronics Course. Just read the brief blocks of text, view the videos, and check out some of the screened. Issuu is a digital publishing platform that makes it simple to publish magazines, catalogs, newspapers, books, and more online. Easily share your publications and get. Introduction Given the wide variety of generators manufactured for different markets, it is important to understand the benefits and drawbacks to each when it comes. Strobe Lights and Design Guidelines, Useful Circuits, and Schematics. Strobe Lights and Design Guidelines, Useful Circuits, and Schematics. Document Version 2. Last Updated 0. 52. Strobe Lights and Design Guidelines, Useful Circuits, and Schematics. Copyright c 1. 99. All Rights Reserved. Reproduction of this document in whole or in part is permitted if both. This notice is included in its entirety at the beginning. There is no charge except to cover the costs of copying. Thanks to Don Klipstein email donmisty. His Web site http www. All modern electronic flash units often called photographic strobes are. All of these use the triggered. The typical electronic flash consists of four parts 1 power supply. An electronic flash works as follows. The energy storage capacitor connected across the flashtube is charged. V typical power supply. This is either a battery or AC adapter. AC line. operated supply using a power transformer or voltage doubler or tripler. These are large electrolytic. Back to Troubleshooting Table of Contents. Tools, Test Equipment, and Other Stuff Hand Tools Invest in good tools. If you are into garage sales, you can often pick up. MMU offers various engineering courses in Biotechnology, Civil Engineering, Electrical Engineering, Computer Science Engineering etc. Apply now for admissions 2. Capacitor discharge tool. A suitable discharge tool for each of these applications can be made as quite easily. The capacitor discharge indicator circuit. The database recognizes 1,746,000 software titles and delivers updates for your software including minor upgrades. F at 3. 00 V designed specifically for the rapid. A ready light indicates when the capacitor is fully charged. Most. monitor the voltage on the energy storage capacitor. However, some. detect that the inverter or power supply load has decreased indicating. Normally, the flashtube remains non conductive even when the capacitor. A separate small capacitor e. F is charged from the same power. Contacts on the cameras shutter close at the instant the shutter is. These cause the charge on the trigger capacitor to be. Excellent It Smps Transformer Calculation Tool' title='Excellent It Smps Transformer Calculation Tool' />The pulse generated by this trigger typically around 4 1. KV depending. on the size of the unit is enough to ionize the xenon gas inside the. Still Electronic Workbench EWB 5. LG TVs horizontal scanning times and TL494 SMPS control of integrated electronic workbenchs simulation. BU403 Charging Lead Acid. Learn how to optimize charging conditions to extend service life. The lead acid battery uses the constant current constant voltage CCCV. The xenon gas suddenly becomes a low resistance and the energy storage. The energy of each flash is roughly equal to 12C2 in watt seconds. W s where V is the value of the energy storage capacitors voltage and. C is its capacitance. Not quite all of the energy in the capacitor is. The energy storage capacitor for pocket cameras. F at 3. 30 V charged to 3. V with a typical flash. W s. For high power strobes, 1. F at higher voltages. W s or more. Another important. For pocket cameras it may be several. For a studio speed. Typical flash duration is much less than a millisecond resulting in crystal. On cheap cameras and probably some expensive ones as well physical contacts. Better designs use an SCR or other electronic switch so that no high. Note that for cameras with focal plane shutters, the maximum shutter speed. X Sync is typically limited to 16. The reason is that for higher shutter speeds, the entire picture. Rather, a slit with a width determined the by the effective. For example, with a. Since. the flash duration is extremely short and much much less than the focal. Excellent It Smps Transformer Calculation Tool' title='Excellent It Smps Transformer Calculation Tool' />For shutter speed settings longer than the travel. See the chapter Complete Strobe Schematics for typical circuit. Red eye reduction provides a means of providing a flash twice in rapid. The idea is that the pupils of the subjects eyes close somewhat. This may be done by using the main flash but many cameras use a small, bright. This approach. works. Using the main flash would require sub second recycle time which is. Vivitar AutoThyristor 2. However, it would add. A separate little bulb is effective and much. Failure of red eye reduction or the automatic exposure control circuits will. However, some of. For red eye in particular, It is also. Remotely triggered fill flashes use a photocell or photodiode to fire. SCR or light activated SCR which emulates the camera shutter switch. There is little to go wrong. Automatic electronic flash units provide an optical feedback mechanism to. The flash is then. This means. that the flash duration will differ depending on exposure typically from. Inexpensive automatic flash units just short across the flashlamp with an. SCR or second internal quench tube an internal small xenon tube that looks. See the. sections starting with Vivitar Auto 2. With. these units, the same amount of energy is used regardless of how much light is. The excess energy is. Note that it is not the distance to the subject that matters but. The travel. time of the light has nothing to do with controlling exposure. More sophisticated units use something like a Gate Turn. Off Thyristor GTO. See the. section Vivitar AutoThyristor 2. These use only as much energy as needed and the batteries last much longer. Furthermore. when using low power flashes, the cycle time is effectively zero since the. Therefore. multiple shots can be taken in rapid succession. Failure of the automatic exposure control circuits will probably require a. However, some of these use fairly. There are two potential hazards in dealing with the innards of electronic. The energy storage capacitor. Even on small pocket camera electronic. F at 3. 30 VDC. This is 5 2. W s which is enough to kill you under the right wrong conditions. Hot shoe or side mounted electronic flash units have energy storage. F or more. High performance studio speed lights may have 1. Xenon strobes for pumping of solid state laser rods and other industrial. KV power supplies with 1. W s energy storage capacitors touch one of these and you will be. High voltage with high energy storage is an instantly deadly combination. Treat all of these capacitors even those in tiny pocket cameras with. Always confirm that they are discharged before even thinking. On larger systems especially, install a shorting. Better to kill the power supply than yourself if you forget to. Line connected no power transformer have all the dangers associated. AC line power in addition to the large power supply and energy. Microsoftoffice Software: Software here. Always use an isolation transformer when probing. However, keep in mind that the power supply. Additional important safety information regarding shock, excessively bright. Reading and following these recommendations and heeding the warnings is. These guidelines are to protect you from potentially deadly electrical shock. Note that the danger to you is not only in your body providing a conducting. Any involuntary muscle contractions. The purpose of this set of guidelines is not to frighten you but rather to. Electronic construction. Just be sure that it is also safeDont work alone in the event of an emergency another persons presence. Always keep one hand in your pocket when anywhere around a powered. Wear rubber bottom shoes or sneakers. Wear eye protection large plastic lensed eyeglasses or safety goggles. Dont wear any jewelry or other articles that could accidentally contact. Set up your work area away from possible grounds that you may accidentally. Know your equipment TVs and monitors may use parts of the metal chassis. AC line. Microwave ovens use the chassis as ground. In addition, do not assume that the chassis. If circuit boards need to be removed from their mountings, put insulating. Hold them in. place with string or electrical tape. Prop them up with insulation sticks. If you need to probe, solder, or otherwise touch circuits with power off. W or greater. resistor of 1. V approximate value e. V capacitor. use a 2. K 1. 0K ohm resistor. Monitor while discharging andor verify that. Connectdisconnect any test leads with the equipment unpowered and. Use clip leads or solder temporary wires to reach cramped. If you must probe live, put electrical tape over all but the last 11. Clip the reference end of the. Perform as many tests as possible with power off and the equipment unplugged. For example, the semiconductors in the power supply section of a TV or. Charging Information For Lead Acid Batteries Battery University. Learn how to optimize charging conditions to extend service life. The lead acid battery uses the constant current constant voltage CCCV charge method. A regulated current raises the terminal voltage until the upper charge voltage limit is reached, at which point the current drops due to saturation. The charge time is 1. With higher charge currents and multi stage charge methods, the charge time can be reduced to 81. Lead acid is sluggish and cannot be charged as quickly as other battery systems. See BU 2. 02 New Lead Acid Systems. Lead acid batteries should be charged in three stages, which are 1 constant current charge, 2 topping charge and 3 float charge. The constant current charge applies the bulk of the charge and takes up roughly half of the required charge time the topping charge continues at a lower charge current and provides saturation, and the float charge compensates for the loss caused by self discharge. During the constant current charge, the battery charges to about 7. The topping charge is essential for the well being of the battery and can be compared to a little rest after a good meal. If continually deprived, the battery will eventually lose the ability to accept a full charge and the performance will decrease due to sulfation. The float charge in the third stage maintains the battery at full charge. Figure 1 illustrates these three stages. The switch from Stage 1 to 2 occurs seamlessly and happens when the battery reaches the set voltage limit. The current begins to drop as the battery starts to saturate full charge is reached when the current decreases to 35 percent of the Ah rating. A battery with high leakage may never attain this low saturation current, and a plateau timer takes over to end the charge. The correct setting of the charge voltage limit is critical and ranges from 2. V to 2. 4. 5V per cell. Setting the voltage threshold is a compromise and battery experts refer to this as dancing on the head of a needle. On one hand, the battery wants to be fully charged to get maximum capacity and avoid sulfation on the negative plate on the other hand, over saturation by not switching to float charge causes grid corrosion on the positive plate. This also leads to gassing and water loss. Temperature changes the voltage and this makes dancing on the head of a needle more difficult. A warmer ambient requires a slightly lower voltage threshold and a colder temperature prefers a higher setting. Chargers exposed to temperature fluctuations include temperature sensors to adjust the charge voltage for optimum charge efficiency. The charge temperature coefficient of a lead acid cell is 3m. VC. Establishing 2. C 7. 7F as the midpoint, the charge voltage should be reduced by 3m. V per cell for every degree above 2. C and increased by 3m. V per cell for every degree below 2. C. If this is not possible, it is better to choose a lower voltage for safety reasons. Table 2 compares the advantages and limitations of various peak voltage settings. V to 2. 3. 5Vcell. V to 2. 4. 5Vcell. Advantages. Maximum service life battery stays cool charge temperature can exceed 3. C 8. 6F. Higher and more consistent capacity readings less sulfation. Limitations. Slow charge time capacity readings may be inconsistent and declining with each cycle. Sulfation may occur without equalizing charge. Subject to corrosion and gassing. Needs water refill. Not suitable for charging at high room temperatures, causing severe overcharge. Table 2 Effects of charge voltage on a small lead acid battery. Cylindrical lead acid cells have higher voltage settings than VRLA and starter batteries. Once fully charged through saturation, the battery should not dwell at the topping voltage for more than 4. This is especially critical for sealed systems because they are less tolerant to overcharge than the flooded type. Charging beyond the specified limits turns redundant energy into heat and the battery begins to gas. The recommended float voltage of most flooded lead acid batteries is 2. V to 2. 2. 7Vcell. Large stationary batteries at 2. C 7. 7F typically float at 2. Vcell. Manufacturers recommend lowering the float charge when the ambient temperature rises above 2. C 8. 5F. Figure 3 illustrate the life of a lead acid battery that is kept at a float voltage of 2. V to 2. 3. 0Vcell and at a temperature of 2. C to 2. 5C 6. 0F to 7. F. After 4 years of operation permanent capacity losses become visible, crossing the 8. This loss is larger if the battery requires periodic deep discharges. Elevated heat also reduces battery life. See also BU 8. 06a How Heat and Loading affect Battery Life. Figure 3 Capacity loss on standby. Permanent capacity loss can be minimized with operating at a moderate room temperature and a float voltage of 2. Vcell. Source Power Sonic. Not all chargers feature float charge and very few road vehicles have this provision. If your charger stays on topping charge and does not drop below 2. Vcell, remove the charge after 4. Recharge every 6 months while in storage AGM every 61. These described voltage settings apply to flooded cells and batteries with a pressure relief valve of about 3. Pa 5psi. Cylindrical sealed lead acid, such as the Hawker Cyclon cell, requires higher voltage settings and the limits should be set to manufacturers specifications. Failing to apply the recommended voltage will cause a gradual decrease in capacity due to sulfation. The Hawker Cyclon cell has a pressure relief setting of 3. Pa 5. 0psi. This allows some recombination of the gases generated during charge. Aging batteries pose a challenge when setting the float charge voltage because each cell has its own unique condition. Connected in a string, all cells receive the same charge current and controlling individual cell voltages as each reaches full capacity is almost impossible. Weak cells may go into overcharge while strong cells remain in a starved state. A float current that is too high for the faded cell might sulfate the strong neighbor due to undercharge. Cell balancing devices are available compensate for the differences in voltages caused by cell imbalance. Ripple voltage also causes a problem with large stationary batteries. A voltage peak constitutes an overcharge, causing hydrogen evolution, while the valley induces a brief discharge that creates a starved state resulting in electrolyte depletion. Manufacturers limit the ripple on the charge voltage to 5 percent. Much has been said about pulse charging of lead acid batteries to reduce sulfation. The results are inconclusive and manufacturers as well as service technicians are divided on the benefit. If sulfation could be measured and the right amount of pulsing applied, then the remedy could be beneficial however giving a cure without knowing the underlying side effects can be harmful to the battery. Most stationary batteries are kept on float charge and this works reasonably well. Another method is the hysteresis charge that disconnects the float current when the battery goes to standby mode. The battery is essentially put in storage and is only borrowed from time to time to apply a topping charge to replenish lost energy due to self discharge, or when a load is applied. This mode works well for installations that do not draw a load when on standby. Lead acid batteries must always be stored in a charged state.