By admin
http://www.cwhdallas.com/nos-capacitors/
Nos Capacitors
 |
Cadence Acoustics NOS1.5 1.5 Farad Extreme Power Stiffening Capacitor
List Price: $199.00
Sale Price: $199.00
|
|
|
Today's car audio amplifiers need huge amounts of current. Often a vehicle's electrical system is unable to provide it. With your car's air conditioning running, the factory electrical charging system may already be operating at only 70% of full capacity. When a bass note hits or when playing your system very loudly, there may not be enough electrical energy to power your amplification system properly causing your music to sound strained and distorted. Cadence capacitors are designed to store enough electrical current and to release this energy extremely fast due to their superior design and low internal resistance. In addition, as quick as your amplifier needs a new current surge, your Cadence capacitor will provide it. This continuous cycle of power discharge and recharge guarantees flawless bass playback.
|
Last month, I had received approximate 2~5 nos of faulty lcd monitors everyday from customers lived in a residential area occupied by 20000 people. I have never got such a good harvest indeed. How much wages do I get from the repair only? Unbelievable! It is $6400 roughly which calculates from average $80 x 80 nos lcd monitor.
I can tell you that approximately 40 percent of total faulty monitors are easy to be repaired normally and the rest is a bit time consuming but it is worth to perform electronic component analyzing, testing and replacement. Once you got the culprit, you solder it out and replace the new part and solder it back on the circuit board.
One of the most important and essential techniques in servicing lcd monitor is the SOLDERING technique which will bring you fast dollars easily and quickly. I believe most repairers will agree with me.
Let take few real soldering examples as follows:
Case 1: Compaq FP731 shutdown from few seconds to few minutes
Solution 1: Re-solder the feedback circuit of the ccfl inverter section C215, C216, D201, D204, R215, R246, R218, D206, C242, D210, R234, R243
Case 2: BenQ T705 got display shutdown after power on for few second
Solution 2: Solder out 4 nos. shorted C5707 transistors and solder new transistors back.
Case 3: Dell e151fp ( equivalent to Acer FP553 Chassis ) No power or power on then shutdown shortly
Solution 3: Solder out the faulty C605, C707, C703 capacitor, the faulty power ic UC3842B, faulty resistors R613, R623, R615, faulty transistor Q601, faulty diode D604= 1N4148 and fuse F601. Solder the new parts back into the circuit.
From above examples, no matter how severe fault level of lcd monitor, the soldering work is always involved in repairing lcd monitor. You can find the following articles explain the basic soldering to advance soldering technique of the surface mounted devices (SMD) on our website.
1) Tools for soldering
2) Soldering safety and health
3) Photos for soldering dry joints on circuit boards
4) Basic soldering technique
5) Advanced Smd soldering technique
6) Quick and inexpensive soldering station
Once you master the soldering skill, you can apply this useful skill to fix the fault electronic component on any circuit boards. Start practice and practice make perfect.
Ck is the writer of http://www.LcdMonitorRepairEbook.com for lcd monitor repair tips, diy lcd monitor repair solutions, backlight inverter, backlight replacement and ccfl inverter circuit.
Super Capacitors
One of the most critical aspects of an uninterruptible power supply (UPS) is its standby or back-up battery system, where super capacitors are now beginning to play a role.
A super capacitor resembles a regular capacitor except that it offers high capacitance in a small package. Energy storage is by means of static charge rather than an electro-chemical process, inherent in lead-acid uninterruptible power supply batteries. Applying a voltage differential on the positive and negative plates charges the super capacitor (this concept is similar to an electrical charge that builds up when walking on a carpet).
Their design makes them ideal for small uninterruptible power supply installations whereby they are being utilised in favour of a battery set or to reduce the potential for battery discharge during momentary mains power failures.
The amount of energy that can be stored depends upon the active material used in the design of a super capacitor. Potentially, it can achieve up to 30kW of stored energy.
A super capacitor (also referred to as electric double layer capacitor, electrochemical double layer capacitor or ultra capacitor) consists of two electrodes constructed from a highly activated carbon material, which may be woven. Whereas a regular capacitor consists of conductive foils and a dry separator, the super capacitor crosses into battery technology by using special electrodes and some electrolyte. There are three types of electrode materials suitable for the super capacitor: high surface area activated carbons, metal oxide and conducting polymers. The high surface electrode material, also called Double Layer Capacitor (DLC), is least costly to manufacture and is the most common. It stores the energy in the double layer formed near the carbon electrode surface.
The carbon activated electrodes provide a large reticulated area upon which an active material such as Ruthenium Oxide is deposited. The material provides an enormous area, for example, 1000 square meters per gram of material used. Cellulose paper with polymeric fibers to provide reinforcement is typically used as the separator between the electrodes. Electrolyte is usually diluted Sulphuric Acid. Ruthenium Oxide is converted into Ruthenium Hydroxide by a chemical reaction and this enables energy to be stored.
To operate at higher voltages, super capacitors are connected in series. On a string of more than three capacitors, voltage balancing is required to prevent any cell from reaching over-voltage.
Energy within a super capacitor is quickly available – and this is one of its greatest advantages. When coupled to an existing battery set, they can inhibit battery cycling for momentary interruptions, which helps extend the working life of the set. A super capacitor’s working life is typically ten years (double that of an average UPS battery). They can also operate over a wide temperature range (minus 30 to 45 degrees centigrade).
Other Advantages
- Virtually unlimited cycle life - can be cycled millions of times.
- Low impedance - enhances load handling when put in paralleled with a battery.
- Rapid charging –super capacitors charge in seconds.
- Simple charge methods - no full-charge detection is needed; no danger of overcharge.
Limitations
- Linear discharge voltage prevents use of the full energy spectrum.
- Low energy density - typically holds one-fifth to one-tenth the energy of an electrochemical battery.
- Cells have low voltages - serial connections are needed to obtain higher voltages. Voltage balancing is required if more than three capacitors are connected in series.
- High self-discharge - the rate is considerably higher than that of an electrochemical battery.
Whereas the electro-chemical battery delivers a steady voltage in the usable energy spectrum, the voltage of the super capacitor is linear and drops evenly from full voltage to zero volts. Because of this, it is unable to deliver the full charge. If, for example, a 6V battery is allowed to discharge to 4.5V before the equipment cuts off, the super capacitor reaches that threshold within the first quarter of the discharge cycle. The remaining energy slips into an unusable voltage range. A DC-to-DC converter could correct this problem but such a regulator would add costs and introduce a 10 to 15 percent efficiency loss.
The charge time of a super capacitor is about 10 seconds. The ability to absorb energy is, to a large extent, limited by the size of the charger. The charge characteristics are similar to those of an electrochemical battery. The initial charge is very rapid; the topping charge takes extra time. Provision must be made to limit current when charging an empty super capacitor.
In terms of charging method, the super capacitor resembles the lead-acid battery. Full charge occurs when a set voltage limit is reached. But unlike the electrochemical battery, the super capacitor does not require a full-charge detection circuit. Super capacitors take as much energy as needed. When full, they stop accepting charge. There is no danger of overcharge or 'memory'.
Super capacitors are relatively expensive in terms of cost per watt. Some design engineers argue that the money would be better spent providing a larger battery by adding extra cells. But the super capacitor and chemical battery are not necessarily in competition. They enhance one another.
About the Author
Robin Koffler is the General Manager for Riello UPS Ltd the UK subsidiary of Riello UPS (RPS S.p.A) a leading European manufacturer of Uninterruptible Power Supplies and a co-author of The Power Protection Guide(ISBN 978-0-9554428-0-3)- available from Amazon.com
Why capacitors are normally Installed out of Control Panel? Or Is it possible to install them inside panel?
I heard that there is normal rule in indusry, that Capacitors which are used to increase PF are kept outside control Panel.. Is it true? If yes why is it so? If I have 25 KVAR capacitors 10 Nos.? Should I install them inside control panel or outside of panel? & why?
Every capacitor I ever saw mounted, properly, has been inside a paneol, BECAUSE if your body accidentally discharges a high enough level of level of capacitance, you will probably be dead. I have seen them installed in their own enclosure, within the equipment they are a part of, with other equiopment, and in control panels.
I have limited experience with this type of thing, which means, THIS IS NOT THE PLACE TO GET A DEFINITIVE ANSWER. If it really makes a difference, talk with someone who knows what the blazes they are talking about, for crying out loud>!!
Thanks for visiting!
