Cisco CCNA Certification: The (Many) Different Kinds Of Switching by Chris Bryant
When you're studying for your CCNA exam, whether you're taking the Intro-ICND path or the single-exam path, you're quickly introduced to the fact that switching occurs at Layer 2 of the OSI model. No problem there, but then other terms involving switching are thrown in, and some of them can be... The process of circuit switching is just a bit different, in that the process of setting up the circuit itself is part of the process. ... The circuit-switching technology most familiar to CCNA candidates is ISDN.

CCNA Certification Exam Training: Circuit Switching vs. Packet Switching by Chris Bryant
CCNA certification exam training is all about learning the details, and an important part of your CCNA test prep is knowing the differences between Cisco router and switch technologies that are somewhat similar. Packet switching and circuit switching are both methods of getting packets from... While most packet-switching technologies are cheaper to run than most circuit-switching technologies, that cost is offset by the slight delay inherent to packet switching. ... The deciding factor between circuit switching and packet switching comes down to the tolerance for delay.

Integrated Power Management Circuits by Dan Hagopian
Discussing internal battery design would be incomplete if we did not write on the subject of integrated circuits. Batteries for PDAs, MP3s, Digital Cameras, and Laptops have designed within them integrated power management circuits that insure that the deliverance of reliable power is properly... At its most basic level an integrated circuit in general is a miniaturized electronic circuit. ... A real example of a battery pack protector circuit is a Texas Instrument two-cell lithium-ion (Li-Ion) and lithium-polymer (Li-Pol) battery pack protector device.

The Importance Of Current Sense Resistor In Switch Mode Power Supply by Jestine Yong
Current sense resistor is usually located in the switch mode power supply section. Newer version of monitor-the b+ (boost) circuit also have this current sense resistor. If you repair electronic equipment especially the switch mode power supplies, the current sensing resistor is connected to the... This circuit usually samples the voltage drop across a resistor in series with the switching fet transistor. ... Another tip is that if the current sense resistor in the monitor B+ circuit have changed value it will caused the output in the boost circuit to become low and you will have a small...

History of the Computer: Cooling, Part 1 of 2 by Tony Stockill
We have mentioned the provisions made to provide back-up power systems involving generators and banks of batteries (see history of the computer - redundancy). You can probably tell from this that we are talking about a lot of power here. Power means heat, and in the exacting world of the... For instance a resistor designed for one quarter watt dissipation in a circuit today could have been replaced by a 10 watt resistor of the same value in the tube design, and have the same effect in the circuit.

The Right Way To Discharge Capacitor In Switch Mode Power Supplies by Jestine Yong
Switch mode power supply contain some large filter capacitors that can hold dangerous charges even if the unit has not been used for several days. Typical values of this type of filter capacitor are 220uf 250volt and 330uf 400volt! If you are going to work on the power supply circuits, it's a... The reason for not using the screw driver to discharge a capacitor is because -the printed circuit board or circuitry can be damage due to the spark generated while discharging the high voltage capacitor.

Four Power System Problems Common in Colocation Facilities by Robert Deupree
The primary factor that determines uptime for servers in a colocation facility is power. Power outages will knock a network offline and even damage hardware such as motherboards, memory, and hard drives. Despite how intrinsic power is to keeping businesses connected to their networks, only 2% to... Ideally, a colocation facility should have a redundant backup generator in case the primary generator fails, and the facility should have a process in place for switching power between generators. ... Problem 3: Transfer Switch Failures Most colocation facilities use mechanical transfer...

Cisco CCNA And CCNP BCRAN Exam Training: Frame Relay PVC, SVC, DLCI, and Map Statements by Chris Bryant
In today's CCNP certification tutorial, we'll concentrate on the BCRAN exam and Frame Relay PVCs, SVC, and DLCIs in particular. There are actually two kinds of virtual circuits - Permanent Virtual Circuits (PVCs) and Switched Virtual Circuits (SVCs). ... SVCs go through a basic four-step process, and it's a lot like ISDN: Call Setup -- Just what it sounds like, the circuit between the two DTEs is created. ... The key to a successful Frame configuration is remembering that the local DLCI must be mapped to a remote IP address.

Discount Laptop Batteries by Jimmy Sturo
After buying the latest, top-of-the-line refurbished laptop, it is suggested to buy a quality laptop computer battery that will ensure that the investment performs at maximum capacity. A built-in 7600mAH Lithium-polymer battery can extend the laptop battery life up to 5~8 hours. ... First, protection circuit can prevent the battery from over-charging or short-circuit. ... Also, try to opt for a self-switching battery output voltage, 14 -24 V that is automatically switch based on different laptop model.

Digital Multimeters by Dennis Oley
Only a few decades ago, if you knew how to use a multimeter, you were probably an electronics technician or an engineer. But, today, the handy test equipment known as a Digital Multimeter should be in the toolbox of every handyperson. The multimeter is great for determining the working status of... A reading of zero indicates the circuit is closed and the circuit can conduct current. ... A multimeter can measure alternating current (AC or household current) or direct current (DC or battery current) in a live circuit.