Datasheet Resistor

EEVblog #176 – Lithium Ion/Polymer Battery Charging Tutorial

Author: admin

Want to include a small Lithium Ion or Lithium Ion Polymer battery into your next project? It’s easy! Dave gives you the low down on how they work and how to charge them and select a suitable charging IC. NOTE: For safety you should always use circuit protected cells as per the larger cell I was holding up. It protects against over-discharge, over-voltage, shorts etc. (BTW, the reference to Lithium Ion Polymer being the same as Lithium Ion is in terms of charging, if that was not clear. The Ion Polymer type have polymer anode material and hence a different construction that allows the small pouch type cells shown in the video, and other thin odd shapes shown toward the end)

Flanged Bearing Computer Internet Security Software

Tags: affection, Battery, Breier, Charging, Director, EEVblog, IonPolymer, Lithium, PrimeSense, Shvueli, Tutorial
January 12th, 2012  |  Posted in Datasheet Resistor  |  Comments Off

Basic electronics : resistors (learning electronics) (electronics tutorials)

Author: admin

www.theelectronicsbook.com Resistor is a component that resist to current flow though it. The resistor obey to ohm’s law, this is the reason that the resistor is using for tuning currents in the electronic circuit. The resistor is one of the most common components in the circuit. The resistance of each resistor is calculated and defined by the circuit designer according to the required currents and voltages in the circuit. Each resistor is manufactured with a specific resistance. Manufacturers have a large range of resistors on almost every resistance value according to some important rules. Theoretical calculation in the electronic circuit can defines the resistance of the resistor. Let’s say that the resistor that we calculated is 10.2378Ω. The resistor component has a specific resistance but it is impossible for the manufacturer to generate every required resistance. The manufacturer has a table with available values of resistors that the customer can buy. You should buy the closest resistor value to your calculations. The manufacture process of resistor (and every electronic component) is a complex process that can not generate an exact value. This is the reason that the manufacturer defines the accuracy of the resistor. Example the manufacturer sells a resistor of 10KΩ with accuracy of 10%. The manufacturer is committed to a resistance value between 9KΩ-11KΩ. The circuit designer must take this range in account when using this resistor. If you want a better accurate …

Compact Flash Memory Cards

Tags: electronics, learning, resistors, tutorials
January 4th, 2012  |  Posted in Datasheet Resistor  |  Comments Off

Troubleshooting And Repair Power Supply The Easy Way

Author: admin

Troubleshooting linear power supply was quite easy as compare to switch mode power supplies (SMPS). AC voltage enters to the primary side of linear transformer and then converted the AC into a lower or higher AC voltage depending on the secondary winding. The output AC voltage is then rectified and filtered by a diode and capacitors to produce a clean DC voltage. If there is a problem in the linear transformer circuit, I can say that it is very easy to locate the fault. This is somehow different in the case of a switch mode power supply. The designs were complicated and some technicians found it quite hard to fully understand how the switch mode power supplies work.

The working principle of switch mode power supply is different from the linear type. First the AC voltage will flow to a full wave rectifier (bridge rectifier) which produces an uneven DC output and then filtered by a large capacitor (usually 220 micro farad and up to 450 volts). The clean DC voltage will then flows to start up resistors and to the input of switch mode power transformer. Once the voltage passed through the high ohms resistor (start up resistors) the voltage would drop to a value where it then flows to the VCC supply pin of Pulse width modulation IC.

Once the PWM IC received the voltage it will output a signal to drive the transistor (or FET) and produces a changing in magnetic field in the transformer primary winding. The changing magnetic field induces voltage in the secondary windings. Each of these AC voltage produced by the secondary windings is then rectified, filtered, and regulated to produce a clean DC voltage. One of the main DC output voltage is the B+ that supply to flyback transformer (for TV and Monitor Circuit)

The output from the B+ voltage supply is then connected, through a “feedback” loop (which consist of optoisolator ic and an error amplifier TL431 IC), back to the PWM IC. When the voltage from the B+ supply rises or drop a bit, the PWM IC will act to correct the output.

If you still do not understand the above explanation, please do not be discourage because you can always buy technical books and schematic diagrams and read it till you get the whole idea of how a SMPS work. You can ask a repair friend or even surf the internet for a better and easy explanation.

Here I would like you to download a free SMPS article by Sencore and I found it to be a great help for you who are still struggle on how SMPS work and how to troubleshoot when it fails. You must ask your self what is the purpose and its function of the components in the SMPS circuit and how to check them if they fail. Find out on your own the function of these components in SMPS circuit:

Bridge rectifier,

Filter capacitor,

Start up resistors

Chopper/Power FET

Pulse Width Modulation (PWM IC)

Current sense resistor

Switch mode power transformer

Optoisolator/optocoupler

Error Amplifier IC (TL431)

Secondary diodes

Secondary filter capacitors

Push yourself further by searching the internet for the datasheet of a PWM IC part number. For example, UC3842 PWM IC is mostly used in SMPS. Do you know what the function of pin 5 of this IC is? Do you know which pin the VCC supply enters? Do you know what the actual voltage that flow to the IC is? Do you know which pin that drives the power FET? Can I get a replacement for this IC? And so on………

Let’s take a soldier as an example. Soldiers not only good in handling rifle but also knows all the details about it. They know how to dismantle and assemble back their rifle fast (imagine in the middle of war the rifle jammed-they can repair it fast). They know how much each bullet cost, how far the shooting distance, how big is the diameter of the bullet, how many cm the length of the bullet and so on. Hope you don’t get bored with the soldier’s story, did you get the ideas?

Any SMPS that comes across my repair bench, I would not immediately repair it, in fact I will take couples of minutes to analyze the circuit design and see it from all angles before I begin to repair. Troubleshooting SMPS is not limited to only one procedure in fact many electronic repairers have their own unique ways and methods to solve SMPS problems. Some prefer to use light bulb to isolate SMPS faults while others like to use resistors. Troubleshooting SMPS is fun and flexible but in some cases could make you get very frustrated too.

Remember, don’t limit yourself to only one or two sources to get you understand and be able to repair SMPS. If you have the budget, get the books that have related to SMPS repair-study and start doing practical about it. Share your problems with other fellow electronic repairers and the most important thing is don’t give up. There’s lot of mountain in the journey of our live and you yourself have to climb and conquer it. All the best!

Massage Chair

Tags: Repair, Supply, Troubleshooting
December 31st, 2011  |  Posted in Datasheet Resistor  |  Comments Off

Vishay-Dale 000 ohm Surface Mount Thick Film Resistor 0603 1/10W CRCW0603 (Continuous strip of 200)

Author: admin

Vishay-Dale 000 ohm Surface Mount Thick Film Resistor 0603 1/10W CRCW0603 (Continuous strip of 200)

Vishay-Dale 000 ohm Surface Mount Thick Film Resistor 0603 1/10W CRCW0603 (Continuous strip of 200) Feature

• Resistance: 000 ohms
• Case Type: 0603
• Wattage: 1/10 watts

Vishay-Dale 000 ohm Surface Mount Thick Film Resistor 0603 1/10W CRCW0603 (Continuous strip of 200) Overview

Vishay-Dale 000 ohm Surface Mount Thick Film Resistor 0603 1/10W CRCW0603 RoHS (Continuous strip of 200)

Vishay-Dale 000 ohm Surface Mount Thick Film Resistor 0603 1/10W CRCW0603 (Continuous strip of 200) Specifications

Available at Amazon Check Price Now!

*** Product Information and Prices Stored: Apr 24, 2011 10:18:41

Tags: (Continuous, CRCW0603, Premier, Resistor, Surface, VishayDale, Weight
April 23rd, 2011  |  Posted in Vishay-Dale  |  Comments Off