Suntan Specifying in Quartz Crystal

February 12, 2011 Views
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Variable Electrical parameters are those that the Design Engineer must specify when selecting a Quartz Crystal device for any particular application.

a. Package Type: Will the package be Through Hole or Surface Mount, and are there size constraints with either.

b. Frequency

c. Load Capacitance: The specified Load Capacitance is dependent on the Resonance Mode required in the application . For Series resonance, no Load Capacitance is required. For Parallel Resonance, the Load Capacitance specified by the Design Engineer will be used to calibrate the Quartz Crystal thereby effecting the major operating characteristics of the device, including initial Frequency Tolerance.

d. Frequency Tolerance: At 25 degree Celsius, an amount of initial frequency deviation acceptable for the application is required. Tighter specifications of Frequency Tolerance lower yield in Quartz Crystal Blank production thereby serving to increase production costs.

e. Stability: Over the Operating Temperature Range, an amount of total deviation acceptable for the application. Tighter specifications of Stability lower yield in Quartz Crystal Blank production thereby serving to increase production costs.

f. Operating Temperature: Standard Operating Temperature ranges are generally considered as -20-+70 degrees Celsius (considered "commercial" Operating Temperature), and -40-+85 degrees Celsius (considered "Industrial" Operating Temperature) Other Operating temperature ranges are available and should be specified .

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Suntan will attend Electronic Americas 2011

January 17, 2011 Views
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Suntan Technology Company Limited will attend Electronic Americas 2011 in Sao Paulo, Brazil from March 28th to April 1st, 2011

  • Fair name: Electronic Americas 2011
  • Add.: Sao Paulo, Brazil
  • Date: March 28th to April 1st, 2011
  • Booth No.:N150

On this exhibition, all products will be presented, like metalized polyester/ polypropylene film capacitor including X2 capacitor, MLCC and high voltage ceramic capacitor, aluminum electrolytic capacitor, trimming potentiometer, varistor and rectifier diode.

Welcome to visit our booth to establish or expand our business!

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Rectifier diode SMD Rectifier M1-M7

January 13, 2011 Views
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Capacitors in Series Circuits

December 23, 2010 Views
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Capacitance can be decreased in a circuit by capacitors in series as shown in the following diagram:

We know that capacitance of a capacitor can be decreased by placing the plates further apart. Connecting two or more capacitors in series in effect increases the distance between the plates and thickness of the dielectric, thereby decreasing the amount of capacitance.

The following is the formula for calculating total capacitance in a circuit containing two capacitors in series:
                                                 
CT = (C1 x C2x C3) / (C1 + C2+ C3)

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What About Capacitance Meters?

December 16, 2010 Views
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Simple capacitance scales on DMMs just measure the capacitance in uF and do not test for leakage, ESR (Equivalent Series Resistance), or breakdown voltage. If the measurement comes up within a reasonable percentage of the marked value (some capacitors have tolerances that may be as much as +100%/-20% or more), then in many cases, this is all you need to know. However, leakage and ESR frequently change on electrolytic as they age and dry out.

Many capacitance meters don't test anything else but are probably more accurate than a cheap DMM for this purpose. A meter of this type will not guarantee that your capacitor meets all specifications but if it tests bad - very low - the capacitor is bad. This assumes that the test was made with the capacitor removed (at least one lead from the circuit - otherwise other components in parallel can affect the readings.

To more completely characterize a capacitor, you need to test capacitance, leakage, ESR, and breakdown voltage. Other parameters like inductance aren't likely to change on you.

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Resistor circuits

December 11, 2010 Views
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A varistor is an electronic component with a significant non-ohmic current-voltage characteristic. The name is a portmanteau of variable resistor. Resistors are the most widely used components in electronic circuits. Although very simple in concept they are key to the operation of many circuits. They can be used in a variety of ways to produce the required results.

When designing or building an electronic circuit, it may be necessary to use two or more resistors instead of one. Either the correct value of resistor may not be available, or it may be necessary to dissipate a higher power than that which a single resistor can dissipate on its own.

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Safety Standard Recognized Capacitor

November 22, 2010 Views
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Capacitors may retain a charge long after power is removed from a circuit; this charge can cause dangerous or even potentially fatal shocks or damage connected equipment.  Service procedures for electronic devices usually include instructions to discharge large or high-voltage capacitors. Capacitors may also have built-in discharge resistors to dissipate stored energy to a safe level within a few seconds after power is removed.

Our Suntan has produce a Safety Standard Recognized Capacitor ,It’s specifications is descriped its function detailedly as follows.

Safety Standard Recognized Capacitor - Y Pictures

Safety Standard Recognized Capacitor - Y

Safety Standard Recognized Capacitor - Y Specifications
Operating Temperature Range -25°c to +85°c
capacitance range 100pf to 10000pf
capacitance tolerance ±10%, ±20%, +80-20%
rated vlotage ac 125v, 250v, 400v
temperature cofficient ±10% for b (y5p), +30to-80% for fy (y5v)
dissipation factor (tan δ) b: 2.5% max. at 20°c and 1 khz, 1±0.2vrms.
dielectric strength 1500 vac for 60 seconds. (250vac) & 4000 vac for 60 seconds. (400vac)

If you want to have a full knowledge about Safety Standard Recognized Capacitor,please visit  www.suntan.com.hk   and have a view.

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Capacitor and trimming potentiometer make Suntan Technology high revenue

June 14, 2010 Views
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Su Suntan Introduce What is Farad

March 10, 2009 Views
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Suntan Technology Company Limited
---All kinds of Capacitors

A capacitor's storage potential, or capacitance, is measured in units called farads. A 1-farad capacitor can store one coulomb (coo-lomb) of charge at 1 volt. A coulomb is 6.25e18 (6.25 * 10^18, or 6.25 billion billion) electrons. One amp represents a rate of electron flow of 1 coulomb of electrons per second, so a 1-farad capacitor can hold 1 amp-second of electrons at 1 volt.

A 1-farad capacitor would typically be pretty big. It might be as big as a can of tuna or a 1-liter soda bottle, depending on the voltage it can handle. For this reason, capacitors are typically measured in microfarads (millionths of a farad).

To get some perspective on how big a farad is, think about this:

  • A standard alkaline AA battery holds about 2.8 amp-hours.
  • That means that a AA battery can produce 2.8 amps for an hour at 1.5 volts (about 4.2 watt-hours -- a AA battery can light a 4-watt bulb for a little more than an hour).
  • Let's call it 1 volt to make the math easier. To store one AA battery's energy in a capacitor, you would need 3,600 * 2.8 = 10,080 farads to hold it, because an amp-hour is 3,600 amp-seconds.

If it takes something the size of a can of tuna to hold a farad, then 10,080 farads is going to take up a LOT more space than a single AA battery! Obviously, it's impractical to use capacitors to store any significant amount of power unless you do it at a high voltage.

Applications

The difference between a capacitor and a battery is that a capacitor can dump its entire charge in a tiny fraction of a second, where a battery would take minutes to completely discharge. That's why the electronic flash on a camera uses a capacitor -- the battery charges up the flash's capacitor over several seconds, and then the capacitor dumps the full charge into the flash tube almost instantly. This can make a large, charged capacitor extremely dangerous -- flash units and TVs have warnings about opening them up for this reason. They contain big capacitors that can, potentially, kill you with the charge they contain.

Capacitors are used in several different ways in electronic circuits:

  • Sometimes, capacitors are used to store charge for high-speed use. That's what a flash does. Big lasers use this technique as well to get very bright, instantaneous flashes.
  • Capacitors can also eliminate ripples. If a line carrying DC voltage has ripples or spikes in it, a big capacitor can even out the voltage by absorbing the peaks and filling in the valleys.
  • A capacitor can block DC voltage. If you hook a small capacitor to a battery, then no current will flow between the poles of the battery once the capacitor charges. However, any alternating current (AC) signal flows through a capacitor unimpeded. That's because the capacitor will charge and discharge as the alternating current fluctuates, making it appear that the alternating current is flowing.

In the next section, we'll look at the history of the capacitor and how some of the most brilliant minds contributed to its progress.

Su Suntan Capacitor Circuit

March 10, 2009 Views
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In an electronic circuit, a capacitor is shown like this:

electrical circuit

©2007 HowStuffWorks

When you connect a capacitor to a battery, here's what happens:

capacitor connected to a battery

  • The plate on the capacitor that attaches to the negative terminal of the battery accepts electrons that the battery is producing.
  • The plate on the capacitor that attaches to the positive terminal of the battery loses electrons to the battery.

Once it's charged, the capacitor has the same voltage as the battery (1.5 volts on the battery means 1.5 volts on the capacitor). For a small capacitor, the capacity is small. But large capacitors can hold quite a bit of charge. You can find capacitors as big as soda cans that hold enough charge to light a flashlight bulb for a minute or more.

Even nature shows the capacitor at work in the form of lightning. One plate is the cloud, the other plate is the ground and the lightning is the charge releasing between these two "plates." Obviously, in a capacitor that large, you can hold a huge amount of charge!

Let's say you hook up a capacitor like this:

Here you have a battery, a light bulb and a capacitor. If the capacitor is pretty big, what you will notice is that, when you connect the battery, the light bulb will light up as current flows from the battery to the capacitor to charge it up. The bulb will get progressively dimmer and finally go out once the capacitor reaches its capacity. If you then remove the battery and replace it with a wire, current will flow from one plate of the capacitor to the other. The bulb will light initially and then dim as the capacitor discharges, until it is completely out.

In the next section, we'll learn more about capacitance and take a detailed look at the different ways that capacitors are used.

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