| How to Read a Capacitor Posted: 25 Jul 2016 05:00 PM PDT Unlike resistors, capacitors use a wide variety of codes to describe their characteristics. Physically small capacitors are especially difficult to read, due to the limited space available for printing. The information in this article should help you read almost all modern consumer capacitors. Don't be surprised if your information is printed in a different order than the one described here, or if voltage and tolerance info is missing from your capacitor. For many low-voltage DIY circuits, the only information you need is the capacitance. EditReading Large Capacitors - Know the units of measurement. The base unit of capacitance is the farad (F). This value is much too large for ordinary circuits, so household capacitors are labeled with one of the following units:[1][2]
- 1 µF, uF, or mF = 1 microfarad = 10-6 farads. (Careful — in other contexts, mF is the official abbreviation for millifarads, or 10-3 farads.)
- 1 nF = 1 nanofarad = 10-9 farads.
- 1 pF, mmF, or uuF = 1 picofarad = 1 micromicrofarad = 10-12 farads.
- Read the capacitance value. Most large capacitors have a capacitance value written on the side. Slight variations are common, so look for the value that most closely matches the units above. You may need to adjust for the following:
- Ignore capital letters in the units. For example, "MF" is just a variation on "mf." (It is definitely not a megafarad, even though this is the official SI abbreviation.)
- Don't get thrown by "fd." This is just another abbreviation for farad. For example, "mmfd" is the same as "mmf."
- Beware single-letter markings such as "475m," usually found on smaller capacitors.[3] See below for instructions.
- Look for a tolerance value. Some capacitors list a tolerance, or the maximum expected range in capacitance compared to its listed value. This isn't important in all circuits, but you may need to pay attention to this if you require a precise capacitor value. For example, a capacitor labeled "6000uF +50%/-70%" could actually have a capacitance as high as 6000uF + (6000 * 0.5) = 9000uF, or as low as 6000 uF - (6000uF * 0.7) = 1800uF.
- If there is no percentage listed, look for a single letter after the capacitance value or on its own line. This may be code for a tolerance value, described below.
- Check the voltage rating. If there is room on the body of the capacitor, the manufacturer usually lists voltage as a number followed by a V, VDC, VDCW, or WV (for "Working Voltage").[4] This is the maximum voltage the capacitor is designed to handle.
- 1 kV = 1,000 volts.
- See below if you suspect your capacitor uses a code for voltage (a single letter or one digit and one letter). If there is no symbol at all, reserve the cap for low-voltage circuits only.
- If you are building an AC circuit, look for a capacitor rated specifically for VAC. Do not use a DC capacitor unless you have an in-depth knowledge of how to convert the voltage rating, and how to use that type of capacitor safely in AC applications.[5]
- Look for a + or - sign. If you see one of these next to a terminal, the capacitor is polarized. Make sure to connect the capacitor's + end to the positive side of the circuit, or the capacitor could eventually cause a short or even explode.[6] If there is no + or -, you can orient the capacitor either way.
- Some capacitors use a colored bar or a ring-shaped depression to show polarity. Traditionally, this mark designates the - end on an aluminum electrolytic capacitor (which are usually shaped like tin cans). On tantalum electrolytic capacitors (which are very small), this mark designates the + end.[7] (Disregard the bar if it contradicts a + or - sign, or if it is on a non-electrolytic capacitor.)
EditReading Compact Capacitor Codes - Write down the first two digits of the capacitance. Older capacitors are less predictable, but almost all modern examples use the EIA standard code when the capacitor is too small to write out the capacitance in full. To start, write down the first two digits, then decide what to do next based on your code:[8]
- If your code starts with exactly two digits followed by a letter (e.g. 44M), the first two digits are the full capacitance code. Skip down to finding units.
- If one of the first two characters is a letter, skip down to letter systems.
- If the first three characters are all numbers, continue to the next step.
- Use the third digit as a zero multiplier. The three-digit capacitance code works as follows:
- If the third digit is 0 through 6, add that many zeroes to the end of the number. (For example, 453 → 45 x 103 → 45,000.)
- If the third digit is 8, multiply by 0.01. (e.g. 278 → 27 x 0.01 → 0.27)
- If the third digit is 9, multiply by 0.1. (e.g. 309 → 30 x 0.1 → 3.0)
- Work out the capacitance units from context. The smallest capacitors (made from ceramic, film, or tantalum) use units of picofarads (pF), equal to 10-12 farads. Larger capacitors (the cylindrical aluminum electrolyte type or the double-layer type) use units of microfarads (uF or µF), equal to 10-6 farads.[9]
- A capacitor may overrule this by adding a unit after it (p for picofarad, n for nanofarad, or u for microfarad). However, if there is only one letter after the code, this is usually the tolerance code, not the unit. (P and N are uncommon tolerance codes, but they do exist.)
- Read codes that contain letters instead. If your code includes a letter as one of the first two characters, there are three possibilities:
- If the letter is an R, replace it with a decimal point to get the capacitance in pF. For example, 4R1 means a capacitance of 4.1pF.[10]
- If the letter is p, n, or u, this tells you the units (pico-, nano-, or microfarad). Replace this letter with a decimal point. For example, n61 means 0.61 nF, and 5u2 means 5.2 uF.[11]
- A code like "1A253" is actually two codes. 1A tells you the voltage, and 253 tells you the capacitance as described above.[12]
- Read the tolerance code on ceramic capacitors. Ceramic capacitors, which are usually tiny "pancakes" with two pins, typically list the tolerance value as one letter immediately after the three-digit capacitance value. This letter represents the tolerance of the capacitor, meaning how close the actual value of the capacitor can be expected to be to the indicated value of the capacitor. If precision is important in your circuit, translate this code as follows:[13]
- B = ± 0.1 pF.
- C = ± 0.25 pF.
- D = ± 0.5 pF for capacitors rated below 10 pF, or ± 0.5% for capacitors above 10 pF.
- F = ± 1 pF or ± 1% (same system as D above).
- G = ± 2 pF or ± 2% (see above).
- J = ± 5%.
- K = ± 10%.
- M = ± 20%.
- Z = +80% / -20% (If you see no tolerance listed, assume this as the worst case scenario.[14])
- Read letter-number-letter tolerance values. Many types of capacitors represent the tolerance with a more detailed three-symbol system. Interpret this as follows:[15]
- The first symbol shows minimum temperature. Z = 10ºC, Y = -30ºC, X = -55ºC.
- The second symbol shows maximum temperature. 2 = 45ºC, 4 = 65ºC, 5 = 85ºC, 6 = 105ºC, 7 = 125ºC.
- The third symbol shows variation in capacitance across this temperature range. This ranges from the most precise, A = ±1.0%, to the least precise, V = +22.0%/-82%. R, one of the most common symbols, represents a variation of ±15%.[16]
- Interpret voltage codes. You can look up the EIA voltage chart for a full list, but most capacitors use one of the following common codes for maximum voltage (values given for DC capacitors only):[17]
- 0J = 6.3V
- 1A = 10V
- 1C = 16V
- 1E = 25V
- 1H = 50V
- 2A = 100V
- 2D = 200V
- 2E = 250V
- One letter codes are abbreviations of one of the common values above. If multiple values could apply (such as 1A or 2A), you'll need to work it out from context.
- For an estimate of other, less common codes, look at the first digit. 0 covers values less than ten; 1 goes from ten to 99; 2 goes from 100 to 999; and so on.
- Look up other systems. Old capacitors or capacitors made for specialist use may use different systems. These are not included in this article, but you can use this hints to guide your further research:
- If the capacitor has one long code beginning with "CM" or "DM," look up the U.S. military capacitor chart.[18]
- If there is no code but a series of colored bands or dots, look up the capacitor color code.[19]
- The capacitor can also list information on operating voltages. The capacitor should support a higher voltage than the circuit you use it in; otherwise it may breakdown (possibly explode) under operation
- 1,000,000 picoFarads (pF) equals 1 microFarad (µF). Many common capacitor values are near this crossover area and could be commonly referred to using either unit designation. For example, a 10,000 pF cap is more commonly referred to as 0.01 uF.
- Although you can't determine capacitance by the shape and size alone, you can guess at a rough range based on how the capacitor is being used:
- The largest capacitors in a television monitor are in the power supply. Each one can have a capacitance as high as 400 to 1,000 µF, which can be lethal if handled incorrectly.[20][21]
- The large capacitors in an antique radio typically range from 1-200 µF.[22]
- Ceramic capacitors are usually smaller than your thumb and attach to the circuit with two pins. Used in many applications, they typically range from 1 nF to 1 µF, and occasionally up to 100 µF.[23]
- Be very careful when handling large capacitors, which can hold a lethal amount of energy when charged. Always make sure to discharge them first by using an appropriate resistor. Never short circuit them, as this could cause an explosion.
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| How to Not Get Nervous Posted: 25 Jul 2016 09:00 AM PDT If your heart is beating so loudly you can barely hear yourself think or your palms are sweaty and your mouth feels dry, you're probably nervous. Being nervous is a normal reaction that all humans have to challenging events. However, when it's paralyzing, you should find a way to minimize it. Although it's hard to shake nervousness, there are several different approaches you can take to calm your mind and regulate your emotional state. Try some of the techniques below to see what works for you. EditTrying Calming Exercises - Establish a breathing routine. Yoga practitioners around the world manipulate their breathing patterns every day in an effort to calm the mind. Long, peaceful breaths cue our minds and bodies that everything is okay. Short, harsh breaths do the opposite. By breathing correctly, you can tell your body how to feel.
- Close your eyes and slow down your breathing rate to relax your mind and your body.
- You can regulate your breath by counting to a certain number or repeating "Now I breathe in, now I breathe out."
- Go to your "happy place" or visualize success. Happy Gilmore wasn't full of it when he used a visualization technique to quell his anger before making a golf shot. You can use a "happy place" visualization to remove yourself from a place of nervousness and visit a stress-free place of happiness, whether it be a shopping mall or a deserted beach.
- Visualize yourself succeeding in the thing that is making you nervous. Positive visualizations can turn into actual successes if you truly believe that you can succeed.
- Remember to think happy thoughts and utilize your imagination to imagine positive rather than negative situations.
- Develop a mantra. A mantra is a phrase or saying that is repeated over and over either aloud or in one's mind as a meditative exercise. Come up with words that inspire or calm you and repeat them every time your nervousness starts to creep up. It can be helpful to close your eyes while chanting a mantra.
- Meditate or perform a body scan. Meditation, though difficult to master, is an awesome way to calm your nervousness. Find a quiet place, take a comfortable seat or lie on the ground, and attempt to notice your thoughts without bias or judgement.
- If you find it too difficult to entirely clear your mind, try a body scan instead where you focus your attention to one part of your body at a time.
- Start by bringing your attention to your feet and slowly scan up the body, paying attention to how you feel at each stage.[1]
- Write down your nervous thoughts. Instead of trying to banish nervous thoughts or feelings, take the time to feel them and then let them go. By writing down why you are nervous and how you are feeling, you can confront your nervousness rather than trying to ignore it altogether. Once you've written down your feelings, either throw the paper away as a symbolic gesture or keep it to consider it during the day.[2]
- Play soothing music. Make a playlist of music that soothes and calms you. When nervous feelings arise, listen to your playlist and allow yourself to sink into the music.
- Drink water. Calm your nervous system and nourish your body by drinking water. While you should always be drinking an adequate amount of water, doing so at the time you experience nervousness can be very helpful.
- Massage your temples. Close your eyes and use your middle finger to massage your temples on the side of your eyes. Your temples are pressure points and massaging them can be very relaxing and stress-relieving.
- Exercise or take up yoga and/or tai chi. Getting exercise is one of the best things you can do to reset your mind and body and relieve the jitters. If you are particularly nervous about an upcoming work presentation or a date with your beautiful neighbor, log at least 30 minutes of cardio activity per day.
- Yoga is not only a physical practice but an intensely mental practice that also teaches you to regulate your breathing. Try a yoga class or follow an at-home instruction to see if it helps calm your mind.
- Take up tai chi. Tai chi is a non-competitive series of flowing body motions that are designed to relax the body and mind and channel energy to positive outcomes.
- Make sure you are getting enough sleep and are eating a healthy diet. Your diet and sleep patterns not only affect your overall health, but they can affect your stress-level, and thus your tendency to get nervous, as well. Aim to get the recommended 8 hours of sleep per night and do your best to avoid fatty, greasy, and sugary foods.
EditApproaching Your Nervousness Rationally - Accept uncertainty. Some people have a difficult time not trying to control every aspect of their life. Release your controlling grip and tell yourself that there are some things you just can't predict. While you can steer your life in a certain direction, you'll inevitably take a few wrong turns or be thrown off course by a third party. And hey, that's ok!
- If life were all planned out, it'd be boring as all get out. It's the uncertainty that makes it worth living! If this is an issue for you, consciously put uncertainty in a positive light -- what little surprises will happily greet you today?
- Focus on the present instead of living in the past or future. What's done is done and what hasn't happened yet, well, hasn't happened. Don't stress yourself out by dwelling on an embarrassing moment or expecting one to happen.
- There is such a thing as a self-fulfilling prophecy. If you concentrate on messing up your big speech tomorrow, you might end up messing up your big speech tomorrow. Focusing on the now grounds you in what's going on and lets you keep a level head.
- Practice being comfortable in situations that make you nervous. You can't avoid everything, but by practicing being in uncomfortable situations, you can grow to ease your nerves over time. If getting up on a stage in front of a crowd is something that makes you intensely nervous, try practicing on smaller stages alone before working your way up to bigger stages.
- Foster a support group of family and friends that will help you meet those challenges with poise.
- Imagine the person who is making you nervous in a vulnerable situation. This is the old "imagine the crowd in their underwear" trick, but it can actually work! Even though your boss might be extremely intimidating, tell yourself that s/he is only just another human being. S/he too probably feels nervous at times and has been in several vulnerable situations before.
- The old adage, "Everybody poops" is an old adage for a reason!
- Prepare yourself for good days and bad days. Even if you adopt several relaxation techniques into your daily routine, there will still be days when the nervousness will win. Prepare yourself for both success and failure and take each step day by day.
EditUnderstanding the Source of Your Nervousness - Evaluate the rationality of your nervousness. Are you feeling nervous about something that you can solve or are you nervous about something beyond your control?
- If you are nervous about a possible situation rather than an actual one, tell yourself that it is beyond your control.[3] What's the point in being nervous about something that's going to happen either way? Nervous about the apocalypse coming? Easy to see that that's pointless -- how is your problem different?
- If your problem is actual and solvable, take action to find possible solutions. For example, if you are nervous about making your rent payment on time, call your landlord and ask about a potential extension.
- Let go of the idea that your nervousness has positive effects. Many people develop a routine of extreme nervousness because they think that it is doing them some good or pushing them to perform[4]. But in the end, being nervous is just time wasted that you could have spent feeling, well, almost anything else!
- Feeling nervous that a worst-case scenario is about to happen to you sometime in the near future doesn't lead to any positive outcomes. You won't be any more prepared and you'll have lost that precious time to enjoy yourself.
- Approach your nervousness rationally and don't allow your body to be controlled by nervous thoughts. Assert your rational mind and let the nervousness know who's boss. P.S. -- It's you.
- Remember that it's natural to get nervous. Try to practice self-compassion and recognize that you are bound to be nervous at some points in your life.
EditSeeking Medical Help - Recognize whether or not your nervousness is negatively impacting your life. You may be jeopardizing relationships simply as a result of your nervousness.
- If your nervousness prevents you from run-of-the-mill daily activities, you may be anxious. Being nervous when it comes to life's challenges is healthy and normal, but if you're nervous and you don't why, there may be a bigger problem at hand.
- Talk to a doctor about potential anti-anxiety medications. If your nervousness is so intense that it causes panic attacks, you may be a potential candidate for anti-anxiety medication. While anxiety medicine won't cure your tendency to feel nervous, it will ease your nervousness temporarily.
- Anti-anxiety medication may cause undesirable and dangerous side-effects, including addiction and depression. Consider these issues and exhaust other options before resorting to medication.
- Popular anti-anxiety medications include benzodiazepines, antidepressants, and beta-blockers. Ask your doctor which medication is right for you.
- Most anti-anxiety medications kick-in about 30 minutes after ingestion.[5]
- Hire a psychotherapist. Many people find it particularly helpful to talk to a professional therapist about their nervousness or anxiety. Establish whether group or individual counseling is right for you and make an appointment to speak with a therapist.
- Be aware that everybody messes up at some point. If you say or do something embarrassing in front of people, try to let it go and give yourself a break.
- Always take deep breaths and relax when nervous feelings start to arise.
- Reward yourself for successfully getting through situations that made you nervous.
- Give yourself a pep talk before hand. Say 'I can do this' ' I will not back down ', etc.
- Even if you don't feel confident, fake it. The more assertive you are in your demeanor, the more serious people will take you.
- Focus on the task at hand.
- Ask friends about what they do to not get nervous and see if they have any promising techniques up their sleeves.
- Practice eye contact with a picture of someone.
- If you are constantly feeling tense, can't control your worries, can't relax, or have trouble falling asleep, you may be experiencing anxiety[6]. Consider learning how to deal with anxiety.
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| How to Use Tinted Moisturizer Posted: 25 Jul 2016 01:00 AM PDT You're probably familiar with concealer and foundation. But, if you are overwhelmed by the new products in the makeup aisle, consider your skin's needs. If you have dry skin and don't want the heavy coverage that a foundation gives, a tinted moisturizer might be great for you. Tinted moisturizers are hydrating enough to be used on their own or as part of a simple makeup routine and they offer enough tint to correct any color imbalance in your skin. EditChoosing a Tinted Moisturizer - Distinguish between tinted moisturizer and foundation. Tinted moisturizer and foundation are both water-based products that contain moisturizing agents, oil, and pigment (to give some coverage). But, tinted moisturizers contain more moisturizing agents than foundation.[1]
- Depending on the makeup line, tinted moisturizers and foundations can be almost indistinguishable so you'll need to experiment with products.
- Decide if you should use tinted moisturizer. If you have dry skin and are looking for some coverage, consider using a tinted moisturizer. The humectants and emollients in the moisturizer will add moisture to your skin and help seal it in.[2]
- Foundation is a better choice for people with oily skin who are looking for heavier coverage.
- Choose a tinted moisturizer that matches your complexion. Try to match the tinted moisturizer shade to your face. If you're at a makeup counter, test a little on the side of your face. Or, test a little on the back of your hand. You shouldn't see any product on your skin if it blends well and matches. You should also check to see how your skin absorbs the product.[3]
- In the winter, consider using a shade that's a little darker than your your skin tone. This can add a little extra color and give you a bit of a sun-kissed look.[4]
- Check for sun protection. Many tinted moisturizers offer sun protection and list SPF protection. If you're not applying a separate sunscreen, you may want to find a tinted moisturizer that has an SPF of at least 30 and protects against both UVA and UVB rays.[5][6]
- Remember that the sunscreen protection from your tinted moisturizer will wear off within a few hours unless you reapply it or apply another sunscreen throughout the day.
- Select brushes. While you can simply rub tinted moisturizer onto your face using your fingertips, using a brush may give you more control. Consider using a duo fiber brush. This brush is small with a flat head so you can stipple or blend the tint into your skin.[7]
- Using a brush can help you achieve an airbrushed makeup look.
EditApplying Your Tinted Moisturizer - Combine your moisturizer and foundation primer. Squirt a very small amount of untinted moisturizer and foundation primer onto your fingertips. Rub your fingertips together so that the moisturizer and foundation primer are mixed together well. Dab the mixture on your cheeks and forehead so you can easily rub it into your skin. Pat the mixture onto your chin, temples, and under eyes.[8]
- Let it set on your skin for about a minute before applying your tinted moisturizer.
- Dot the tinted moisturizer on your skin. Squeeze about a pea-sized amount of tinted moisturizer onto your fingertip. Dab a bit of the tinted moisturizer on your cheeks, forehead, under your eyes and along your nose.[9]
- You could also put the tinted moisturizer wherever your skin appears discolored.
- Buff the tinted moisturizer into your skin. Take your brush and use sweeping motions to spread the moisturizer into your skin. Make lots of small circular motions as you move the brush across your face.[10]
- It may help to hold the brush near the end so that you're not guiding its movement as much.
- Blend in your lines. Use your brush to work the moisturizer right under your eyes, under your nose, and along your jaw line. Be sure to work the moisturizer down from your jawline to under your chin. This will prevent any makeup lines from being visible.[11]
- If your brush is too large to get into hard to reach places, try switching to a smaller or finer brush.
- Apply a concealer under your eyes. Use a rounded concealer brush to dip into your creamy concealer. Apply the concealer as close to your lash line as you can. Be sure to spread the concealer into the corners of your eyes and a little past the ends of your lash lines.[12]
- Applying a concealer can help make your skin a uniform color that matches your tinted moisturizer.
- Set the tinted moisturizer using a powder. To keep your tinted moisturizer in place for longer, apply a light dusting of powder over it. Dip a large powder brush into your usual powder and gently sweep it across your face. Be sure to get right under your eyes where you applied concealer.[13]
- Remember that depending on the powder you use, you'll probably get additional coverage or color so apply it lightly.
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