Can I replace a certain value capacitor with the same value but higher voltage? For example, if a circuit calls for a 25uF 25V can I use a 25uF 35 or 50 volt?
Capacitors are easy. Resistors are easy. Right? But then if you go below the surface there are dozens of specs for each beyond capacitance, resistance, voltage rating. These affect performance to a greater or lesser degree.So for caps, here are some things to be aware of-(Capacitance you know - check)(Voltage rating - bully for you, you're on top of it)ESR, equivalent series resistance - generally if you are not changing the chemical/physical architecture of the capacitor (electrolytic, ceramic, polypropylene, tantalum, etc.) higher voltage rating tends toward higher ESRTemperature coefficient - be aware that all caps and resistors drift in fundamental property (capacitance or resistance respectively) with temperature above or below rated temperature which is 25C usually.Polarity - some types have polarity (electrolytic, tantalum, e.g.) and some don't (ceramic, e.g.)Chemical/physical type - don't replace a cap in a design with a different type without giving it a lot of thought - we have different types for lots of reasons - read “Art of Eelctronics” if you want to be a masterHere is a little treatise on types:Ceramic -non-polarizedceramic layers as dielectricvery stablecompactlow ESRusually smaller capacitance, but now up to 100 uF is not uncommondecoupling and signal integrity applications typicallyFilm (PET,PEN,PPS PP) -non-polarized(metallized, not always) polymer film as dielectricvery low ESRfairly stable, can "self-heal" after breakdowntypically lower capacitance values than polarized capsgood for high frequency circuits where ESR can be a problemrelatively costly(special class of PP "power capacitors" big ones for high power apps)Electrolytic (aluminum, tantalum, niobium) -polarizedwet or dry electrolyte, wet are least stablenot very stable (poor)high capacitance values, especially aluminumgood for filtering power supplies, handling lots of current without much need for precise capacitanceUltracapacitors or Supercapacitors -ludicrous high capacitance, up to 1000s of Faradsapplications include buffering with high current draws and short discharge times - easing transient loads on the ultimate supplygood ESRcostly, but if you need them, you need themRespectfully,jack
What is the use of a ceramic capacitor?
Ceramic capacitor is made up of ceramic material which acts as a dielectric material for it.Ceramic capacitors are available in small values such as in micro,milli,nano,pico farads.Capacitors store energy in the dielectric, NOT in the conductive plates. Only two things determine a capacitor's effectiveness: its physical dimensions (plate area and distance separating them), and the dielectric constant of the insulating between the plates. More area means a bigger field, closer plates mean a stronger field (since field strength is measured in Volts per meter, so the same difference of potential across a much smaller distance yields a stronger electric field).The dielectric constant is how strong a field will be generated in a specific medium.Ceramic capacitors are able to store small energy.Ceramic capacitors are often used for radio frequency and in some audio applications. Generally the ceramic capacitors are small and are not constructed with an internal coil; this is why they are preferred in the high frequency applications. They are usually used in circuits which circumvent high frequency signals to ground.
Is it OK to replace an aluminum electrolytic capacitor with a ceramic multi-layer capacitor in a clock radio?
Ceramic capacitors have better high frequency characteristics than aluminum capacitors. Usually this means that replacing aluminum with ceramic improves the circuit performance at those frequencies. The exception is when the engineer relies on the poor performance to stabilize a feedback loop, which used to happen a lot in certain power supply designs.Try it. If it squeals, put an ohm or so of resistance in series with it.Also, check the voltage rating. A ceramic standing in for an aluminum might see more of an inrush surge when the device turns on.
What is the main difference between a polar and non-polar capacitor (except having poles or not)? Where do we use them?
The main difference is what they're made of. Incidentally, that also determines how big they have to be for a given capacitance, and how much they cost.Polar capacitors are also known as electrolytic capacitors, because they use an electrolyte as the dielectric. It allows for extremely high capacitance with some small leakage current in a small package. A ceramic capacitor with equivalent capacitance would have to be very, very large.There are lots of different kinds of non-polar capacitors. The two most common ones I've seen are ceramic and mica. Ceramic is cheap, mica is more expensive, but I believe mica capacitors can take a higher voltage. Altogether, they offer lower leakage current than electrolytics but also lower capacitance per size. The main advantage is that they maintain their capacitance with bias in both directions.Electrolytic capacitors are useful in places where the voltage will never switch polarity on them under proper use conditions. Their high capacitance means they can be used more effectively for power supply filtering, reducing ripple in a rectifier, and softening on/off switching.But for component decoupling, they aren't so good because without a very good bias, they'll end up with a voltage applied backward, and under backward voltage they break down, lose their capacitance and leak like crazy.They also let out the "magic smoke" when reverse biased too high. Non-polar capacitors don't.
Can we use ceramic instead of electrolytic capacitor?
CapacityElectrolytic capacitors have a large capacity, which means they can accumulate a large amount of energy. Ceramic capacitors are typically small and have small energy storage capacities.ApplicationsElectrolytic capacitors are typically used in power supply applications for voltage filtering, but are also used frequently in audio frequency amplifiers. Ceramic capacitors are often used for radio frequency and in some audio applications. Generally the ceramic capacitors are small and are not constructed with an internal coil; this is why they are preferred in the high frequency applications. They are usually used in circuits which circumvent high frequency signals to ground.now you can choose according to your convinience
Which phone was first to come with non-removable battery?
The apple iPhone , as a cellphone , was the first one to make an impact for having a non removable phone , the battery contacts were also soldered to the logic board for the first models . Now I am not sure if it is THE first phone , that could be attributed to one of the army field phones if I'm not mistaken from the 1950s or 60s that used capacitors and a hand crank to start the power charge . There may have been other cell/mobil phones before the iPhone but none made an impact with change made to the industry eventually like the iPhone . Its non removable battery was panned by many in the tech press as people were used to just buying a spare and popping one in when the other died . Some still hold true to this practice .
How can a single phase motor be reversed?
Alternating current motors are either induction start-induction run, capacitor start-induction run, or capacitor start-capacitor run motors. AC motors may be single voltage or dual voltage motors with one or two run windings respectively. The run windings on dual voltage motors, i.e., 110/220 volt motors, are connected in parallel or series depending on the system voltage. The direction of rotation of an AC motor depends on the magnetic polarity of the start winding. Reversing the polarity of the "Start" winding, in relationship to the "Run" winding, reverses the direction of rotation of all single-phase alternating current (AC) motors.
Pleasssse i need help!!!! :( :(?
"do we use a voltmeter or an ammeter to measure the electricity produced?" ....._ . _ . _ ----| |_| |_| |----- | .....................| Volt meter >> across coil measures voltage ....._ . _ . _ ----| |_| |_| |----- amp meter >> in series with coil measures current.
What's the difference between resistance and impedance?
In AC circuits, "impedance" generalizes "resistance" by Anon User is a sensible statement giving the angle they are trying to get at, but slightly misleading in my opinion, i would personally say people use Resistance to generalise Impedance.I would like to clarify further the differences for you, in a more simplistic way, this helped me understand fundamental principles early.Resistance is the opposition of electrical current flow.Resistance occurs in AC & DC circuits.In addition to Resistance, AC circuits also exhibit Reactance.Reactance is also the opposition to electrical current flow.By its very nature a DC circuit will not exhibit any form of Reactance, therefore opposition to current flow will always be measured in Resistance.Reactance exists in two forms, Capacitive & Inductive.the combination of Reactance & Resistance is called ImpedanceImpedance can therefore be thought of as the opposition of electrical current flow in a AC circuit.Due to the nature of AC circuits Reactance is always present (even if only in infinitesimal amounts)Any measurement of the opposition of current flow in an AC circuit will always be measured in Impedance.Impedance & Resistance are both measured in Ohms, and are interchangeable in many electrical formulas in practice i.e, Ohms Law.As a simplistic general view, Impedance can be thought of as Resistance in an AC circuit.Hopefully this will help understand principally the difference, albeit slightly misleading again, but the point is to understand the difference not the reasons behind.Why these differences occur is another question and with a significantly more technical answer ;-)Hope this helps.