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Capacitors Explained - The basics how capacitors work working principle

WEBVTT
Kind: captions
Language: en

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Hey there guys.
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Paul here from TheEngineeringMindset.com.
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In this video, we're going to go look at the capacitors
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to learn how they work, where we use them,
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and why they are important.
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Remember, electricity is dangerous and can be fatal.
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You need to be qualified and competent
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to perform any electrical work.
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Do not touch the terminals of a capacitor,
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as it can cause an electric shock.
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So what is a capacitor?
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A capacitor stores the electrical charge.
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It's a bit like a battery,
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except that it stores energy in a different way.
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Can't save as much power as battery,
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though it can charge and release its energy much faster.
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This is very useful, and this is why you will find capacitors
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used on almost every circuit board.
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So how does the capacitor work?
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I want you to first think of a water pipe
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with water flowing through it.
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The water will continue to flow until we close the valve,
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then no water can flow, however, if after the valve,
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first we let the water flow into a tank,
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then the tank will store some of the water
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but we will continue to receive water flowing from the pipe.
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Now when we close the valve,
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the water will stop spilling into the tank
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but we still get the steady supply
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water out until the reservoir empties.
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Once the tank is filled again,
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we can open and close the valves whenever we like.
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As long as we don't completely empty the tank,
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we will get an uninterrupted water supply outside
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the last of the pipe.
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So we can use a water tank to store water
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and smooth outages in supply.
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In electric circuits, the capacitor acts as a water tank
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and saves energy.
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May release this soothe outages
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to supply.
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If we were to turn a simple circuit and turn it off too soon
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without a capacitor, then the light will turn on,
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but if we connect a capacitor to the circuit,
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then the light will remain on during interruptions,
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at least for a short duration,
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because the capacitor is now discharging
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and circuit power.
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Within a basic capacitor,
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we have two metal conductive plates,
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which are usually made of aluminum or aluminum,
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and these shall be separated
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from a dielectric insulator materials such as ceramic.
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Dielectric means the material will be polarized
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when you are in contact with an electric field,
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and we'll see what that means soon.
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One side of the capacitor is connected
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on the positive side of the circuit,
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and the other is related to the negative.
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On the capacitor side,
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you will see a bar and a symbol.
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This will indicate which side is negative.
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If we were to connect a capacitor for a battery,
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the voltage will push the electrons
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from the negative terminal above the capacitor.
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The electrons will be built into one plate of the capacitor,
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while the other plate, in turn, emits some electrons.
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Electrons cannot pass through the capacitor
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due to the insulating material.
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Finally, the capacitor is the same voltage as the battery
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and no more electrons will flow.
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Now there is a rise of electrons to one side.
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This means that we have saved energy
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and we can release this when needed.
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Because there are even more electrons on one side compared
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on the other hand, and the electrons are negatively charged,
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it means we have one that is negative
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and one side which is positive,
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so there is a change in potential,
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or a change of tension between the two,
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and we can measure this with a multimeter.
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The tension is like pressure.
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When we measure pressure, we are measuring change
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or the possible difference between the two points.
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If you imagine a pressurized water pipe,
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we can see the pressure using a pressure gauge.
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The pressure gauge is comparing two different points, too:
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the pressure inside the tube is compared
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at atmospheric pressure outside the pipe.
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When the tank is empty, the meter reads zero
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because the pressure inside the tank is now equal
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pressure outside the tank,
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thus the gauge has nothing to compare against;
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both are the same pressure.
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Same thing with tension, we are comparing difference
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between the two points.
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If we measure with a 1.5 volt battery,
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then we read a difference of 1.5 volts between each end,
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but if we measure the same end, then we read zero
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because there is no difference and it will be the same.
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Returning to the capacitor, we measure beyond
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and read a difference voltage between the two
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due to the uplift of electrons.
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We still get this reading
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even when we disconnect the battery.
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If you remember, with magnets,
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the opposites draw and pull towards each other.
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The same thing happens with construction
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of negatively charged electrons.
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They are attracted to positively charged particles
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of their atoms on the opposite plate.
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They can never get to each other
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This pull between the two sides is an electric field,
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which holds electrons in place until another path is made.
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If we then put a small lamp in the circuit,
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a path now exists for the flowing electrons
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and reach the opposite side.
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So the electrons will flow through the lamp, powering it,
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and the electrons will reach the other side
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of the capacitor.
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This will only last a short duration, though,
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until the creation of electrons equals on each side.
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Then the voltage is zero.
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So there is no driving force and no electrons will flow.
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After we reconnect the battery,
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the capacitor will start charging.
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This allows us to cut off the power supply
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and the capacitor that will provide electricity
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during these outages.
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So where do we use capacitors?
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They look a little different but they are easy to see.
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On county boards, they tend to look something like this,
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and we see them represented in engineering drawings
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with symbols like these.
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We can also get larger capacitors,
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which are used, for example, in induction motors,
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ceiling fans, and air conditioning units.
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We can have even bigger,
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which are used to correct the weak energy factor
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in large buildings.
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On the side of the capacitor, we will find two values.
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These are capacity and voltage.
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We measure the capacity of the capacitor in units
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of Farads, which we denote with a capital F,
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though we would usually measure a capacitor in the microfarads.
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With microfarades, we just have a symbol before that,
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which looks like something a U-tail letter.
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The other value is our tension,
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which we measure volts, with a capital V.
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In the capacitor, the value voltage is the maximum voltage
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which the capacitor can handle.
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We have covered the tension in detail in a separate video.
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Check it out, the link is down.
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As I said, the capacitor is rated
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to handle a given voltage.
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If we overcame this, then the capacitor would explode.
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Let's see it in slow motion.
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Eh, very good.
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So why use capacitors?
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One of the most common applications of capacitors
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in large buildings it is for power factor correction.
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When many inductive loads are placed on a circuit,
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current and voltage waveforms will fall out of sync
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with each other and the current will remain behind the tension.
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We then use capacitor banks to counter this
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and bring both back to the lining.
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We have covered the power factor before in great detail.
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Another very common application is to smooth the peaks
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when converting AC energy to DC.
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When using a full bridge rectifier,
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the AC sinus wave is sliding
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to make the negative cycle flow in a positive direction.
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This will trick the county into thinking
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it's getting direct power, but one of the problems
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with this method it is gap between the peaks.
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But as we saw before, we can use a capacitor
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to release energy into the circuit
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during these outages,
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and this will calm the power supply
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look more like a DC supply.
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We can measure capacity
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and voltage stored using a multimeter.
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Not all multimeters have the capacity function,
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but will leave a link down
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for the model I personally use.
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You have to be very careful with capacitors.
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As we now know, they conserve energy
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and can maintain high voltage values for a long time,
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even when disconnected from a circuit.
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To control the voltage, we switch to DC voltage on our meter,
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and then we hook up the red wire
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on the positive side of the capacitor
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and the black wire on the negative side.
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If we get a reading of a few volts or more,
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then we need to download it
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securely connecting terminals to a resistor
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and keep reading the tension.
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We want to make sure it is downsized
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in millivolts range before its treatment,
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or else we might have a shock.
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To measure capability, we simply change the meter
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to the capacitor function.
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We connect the red wire to the positive side
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After a short delay, the meter will give us a reading.
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We will probably get a reading close to the stated value
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but not correct.
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For example, this is estimated at 1,000 microfarads,
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but when we read it, we get a measurement of about 946.
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This is estimated at 33 microfarads,
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but we measure it, we get about 36.
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Okay, guys, this is this video,
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but to continue your teaching,
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then check out one of the videos on screen now
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and I'll take you there for the next lesson.
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Don't forget to follow us on Facebook, Twitter, Instagram,
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and of course, TheEngineeringMindset.com.

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