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What do you call a diode installed across a coil with the cathode toward the battery positive?
Wiki User
∙ 6y ago
A diode connected in this way is a flyback diode or kickback diode. There are some other names that may be applied. The diode is a protection device. When power to the coil is discontinued, the electromagnetic field around the coil will collapse. The collapse of that field will induce a voltage, and this could expose circuit elements to "kickback" from the field collapse. The polarity of the induced voltage will, however, forward bias the diode, and it will conduct current for an instant. The inductive kickback of the coil will thus be damped by that diode.
Wiki User
∙ 6y ago
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How is the plus and minus voltage sign for resistance voltage drops for battery voltages and currents be determined?
The plus and minus voltage sign for resistance voltage, drops for battery voltages, and drops for currents is determined by convention. You can use whatever method you want - so long as your use is consistent, your analytical results will be correct for you.The commonly accepted convention, however, is best. This way, other people reviewing your results will not be confused unless, of course, they use an atypical convention.Electric current flow is electron flow. The battery terminal marked "negative", or the cathode, is the source of electrons, and those electrons are drawn to, and flow towards, the "positive" terminal, or anode.Consider a simple circuit, consisting of a battery in series with a resistor. Draw the battery on the left, with the anode up. Draw the resistor on the right. Connect the anode to the top of the resistor, and the cathode to the bottom of the circuit. (Actually, this is also a parallel circuit, with the battery in parallel with the resistor. It depends on how you see it, because this is a simple circuit.)Current flows out of the bottom (cathode, negative) battery terminal, into the bottom of the resistor, up through the resistor to its top, over to the left, and into the top (anode, positive) battery terminal, and down through the battery, completing the circuit at the cathode. This is counter-clockwise, if you have drawn the circuit as stated.If you place a voltmeter across the battery, you will see that the anode (top) is more positive than the cathode. If you place a voltmeter across the resistor, you will see that the top is more positive than the bottom. It does not matter if you measure across the battery or the resistor, the voltage will be the same. If you place the voltmeter across the wire on the bottom, or across the wire on the top, you will see that the voltage is zero.With the preliminaries out of the way, now to the convention.Current flow is counter-clockwise, from cathode to anode. If you were to draw a current arrow, you could draw it counter-clockwise, down through the battery and up through the resistor. You would label the first point that the current encounters (the bottom of the resistor) as negative, or minus. As the current goes through the resistor, it becomes more positive, so you would label the top of the resistor positive, or plus. Go over to the anode. That is also plus. The current is made more negative due to the battary being a source, rather than a load, so the cathode is minus.These pluses and minuses are relative to each other, and they are also relative to some common reference point, said point by convention being the cathode. In this simple circuit, there is only one point that has any voltage different than the cathode, and that is the anode, so this distinction might be vague.Consider then, the case where the resistor is actually two resistors in series. Again, the bottom resistor starts minus on its connection to the cathode, it becomes more positive as the current goes up, making the top of the bottom resistor plus. The bottom of the top resistor is minus, because current is flowing into it, and it becomes more positive as the current goes up, with the top of the top resistor plus.When you measure voltage across an element, you see the voltage for that element. If, instead, you measure the voltage relative to the common reference point, and there is more than one element between the voltmeter's leads, you add up the voltage rises or drops to figure out what to expect. In fact, this is the basis for Kirchoff's voltage law - that the signed sum of the voltage drops around a series circuit always adds up to zero.So, this preliminary convention is that current flow leaves the minus terminal of a voltage or current source, and enters the minus terminal of a voltage or current load. It then enters the plus terminal of a voltage or current source, and leaves the plus terminal of a voltage or current load.Now, to confuse you, another convention states that current flows from plus to minus, not from minus to plus. This means that current leaves the plus terminal of a source, and enters the plus terminal of a load, and it enters the minus terminal of a source and leaves the minus terminal of a load.It does not really matter which convention you use. The positions of the plus and minus signs will be the same - its just that the current arrow will point in the opposite direction - in this example, clockwise instead of counter-clockwise. What is important is to be consistent in your use of the plus or minus sign as the current enters and leaves a source or a load.The convention of current flow is arbitrary. So long as you are consistent in your application, you will get the correct results.It is generally accepted that current flow is electron flow, which means that current flows from the negative side of a voltage or current source towards the positive side.Often, however, current is considered to flow from positive to negative. While this makes perception in circuit analysis more straightforward, it does not change the analytical results.
How many volts does an AA battery produce?
A good AA battery has about 1.5 volts across it.
Two resistors are connected in parallel to a battery What must the votlage across these two resistors?
Both resistors will have the voltage of the battery.
Why does SCR turn ON by gate current?
to make the revers biased p-n junction in SCR to be conducting.when we apply gate signal across gate and cathode it establish conducting part,thus the current from anode to cathode flow i.e main current.even after we remove the gate signal SCR in conducting mode because now this conducting path is maintain by main current i.e current from anode to cathode
Describe forward bias of a diode?
When the polarity of the battery is such that electrons are allowed to flow through the diode,then the diode is said to be forward-biased. Conversely, when the battery is "backward" and the diode blocks current, then the diode is said to be reverse-biased. A diode may be thought of as like a switch: "closed" when forward-biased and "open" when reverse-biased.
How do cathode rays form?
Cathode rays are the emission of free electrons form the negative pole of an electric circuit. To get this to happen you need to warm the cathode and place it in a vacuum tube with a high voltage across it. The electron then jump form the cathode and fly across the empty tube to the anode (positive end). They may be bent by magnetic fields in flight.
I installed a new battery on my Bayou 220 1999 and there is no lights or power anywhere. Is there a fuse somewhere?
Have the new battery tested. It should read 12.68 volts across the posts. It could be dead.Did you have this condition before the new battery was installed?
Should you connect the pos or neg terminal first when replacing a car battery?
Assuming the vehicle has a negative earth You connect the positive lead first The reasoning When the positive lead is fitted first, if you dropped a spanner across the battery negative terminal to the car body all you would do is make the circuit. If you connect the Negative lead first, and you dropped a spanner across the positive battery terminal to the car body you would then have a dead short
What happens when a capacitor connected across a battery for a long time?
For a long time, The capacitor will be charged to the voltage of the DC battery, the positive side of the capacitor touching the positive terminal of the battery. Not much DC current will conduct, except for some tiny leakage current due to imperfection of the cap. The battery will be drained eventually.
Rectifier How do you change the 2 arrows direction in the circuit to make it positive or negative In Bridge?
A: Actually there is no changing of diodes required to get negative voltage out put the two cathode to ground if you have a load the voltage across will be negative. Electrons only flow in one direction where the measurement point are located across the load makes positive or negative.
What is the negatively charged electrode of a cathode ray tube?
The negatively charged electrode of a cathode ray tube (CRT) is the cathode. The tube is a cathode ray tube, and electrons stream off the cathode, are accelerated across the evacuated space and "directed" either electromagnetically or electrostatically, and then strike the phosphor coating on the positively charged anode at a "location" determined by the "directing" elements.
Are cathode rays electromagnetic waves?
Cathode rays are not electromagnetic rays because the cathode ray is a beam of electrons that travel from the negatively charged to positively charged end of a vacuum tube, across a voltage difference between the electrodes placed at each end.The electrode at the negative end is called a cathode; the electrode at the positive end is called an anode.Since electrons are repelled by the negative charge, the cathode is seen as the "source" of the cathode ray in the vacuum chamber.
How is the plus and minus voltage sign for resistance voltage drops for battery voltages and currents be determined?
The plus and minus voltage sign for resistance voltage, drops for battery voltages, and drops for currents is determined by convention. You can use whatever method you want - so long as your use is consistent, your analytical results will be correct for you.The commonly accepted convention, however, is best. This way, other people reviewing your results will not be confused unless, of course, they use an atypical convention.Electric current flow is electron flow. The battery terminal marked "negative", or the cathode, is the source of electrons, and those electrons are drawn to, and flow towards, the "positive" terminal, or anode.Consider a simple circuit, consisting of a battery in series with a resistor. Draw the battery on the left, with the anode up. Draw the resistor on the right. Connect the anode to the top of the resistor, and the cathode to the bottom of the circuit. (Actually, this is also a parallel circuit, with the battery in parallel with the resistor. It depends on how you see it, because this is a simple circuit.)Current flows out of the bottom (cathode, negative) battery terminal, into the bottom of the resistor, up through the resistor to its top, over to the left, and into the top (anode, positive) battery terminal, and down through the battery, completing the circuit at the cathode. This is counter-clockwise, if you have drawn the circuit as stated.If you place a voltmeter across the battery, you will see that the anode (top) is more positive than the cathode. If you place a voltmeter across the resistor, you will see that the top is more positive than the bottom. It does not matter if you measure across the battery or the resistor, the voltage will be the same. If you place the voltmeter across the wire on the bottom, or across the wire on the top, you will see that the voltage is zero.With the preliminaries out of the way, now to the convention.Current flow is counter-clockwise, from cathode to anode. If you were to draw a current arrow, you could draw it counter-clockwise, down through the battery and up through the resistor. You would label the first point that the current encounters (the bottom of the resistor) as negative, or minus. As the current goes through the resistor, it becomes more positive, so you would label the top of the resistor positive, or plus. Go over to the anode. That is also plus. The current is made more negative due to the battary being a source, rather than a load, so the cathode is minus.These pluses and minuses are relative to each other, and they are also relative to some common reference point, said point by convention being the cathode. In this simple circuit, there is only one point that has any voltage different than the cathode, and that is the anode, so this distinction might be vague.Consider then, the case where the resistor is actually two resistors in series. Again, the bottom resistor starts minus on its connection to the cathode, it becomes more positive as the current goes up, making the top of the bottom resistor plus. The bottom of the top resistor is minus, because current is flowing into it, and it becomes more positive as the current goes up, with the top of the top resistor plus.When you measure voltage across an element, you see the voltage for that element. If, instead, you measure the voltage relative to the common reference point, and there is more than one element between the voltmeter's leads, you add up the voltage rises or drops to figure out what to expect. In fact, this is the basis for Kirchoff's voltage law - that the signed sum of the voltage drops around a series circuit always adds up to zero.So, this preliminary convention is that current flow leaves the minus terminal of a voltage or current source, and enters the minus terminal of a voltage or current load. It then enters the plus terminal of a voltage or current source, and leaves the plus terminal of a voltage or current load.Now, to confuse you, another convention states that current flows from plus to minus, not from minus to plus. This means that current leaves the plus terminal of a source, and enters the plus terminal of a load, and it enters the minus terminal of a source and leaves the minus terminal of a load.It does not really matter which convention you use. The positions of the plus and minus signs will be the same - its just that the current arrow will point in the opposite direction - in this example, clockwise instead of counter-clockwise. What is important is to be consistent in your use of the plus or minus sign as the current enters and leaves a source or a load.The convention of current flow is arbitrary. So long as you are consistent in your application, you will get the correct results.It is generally accepted that current flow is electron flow, which means that current flows from the negative side of a voltage or current source towards the positive side.Often, however, current is considered to flow from positive to negative. While this makes perception in circuit analysis more straightforward, it does not change the analytical results.
When you have a linked 48 volt system can you use one of the 12 volt batteries as 12 volts or are they all 48 when linked?
You can pull 12 volts off of any single battery in the circuit. The output from each battery never changes, it's always 12 volts. Those batteries are wired together in SERIES to increase the final output voltage of the entire circuit to 48 volts. To demonstrate this, place a voltmeter across the positive and negative terminal of any battery in the system. It will read 12 volts, regardless of which battery you're measuring across. Now place the voltmeter from the positive terminal on one battery and the negative terminal on a different battery. Depending on how many batteries you're measuring across, it will read 24, 36 or 48 volts. Practical application - connect your 12 volt device from the positive terminal to the negative terminal on a single battery.
How does an electrolytic cell work?
A voltage applied across two electrodes causes electrons to flow
What will happen if you place a wrench across a 12volt car battery positive and negative terminals without it being connected to a vehicle?
It will throw sparks, melt a spot in the wrench at the point of contact and if it should stick, drain the battery and very likely ruin it. You do this just to check if there is juice in the battery and just for a second.
A coil of 8 ohm parallel with coil of 20 ohm This is connected in series with 12 ohm resistor If the whole circuit is connected across a battery having emf of 30V internal resistance of 2ohm whats v?
v of what? v across what? v measured from what 2 points? v across the coils? v across the resistor? v across the coils and resistor? v across the battery? v across the battery and coils? v across the battery and resistor? or are you asking what v stands for? v stands for voltage.
