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Why latching current is more than holding current in thyristor?
Wiki User
∙ 13y ago
Holding current is a kind of Imin i.e., a minimum rating current which should not be decreased less than this limit so that SCR will be off(Maximum limit).Whereas latching current is again a limit which is Imini.e., a minimum current that should be there to make it on(Minimum limit).So obviously Holding current is more than latching current.If u still have the confusion go through the link below
ALi RAZA
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∙ 13y ago
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What is conduction angle in thyristor?
not a clue a A: It all depends on the thyristor. There are no calculation involved not until you look up the thyristor specifications and decide on the load of the thyristor then you may calculate or more likely choose.
What circumstances led to the invention of the transistor in 1947?
before the invention of transistor,thyristor was used instead of transistor but thyristor produces more heat in the circuit and size is more when compared to transistor
Is there any visible difference between thyristor and transistor?
A diode is a solid state passive device that will only allow current to flow in one and only one direction (Anode->Cathode). A Thyristor behaves exactly like a Diode except that in order for current to flow it must "see" current at its gate, if it does not see current (ie logic 0 or ground) then current is not allowed to flow from its anode to cathode.Note: The Thyristor gate requires little current to trigger its gate, meaning a small amount of current can be used to switch on/off a load require much more current.Another Note: Since the Thyristor has a gate which controls its output it is not a passive device like the diode
How does led brightness vary with current?
More current = More brightness
What happens if gate voltage of an ON scr is decreased?
A: Nothing after an SCR conduct the gate has no more control to shut it off. So how do we shut off an SCR two way reverse the voltage on the SCR or reduce the current below the holding current. SCR are not DC friendly once on they stay on until see above
What is conduction angle in thyristor?
not a clue a A: It all depends on the thyristor. There are no calculation involved not until you look up the thyristor specifications and decide on the load of the thyristor then you may calculate or more likely choose.
What circumstances led to the invention of the transistor in 1947?
before the invention of transistor,thyristor was used instead of transistor but thyristor produces more heat in the circuit and size is more when compared to transistor
What are the two conditions necessary for a thyristor to begin to conduct?
There are more than two conditions that can make a thyristor conduct, but the general (functional) ones are: 1) positive voltage form anode to cathode, and 2) a positive voltage on the trigger input (referenced to the cathode) for a standard polarity thyristor. Other conditions can be: A) Anode-Cathode Voltage exceeding thyristor witholding voltage. B) Overtemperature of the thyristor chip C) Faulty thyristor (can be caused by overloads)
Is there any visible difference between thyristor and transistor?
A diode is a solid state passive device that will only allow current to flow in one and only one direction (Anode->Cathode). A Thyristor behaves exactly like a Diode except that in order for current to flow it must "see" current at its gate, if it does not see current (ie logic 0 or ground) then current is not allowed to flow from its anode to cathode.Note: The Thyristor gate requires little current to trigger its gate, meaning a small amount of current can be used to switch on/off a load require much more current.Another Note: Since the Thyristor has a gate which controls its output it is not a passive device like the diode
What does a thyristor do in a circuit?
A thyristor is a solid state three terminal electronic power switch with two power terminals which carry the operational part of the device current and one gate or trigger terminal which is used to switch on the thyristor when required.Whenever the current flowing though it changes diirection or simply falls to zero, a thyristor will switch off.Unlike a transistor, after its gate/trigger signal is removed a thyristor will remain switched on for as long as the direction of the current flowing through it remains the same, even if the amperage of that current changes.Unlike a mechanical switch the thyristor has operational supply polarities ( positive & negative of the supply ) which have to be observed. Therefore it can switch on and conduct for one supply polarity only.Since it is a solid state device a thyristor can operate at much faster switching speeds than any electro-mechanical switch.With a DC supply of correct polarity, a thyristor will conduct when triggered but will not then switch off till the current is interrupted by some other means such as removal of the supply or by use other, much more complex, circuitry which forces the current to flow in the reverse direction.With an AC supply, when triggered a thyristor will conduct when the supply is of correct polarity and will then automatically switch off when the AC supply polarity reverses.For controlled operation in both directions, using the gate as a trigger on the both the forward and the reverse part of the AC Supply, a second thyristor connected with reverse polarity has to be used in parallel with the first one. This idea is basically what is used to make AC lamp dimmers nowadays.========================================================A thyristor is a transistor having a thyratron-like characteristic; as collector current is increased to a critical value, the alpha (amplification factor) of the unit rises above unity to give a high-speed triggering action.That description just given (now shown in italics) is wrong! It is not for a thyristor but for a thermistor!A thermistor is a device with 2 wires coming out of it which changes its resistance to electrical current flow as its temperature is changed. They are used in devices that have to perform some job based on the temperature of the medium they are in.The thyristor is a solid-state semiconductor device with four layers of alternating N- and P-type material. They act as bi-stable switches, conducting when their gate receives a current pulse, and continue to conduct for as long as they are forward biased. (That is, for as long as the voltage across the device has not reversed).Some sources define silicon controlled rectifiers and thyristors as synonymous. Other sources define thyristors as a larger set of devices with at least four layers of alternating N and P-type material.========================================================Re. the error shown in italics above... The first answer at the top of the page is correct: a thyristor (aka SCR or Silicon Controlled Rectifier) is a four layer solid-state switch, and a thermistor is a temperature-sensitive device consisting of a material with a high thermal coefficient of resistance, either positive or negative.Thyristors are solid-state semiconductor devices with four layers of alternating N- and P-type material. They act as bi-stable switches, conducting when their gate receives a current pulse, and continue to conduct for as long as they are forward-biased (That is, as long as the voltage across the device has not reversed).
What is stronger holding current load a 12 gauge wire or a 14 gauge wire?
The lower gauge number is always a thicker wire which can carry more current.
What is the difference between an SCR and a TRIAC?
A thyristor is another name for an SCR, which stands for Silicon Controlled Rectifier.Thyristors or SCRs are bi-directional devices used to control the flow of AC current. Once triggered, the device remains "on" until the next wave of current crosses zero after the trigger is removed.For more information about thyristors or SCRs see the Related link shown below.
When An SCR conducts appreciable current?
And SCR will conduct appreciable current when it is gated "on" and thus "told" to conduct. A silicon controlled rectifier(SCR) is an electronically controlled DC switch, and the gate is the terminal to which the control voltage is applied. Use the link below to learn more.
What is by- election?
It's an election held for a certain seat if the current person holding the position is unable to perform their duties any more - eg they die.
What is By-election?
It's an election held for a certain seat if the current person holding the position is unable to perform their duties any more - eg they die.
Where can I learn more about holding an addiction intervention?
The question given does not need fixing. Where can I learn more about holding an addiction intervention?”
How do you turn on a silicon controlled rectifier?
In the usual circuit, a pulse of voltage on the gate electrode, providing a very small current, will cause a large current to flow from anode to cathode. The SCR will stay on until the anode current is reduced to zero (which may be because it's an AC supply). More at http://www.allaboutcircuits.com/vol_3/chpt_7/5.html ANSWER: By applying a gate current of significant magnitude the SCR will turn on, It not an amplifier it does not amplify current it just conduct with the gate current It is possible to have more gate current then current trough it, the shut off point need not be zero voltage it can be negative to the anode or the falls below the holding current
