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An advantage to using an electromagnet is that they?
Can be turned off
An advantage to using electromagnets is that they?
Can be turned on and off.
What is one advantage of using electromagnets instead of permanent magnets?
Electromagnets can be turned off and off
What happens if an electromagnets ecectricity is turned off?
The magnetic field dies.
Why the speed is kept constant for conducting Morse test?
As my understand ...To determine the power of engine when one cylinder is cut off at same speed..
What does forced commutation mean?
The term "Forced commutation" is used when a thyristor is turned off using external components. If a thyristor is used in a DC circuit, when first turned on, it will stay on until the current goes to zero. To turn off the thyristor it is possible to use a Forced commutation circuit. The circuit creates a reverse voltage over the thyristor (and a small reverse current) for a short time, but long enough to turn off the thyristor. A simple circuit consist of a precharged capacitor and a switch (e.g. another thyristor) parallel to the thyristor. When the switch is closed, the current is supplied by the capacitor for a short while. This cause a reversed voltage over the thyristor, and the thyristor is turned off.
Turn off and turn off mechanism of thyristor?
The turn off and turn off mechanism of a thyristor can be best explained by the gate turn-off thyristor. The thyristor uses the reverse bias mechanism.
How do you comfirm thyristor condition?
A thyristor if conducting will have a very small voltage drop across if not then the rail voltage will be evident across the device
How do you use a thyristor as a diode?
A thyristor, also known as a silicon controlled rectifier, is a diode that can be turned on by application of a small gate voltage.
What is an off-state condition of thyristors?
thyristor can be turned off only by reducing the anode current belaw a certain value called holding current by abdullahi yusuf gedi
What are the necessary conditions for turning ON an silicon controlled rectifier?
A: Two conditions one the gate has current flowing trough the other is forward voltage breakdown
Why the Gate triggered method is always preferred to turn on the thyristor?
A: Because that is the controlling lead of an thyristor. .To do it otherwise it will be on-off at hi voltage only
What is the ratio of latching current to holding current?
Latching current is the current flowing between anode to Cathode when thyristor is turned on using gate pulse. If the gate pulse is removed before the required min amount of latching current value is not reached thyristor will turn off. To keep the thyristor in on state the gate pulse duration should be so adjusted that the min latching current value is reached before it ends.
What is commutation of thyristor?
the process of turning off of a thyrisror is known as commutation
What is line commutation?
i think i know this answer...line commutation is the commutation in single phase inverters/converters when there is current flow back to the source.. It can also refer to a method of turning of a semiconductor device known as a Thyristor or SCR, sometimes called natural commutation. In this method the current between the anode and cathode is interrupted or dropped to a point where the Thyristor can no longer maintain its latch or keep conducting, shutting the device off.
How does the turn off circuit on a Class B type thyristor work?
The Class B type of commutation circuit uses an LC circuit in parallel with the thyristor. During initial power up, the capacitor C charges to the supply voltage (Edc) and the thyristor is OFF. The initial charging current of the LC branch flows thru the load. When the thyristor is fired, the supply DC voltage is applied across the load, and the voltage across the LC branch goes to almost zero (the forward drop of the thyristor). Then the LC circuit enters a resonant discharge with an angular frequency of the square root of the inverse of LC product. The LC resonant cycle supplies a peak forward current thru the thyristor of Edc times the square root of C/L. This peak current must exceed the load current in order to effect the turn-off of the thyristor during the second half of the discharge resonant cycle. This peak current is usually designed to be twice the load current. The thyristor is reversed biased (and turned OFF) during the first quarter cycle of this second half of the resonant cycle - thus allowing the supply to recharge the capacitor in the LC parallel branch. Then the cycle can repeat.
What are types of thyristor?
Types of thyristor firing art
