0
A SCR's (Silicon Controller Rectifier) name hints at the answer. As a rectifier (diode) current can only pass in one direction. There are devices at can pass in both directions, and typically they are a pair of SCR's wired in opposite polarity.
Wiki User
∙ 11y ago
Wiki User
∙ 11y agobecause it can conduct only in one direction
Add your answer:
Earn +20 pts
How many terminal leads does an SCR have?
A SCR or THYRISTOR has three leads, an anode and a cathode and the gate. It is a gate controlled diode which turns on once the gate voltage is reached and remains on until the current flowing through it is shut off. (either by another device or by an ac voltage across it passing though zero.) Large SCR's sometime have an extra lead but this is connected to the anode or cathode.
How do you control firing angle of scr?
By controlling the amount of gate current !!
Can you use a SCR instead of a relay to control output wattage of a heater?
Yes, using a method called phase control. This method is also used in dimmer switches to continuously reduce the brightness of lights.
What is hinhem scr?
its a virus that keeps sending out messages that you have not writtin on yahoo...download AVG and you can get rid of it.
What are the three terminals of a silicon bilateral switch?
Anode, Cathode and Gate. Like in a SCR
What is SCR Give its application?
scr is a silicon control rectifier used to control the rectifing voltage.. its a bidirectional device can use it for both the directions......
Why scr is called as bidirectional an controlled device?
Because it can control input voltage in both halves of cycle.
How do you use scr as a diode?
scr is basically a three terminal device can be used as diode by leaving one terminal
Is SCR the unipolar device?
SCR is bipolar device since current is due to both electrons as well as holes.
An scr is an electronic device that?
That is used as a switching device. They are very common in Inverter circuits and can switch up to 1000's of amps.
Why triac is called as bidirectional controlled device?
The TRIAC is called a bidirectional controlled device because it operates in two quadrants. It will conduct when MT2 is more positive than MT1 while the gate is more positive than MT1, and will also conduct when MT2 is more negative than MT1 while the gate is more negative than MT1.While not exactly the same thing, an SCR can appear to operate like a TRIAC if the SCR is placed at the center of a bridge rectifier. (Its not exactly the same thing because of the forward drop of the bridge diodes and because the gate voltage is different in this mode of operation.)
Is SCR active device?
scr is active component because it's generated energy or amplified energy
What is avalanche break down in scr?
A: As the reverse voltage is applied to the SCR increases at a certain point the device will start to conduct that is defined as the breakdown voltage for that device
Is a SCR a voltage rating device or a current rating device?
Check the databook for the SCR you are using. Without knowing the part number, I can't look it up for you.
Is scr current controlled device?
yes it is current controlled
How is an SCR turned off?
Once an SCR has been turned on by means of a gate pulse, it latches, or remains on. The only way to turn the SCR off is to either remove the anode to cathode voltage, remove the load current (SCR's have a minimum current below which they will not fire), or reverse bias the SCR. If the SCR is used in an AC circuit, turn off is easy. This is because the voltage falls to zero, then reverse biases the SCR every cycle. This naturally turns off the SCR. In fact, you have to re-trigger the gate every cycle to turn it back on. In a DC circuit, the SCR must be reset by some means as mentioned above. Once the SCR fires, there is nothing you can do to the gate to control the device. The gate only turns it on, not off. There is a similar device, called a GTO, or gate-turn-off device, that can be turned off via the gate. Once an SCR is on it will not turn -off unless the minimum holding current is met. that can be accomplished by reversing anode polarity or by decreasing loading to below holding current
What is the basic function of the SCR's gate electrode?
The SCR's gate electrode is used to turn the SCR on, i.e. fire it.
