Generally SCR is used at high power applications, in order to withstand the temperature dissipated in the SCR, THERMAL STABILITY is very high enough. It means that thermal stability of silicon is very high compared to germanium that's why germanium is not preferred. But that does not mean it is not possible, in fact before silicon became common in the 1960s devices equivalent to the SCR were built using germanium!
Because it is controlled by the gate current
The symbol 'A' indicates that this device is made from germanium . as you may know germanium has less cut in voltage so this device is used for low power signal or for signal processing. also the leakage current or reverse saturation current of germanium is greater than silicon.
silicon controlled rectifier is a 3 terminal 4 layer device which has 2 consecutive P N junctions here the three terminals called anode, cathode and gate gate controls the conduction of the scr but diode just conducts in forward bias and blocks in reverse bias
An SCR (Silicon Controlled Rectifier) is primarily considered a digital device because it operates by switching between on and off states in response to control signals. While it can interface with analog signals, it functions in a binary manner, controlling the flow of current based on gate voltage inputs. Therefore, it is best classified as a digital component used in power control applications.
A Rectifier converts Alternating current into Direct current
A germanium controlled rectifier (GCR) is a semiconductor device that functions as a switch and is used to control the flow of electrical current. It is made from germanium, a material that allows for lower forward voltage drops compared to silicon devices. GCRs can be turned on by applying a gate current, allowing them to conduct in one direction, while they can be turned off by reducing the current below a certain threshold. Historically, they were widely used in power control applications, but have largely been replaced by silicon-controlled rectifiers (SCRs) due to their superior performance in modern electronic systems.
scr is a silicon control rectifier used to control the rectifing voltage.. its a bidirectional device can use it for both the directions......
SILICON CONTROLLED RECTIFIER APPLICATIONS i) Speed control for motors ii) Temperature control for electric hot plate iii) Dimmer switch for domestic lighting iv) Dimmer control for stage lighting.
Because it is controlled by the gate current
Four reasons. First, it is a LOT cheaper and easier to get silicon. Germanium is a trace element in rocks. You need to mine and process lots of rock to get any germanium. Silicon is also known as sand--very easy to find. Second, germanium is heat sensitive. It's harder to solder a germanium device in than a silicon one because the heat can mess up the germanium. Germanium devices pretty much have to be soldered in by hand because you have to heat sink them, whereas silicon devices can be soldered in a soldering machine. Third, germanium's hazardous and silicon is generally not. People eat off glass plates, which are made from silicon. They do NOT eat from germanium plates, if they could even afford them. And fourth, germanium has a variable voltage drop--the higher the voltage, the greater the drop. If you pump 5000 volts into a silicon diode, you're going to get 4999.3v out the other side.
An SCR, a silicon-controlled rectifier, is a four-layer solid state current controlling device. When it turns on it acts like an electronic switch and rectifier.
The symbol 'A' indicates that this device is made from germanium . as you may know germanium has less cut in voltage so this device is used for low power signal or for signal processing. also the leakage current or reverse saturation current of germanium is greater than silicon.
silicon controlled rectifier is a 3 terminal 4 layer device which has 2 consecutive P N junctions here the three terminals called anode, cathode and gate gate controls the conduction of the scr but diode just conducts in forward bias and blocks in reverse bias
A silicon-controlled rectifier is a semiconductor device that is used as a switch in an electrical circuit. It's a solid state direct current (DC) electronic switch. There is a ton of information including a detailed description of the SCR and a list of applications at the Wikipedia article. A link is posted below.
Germanium is less commonly used in electronic devices than silicon due to its higher cost and lower abundance. Silicon is also more stable at higher temperatures, making it more reliable for a wider range of applications. Additionally, silicon has better electrical properties and can form a native oxide layer which helps with device performance.
Silicon transistors are preferred to germanium transistors because they exhibit higher thermal stability and are less prone to temperature variations. Silicon transistors also have a higher maximum operating temperature, improved frequency response, and are more reliable in terms of long-term performance. Additionally, silicon is more abundant and easier to work with in manufacturing processes compared to germanium.
A rectifier is an electronic device that changes an AC voltage to a DC voltage.