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What are modes of biasing a transistor?
Transistor works as amplifier,oscillators,switch only when it is biased properly.biasing can be defined as how much amount of voltage that has to be supplied to each junction of the transistor in order to make it work as any one of the above given types.biasing voltage can be decided by seeing the V to I graph of a transistor
May power amplifier a voltage amplifier?
A power amplifier may also boost voltage; in audio equipment, power amplifiers often have a dial on the front that is used to control the input voltage gain. A simple power amplifier is composed of a single transistor; this type of configuration cannot provide voltage amplification as well. A voltage amplifier stage is needed. So the above example of an audio power amplifier is actually a voltage amplifier stage, followed by one or more power amplifier stages.
Explain clipper in electronic devices circuit?
A clipper circuit will not let a voltage rise above a certain value, perhaps set with a zener diode. A sine wave that is clipped will have a flat top as seen on an oscilloscope. Older transistor audio amplifiers clipped music waveforms giving an unpleasant distorted sound due to the output being clipped at the power supply rail, which was a fairly low voltage before high-voltage transistors were developed.
Transistor work on ac or DC?
Transistors are typically operated in one of two (well, four) regions: saturation/cutoff or linear (forward or reverse). When used as amplifiers, transistors are operated in the linear region. If you look at a transistor's V-I (voltage - current) characteristic, you'll see the linear region is somewhere "in the middle", where there is sufficient voltage applied (so current flows), but not to much (so the transistor is not saturated). To get transistors to operate in this middle region, DC circuits are used to bias the transistor to the center of the linear region. So the transistor is working on both AC (the signal applied to the input that is amplified at the output) and DC (the biasing network to allow the transistor to operate as a linear amplifier). When used in saturation/cutoff, the transistor is being used as a switch (on/off). this is common in logic devices (gates, arrays, CPUs, etc.). The input to these devices is typically an irregular AC wave (a square wave of information). A power source is needed that is DC, however, to provide the power to drive the output to one state or the other. So proper transistor operation requires both AC (as the signal) and DC (as the biasing network, or power source).
How do you make a light go on when voltage is low and off when voltage is high?
You can use a transistor in conjuction with other circuit components. Connect the signal you are monitoring to the gate of an n-channel mosfet, put the light in series with the drain and connect it to positive voltage, connect the source through a resistance to ground. Disclaimer: The above requires you to have a DC source to power the transistor from drain to source. Also, this assumes you are monitoring a DC voltage. If you are sensing AC, you'll need to convert to DC first using a rectifier circuit. Finally, this will not sense "just a little" voltage, since it will take some to turn on the transistor. If you need it to work through full range 0 - whatever max voltage is, you'll need to use a JFET or a more elaborate biasing circuit.
What TTL Logic Voltage Level?
Historically, transistor-transistor logic (TTL) voltage levels have been 5.0 volts, with a high being any voltage above about 3.5 volts and a low being any voltage below about 1.5 volts, with lots of variations on the high/low cutoffs from part to part. Since about 2001, however, most processors have been using low-voltage TTL (LVTTL), which has a nominal voltage of 3.3 volts (approx >2.2 volts for high and approx < 1.2 volts for low). Hence, many parts advertised as "TTL" today actually work at 3.3 volts rather than 5.0 volts.
What are the operating regions of transistors?
operating region of the transistor is the area of the voltage and an electronic configuration in which a transistor can work with its full efficiency. In that operating region transistor can be used easily what above said by harsh is correct...the following may help u further... Based on application the transistor is decided where to lie. for example transistors are made to lie in active region to make it as amplifier. when transistors are used as switch it is made to lie in saturation region(when switch is made as ON) and cut-off region(when switch is made as OFF).....
What economical device - varistor - transistor etc can you use to supply power to a relay until the voltage drops to 10.5 volts?
A zener diode, a transistor, a rectifier diode, and a few resistors. A 10.5V zener diode will conduct until the voltage across it drops to below 10.5. If the relay is small enough, a zener diode is all you need. However, more than likely the current draw of the coil would burn the zener out. Use the zener to drive a transistor, and use the transistor to trigger the relay. V+ | |_______________________ | | _|_| _____|___ |/ \ 10.5V | | /___\ | 3 Relay | __|__ 3 Coil | / \ 3 0---------- /___\ 3 | | | 3 \ \ 4.7K | | / 2.2K / |____ ___| \ \ | / / | | | B | / C | |________|/ | |\ 2N2222 | | \ | | E |______________________| | _|_ \\\ When the voltage is above 10.5V the zener will conduct ant turn on the transistor. The transistor will power the relay. When the voltage drops below 10.5V the zener will stop conducting, shutting off the relay. The rectifier diode absorbs transients caused by the field breakdown in the coil, protecting the transistor. Just a plain resistor will do it or you may follows suggestion and use a computer to do that. The last time i used those ancient devices i find out they operate as a current device like minimum pull in current source. So a passive resistor in series will insure the minimum pull in source however it could be higher then the 10.5 v you need.The above designi just plain silly.
How does capacitor discharge while ac supply is on?
For part of the AC voltage wave, the capacitor will be above the source voltage, and will discharge until the AC voltage wave increases above the capacitor's stored voltage.
What is lower threshold voltage?
the voltage above which any device starts conducting
What is baised?
Transistor is an active device. Active devices (unlike the passive devices such as resistors and capacitors) you have to bias them so that they can function properly. A resistor behaves well no matter what voltage or current you apply to them (it still obeys I=V/R). But a transistor has to be biased at the right voltages in order to operate as what it is supposed to be. For example, in bipolar npn, to have it as signal amplifier (e.g. common emitter), VBE (voltage across Base and Emitter) has to be larger than certain voltage (e.g. 0.7V) and VCE (voltage across collector and emitter) has to be larger than another voltage (e.g. 0.2V). Otherwise, the transistor won't be able to amplify the signals with high gain. In a MOSFET (e.g. NMOS), similarly, we have to bias VGS (gate to source) to be larger than the threshold voltage and VDS (drain to source) to be larger than the saturation voltage. In conclusion, biasing is to use voltage to set the active element at the "right operating region"! The above are just examples. And depends on what you want the transistors to do, you need different "biasing condition". E.g. if you want to make the MOSFET behave like a resistor, you make VDS smaller than the saturation voltage. So, after biasing, how can they be used? Usually, a small voltage (signal) will be coupled to the biased transistors for signal processing.
How much voltage a 0v bulb need to glow?
Some small voltage above 0.
