Electronics Engineering

Depending on how the transistor is biased and various other circuits connected to it, a transistor acts as an amplifier and/or switch.

When acting as an amplifier the circuit containing the transistor can do things like transmit or receive radio signals, perform analog mathematical calculations, generate waveforms, etc.

When acting as a switch the circuit containing the transistor can do things like turn on/off a light, turn on/off a motor, perform digital logic or mathematical operations, fetch and decode computer instructions, etc.

Exactly what a transistor can do is really only limited by the system requirements and the designer's imagination as to how to meet those requirements.

There are several different types of transistors: bipolar junction transistors (BJTs), field effect transistors (FETs), unijunction transistors (UJTs), programmable unijunction transistors (PUJTs), spacitors, surface barrier transistors (SBTs), tetrode transistors (TTs), point contact transistors (PCTs), etc.

Voltage (of a circuit) as defined in the NEC: n. The greatest root-mean-square(rms) (effective) difference of potential between any two conductors of the circuit concerned. Voltage as defined by Webster's: n. Electromotive force or potential difference, usually expressed in volts.

A short circuit is a low resistance connection where one is unexpected. It causes a diversion of current from the intended load, and, since it is usually a higher than expected current, it often causes the protective device (fuse, circuit breaker, or relay control logic) to trip.

"k" means thousand

"m" means million

A wire with some resistance and a voltage applied to it

The amount of current I passing this wire is V/R

The time base of an oscilloscope is used to increase or decrease the time per division value on the Y-axis ranging from few tens of seconds to micro seconds to nanoseconds used for microwave signals.If you increase the time base of an oscilloscope lesser and lesser part of the signal will be present in one division of the Y-axis. Setting the time base to a proper value will enable you to see high frequency signals clearly otherwise each cycle of the signal would be indistinguishable from the other huehue

To calculate the current through an LED, use the following formula

Current = (Source_voltage - Led_voltage_drop)/Resistance

Now if you didn't use a resistor, the you only have the resistance in the wire, which is very small (eg .001 ohm).

So if you have for instance a 9V battery, and a 2.1 volt drop across the LED, the resultant current would be so high, it would destroy the LED.

We put a resistor in to lower the current to an acceptable range (often 20-30ma)

Unless it's an old vw bug, cars usually run on a 12 volt dc system nowadays.

Motorcycles often run on a 6 volt dc system.

Different systems require different charging voltages so you won't ever be able to charge a 12 volt car battery from a 6 volt motorcycle battery charger as the output voltage would be way too low.

However, if you can set the battery charger's output to give either a 6 or a 12 volt output, then you must always remember to set it to 12 volts if you want to use it to charge a 12 volt car battery.

Yes, you can. Here's why.

If a supply's output is rated at 12 volts DC (12 VDC) and 500 milliamperes (500mA), it can deliver a maximum of 500mA at the 12 volt rating. You want to use a 12VDC supply that is rated at 1A (1000mA). That means that the supply is capable of delivering up to 1A at 12VDC. Now the crux of the matter.

Your device, that's the load on the supply, needs 12VDC to operate. Your replacement supply is rated at 12VDC. No problem. Your supply delivered a max of 500mA. That does NOT mean that your load, that thing you're powering up, actually uses all 500mA. Your load knows how much current it needs to draw. Your supply has to be rated for more than that. Your supply was rated at 500mA. It worked well. The supply you wish to use will deliver a max of 1A (1000mA). It will easily supply the current your load will use. Oh, and the polarity of the new supply must be the same as that of the old one. That's pretty obvious. Always be safe and consult an electronics specialist for electrical questions. There are a number of savvy folks working at consumer electrical outlets who can get you up to speed.

Gray code is useful because only one bit changes at a time. When used as encoders for a position sensor, for instance, if the sensor were right at the edge of a change boundary, there is uncertainty as to position. Binary code would introduce variable uncertainty in position, because more than one bit can change at a time, but gray code would reduce that uncertainty to being only one bit position in size.

Resistance, and therefore resistors, are a part of any electrical conductor. They were not created but rather, discovered and put to use in electrical and electronic circuits.

DWDM (Dense Wavelength Division Multiplexing)

If you really work hard every course has a good scope.

As we bring P type and N type semiconductors fused together, then rich holes in P type would get neutralized with some rich electrons in N type. Hence at the juntion region, there will not be charge carriers ie holes and electrons. So it is known as Depletion Region. Depletion means emptying something. In case of ordinary diode this depletion region would be wider where as in case of Zener Diode the depletion region would be narrower. This is because the semiconductors are heavily doped. Hence potential barrier would be easily built up even with a thin region where holes and electrons get combined for neutrelization.

I assume a series of amplifiers with one F/B The F/B is the portion of voltage/current F/B from input to output no matter how many amplifiers are in series within the loop or what the gain of each one is.

A battery is usually thought of as a source, not a load. If you are charging a battery, then it will be resistive, especially if you are attempting to charge it like you should, with a DC power supply (not AC).

A digital multimeter is a instrument which is used to measure voltage, current, resistance also it can measures frequency and periodic waveforms. It manly used as test equipement, for example if you had created a circuit you can use it to see if there a fault so then it can be corrected.

Digital meters tend to be more accurate, as they have a very high input impedance, so have less affect on the circuit being measured.

Having a digital output gets round the parallax problem reading a needle.

Having no moving parts, makes them more rugged and less likely to get out of calibration.

The only downside of a digital meter is its harder to see a fluctuating measurement. Watching a needle is better in this case, than watch numbers change.

........V

I = ------

........R

I = Ohm's Law

V = Voltage

R = Resistance

(Ignore the dots they stop V and R from moving to the left!)

Yes you can. All the 1300 mA rating means is that adaptor can supply devices up to 1300 mA. The old adaptor's limit was 800 mA. The new adapter has 500 mA more in reserve if it is ever needed.

Yes, you can wire a 6 ohm sub with a 4 ohm sub to the same amplifier, but you need to verify that the amplifier can handle the resulting impedance of 2.4 ohms - many cannot, and could be destroyed. Also, realize that the power in the 4 ohm sub will be greater than the power in the 6 ohm sub.

Biasing the transistor so that it remains into the linear range is one way the other way is to couple one stage to another via a capacitor to remove extra biasing DC voltage therefore remaining into the linear range