How to Fix Virtual Router Plus Could not be Started Error

There can be different reasons for the Virtual Router Plus Could not be Started Error. Three methods to troubleshoot this issue are discussed below. Try these methods one at a time in the order 1 to 3, till your problem is solved. Hope these work for you

Method 1

1. Right-click network, click properties, change adapter settings, disable WiFi adapter by right clicking it and selecting disable from the context menu. Not the one created by Virtual router Plus.
2. Once disabled right click on it again to enable it.
3. Now try connecting to internet.

Method 2 

1. Press Windows key + X, select Command prompt (Admin)
2. Then type the following:
   netsh wlan set hostednetwork mode=allow ssid=VirtualRouter key=123456789
3. Enter
4. Then type :
   netsh wlan start hostednetwork
5. Then try connecting to internet.

Method 3

1. Open Network and Sharing Center->Change adapter settings. Alternatively you may right-click network, click properties, change adapter settings
2. Right click the adapter you use to connect to the internet (Ethernet/WiFi/Data Card) and open its properties window.
3. Now go to the sharing tab and enable the 'Allow other network users to connect.....' and select the Home networking connection 'Ethernet/WiFi' as shown in the figure
4. Click OK
5. Now disable and then enable this adapter.
6. Now try connecting to internet.

How to Design an Air Core Inductor

An air core coil inductor is made by winding several turns of enameled wire around a none ferromagnetic material core (like plastic, ceramic, or other non-magnetic forms, as well as only with air inside the windings).

These coils have lower inductance compared to the ferromagnetic core coils. Despite of this characteristic, air core coil inductors are often used at high frequencies because they are free from energy losses called core losses that occur in ferromagnetic cores (which increase with frequency).

In air core coils with winding not rigidly supported on a form (core), a side effect called 'microphony' may occur. 'Microphony' refers to the mechanical vibration of the windings which in-turn causes variation in the coil inductance.

The major advantages of air core coils are:

1. The inductance is independent of the electrical current through the coil since there is no ferromagnetic core to get saturated as the current increases.

2. There is no iron loss as in case of ferromagnetic cores, thus giving a better Q Factor and low distortion with increased frequency.

3. They can be operated at high frequencies (upto 1 Ghz).

The inductance of an air core coil inductor can be calculated using the equation shown in the above figure.

here,

    L = Inductance (in uH)
    a = Diameter of the coil (in Inches)
    b = Length of the coil (in Inches)
    c = Diameter of the winding wire (in Inches)
    n = Total turns of wire

Note: The formula is valid only if the value of b is greater than 0.4a.

How a software interacts with hardware? - Basics of Computer Electronics

In modern computer programming, every software is written using a software programming language. This text program (called high level language) is then converted into runnable (executable - low level language) format by special softwares called compilers(or interpreters). The specialty of this low level language is that it could be understood by a hardware (precisely a microprocessor - a type of electronic component which can perform electronic operation based on software codes). The microprocessor reads the program (low level) and perform the corresponding action.

Now the microprocessor understands a particular code by reading (actually, its sensing electronically) the bits in the particular code. For example if a microprocessor is made in such a way that it will make its 5th pin to +5 voltage level when it reads a bit sequence 0010011, then the processor perform the action whenever it reads a 0010011 in the code. In this way the actions to be performed by a particular microprocessor and the corresponding bit sequence is defined at the time the microprocessor is manufactured. As you know, in a computer system, the microprocessor is the brain, so all the operations are carried out by it.

The computer peripherals (like mouse, keyboard etc) are identified by using configuration files called drivers. These files contain the information that is to be used for interacting with the hardware. The Operating System (windows, linux etc) controls and monitors the peripheral (hardware) control and management.

Best soldering practice tips for the beginners

These are few soldering tips for the beginners in electronics.

1. Keep the soldering surface of the PCB (printed circuit board) clean. If you find that the surface is covered with some corrosive coating, then use a pen-knife and gently remove the contamination over the surface. You should do this carefully so as to avoid damaging the metal lining/plating of the PCB.

2. Never use too much or too little solder-lead for solder joints. Use only the optimum amount of lead so as to keep the component connected firmly to the PCB. Using too much solder may result in a short circuit. Also the circuit will appear ugly in this case. Use of too little solder will result in weak joint or open contacts, which will in turn, affect the working of the circuit.

3. It is not very easy to cut the ‘extra’ legs of the soldered components with a wire-stripper. Moreover it results in imperfect cutting. I recommend using a nail-cutter for this purpose. It will help in doing the cutting job easily and with perfection.

4. Do not use single strand wire for external wiring on PCBs. The reason is that they will break easily. Use suitable multi-strand wire instead (since they have good flexibility, they won’t break so easily). Before soldering, make sure that the insulation is sufficiently removed and the metal strands are properly twisted together at the soldering end of the wire.

5. Use a good quality soldering iron. A good soldering iron will allow the heat to flow to its tip very quickly and effectively thereby giving a better soldering experience. A 25 Watt Soldering iron is the best choice for the electronics beginners. I recommend Soldron iron for Indian hobbyists and Weller SP23LK Marksman for the all International electronics amateurs.  They are two of the best rated soldering irons available in the market. The Soldron iron is available on www.ebay.in or http://www.soldron.com/catalog.php (price around Rs.220-300) and Weller SP23LK Marksman iron on www.amazon.com  (price around 15$ for the iron and 45$ for the Soldering Station).

6. Never do soldering under the fan or near any cooling equipment. This will reduce the tip temperature of the iron and hence the solder-lead will not melt properly, causing a bad soldering experience.

7. Do not keep the soldering iron in contact with the soldering surface for long time. This will damage the electronic component which is being soldered and also it causes oxidants to accumulate on the PCB surface and thereby prevents the solder-lead from attaching to the metal plating of the PCB. As a result the soldering will fail. In this case you have to use a pen-knife to clean the metal surface as explained before.

8. To remove the extra solder attached to the iron-tip, give it a strong shake to the ground (while it is hot). This will cause the molten lead to detach from the iron and fall down. Remember, while doing this, you must be careful about your surroundings since the molten lead will be hot (though for a short time) and might cause damage, if fell on sensitive surfaces.

9. Do not use soldering iron for other purposes like melting plastic or polythene (e.g. for removal of wire insulation), wax, paints etc. It will cause such materials to get attached to the iron-tip and thereby interrupts the heat flow from iron to the solder lead. In this case, you will have to use either a ‘file’ (tool used to sharpen chisels) or a sandpaper to clean the iron-tip.

10. After using for a while, the tip of the soldering iron will wear-off (becomes curvy). This will cause difficulty in soldering. In this case, use a ‘file’ to suitably plain the tip. After long use and repeated ‘filing’, you will find the soldering tip to be very short and thereby causing uneasiness in soldering. In this case, you need to buy a new soldering ‘bit’ (tip) for your iron (provided your soldering iron has an changeable tip). The bit costs only a couple of bucks and is available at almost all electronics stores.

Things you should know before working with Microcontroller Programming

There are a lot of things you need to know before working with your microcontroller project code. I would like to explain some of the important ones. They are:


1.  PROGRAMMING LANGUAGE: A microcontroller program can be written in 3 languages – assembly, c and hex (with the help of a computer). The first two are the practical and most widely used languages. The third method is correct but impractical for large programs.
Each language has its own advantages and disadvantages. In assembly language the program is written using the microcontroller instruction set only. This makes programming in assembly, somewhat complex. The main advantage of using assembly is its fast execution. Because of this reason assembly language is highly preferred in real time systems, for which the time constraint is a serious matter. The ‘c’ language (actually it is micro-c), as its name indicates, is written in the same syntax of the original computer ‘c’ language. The advantage of writing in ‘c’ is the availability of a large number of functions that comes in handy while programming. But the ‘c’ programs are comparatively slower than the assembly programs. In either case you need the simulator software with assembler/compiler. I recommend using the latest version of ‘Keil uVision’ if you are working on 8051 microcontroller, ‘PIC Simulator IDE’ for PIC microcontroller and ‘AVR Studio’ for the AVR microcontroller.


2.  HEX FILE: Though you are initially writing the program code in assembly or ‘c’ language you will have to convert it to hex file before you can put it (program/burn) into a microcontroller flash memory. Usually, the conversion is done by the assembler program associated with the programming (simulator) software. Then the hex file can be loaded into the microcontroller using a suitable microcontroller programmer (hardware).


3.  MICROCONTROLLER PCB CIRCUIT: I recommend that you create a basic microcontroller circuit on a General PCB with the ‘Lock/Eject type’ IC base for the microcontroller. This will help a lot during the microcontroller programming by avoiding the uneasiness and various connection problems while using the breadboard circuit and it also eliminates the need for those costly and bulky development boards.


4.  CHECK YOUR MICROCONTROLLER: Before you test your program code on a microcontroller, you should check whether the microcontroller is functional or not. This can be done by burning a simple program in the microcontroller and checking the result (output). For example, the following test code is written for the said purpose. It is written for 8051 microcontroller in the assembly language:


ORG 00H          ; initialize microcontroller

LOP:

SETB P1.0        ; make p1.0 pin high

MOV R5, #0FH     ; approx. 1s delay

LOP2:

MOV R6, #0FFH

CALL DELAY

DJNZ R5, LOP2

CLR P1.0         ; make p1.0 pin low

MOV R5, #0FH     ; approx. 1s delay

LOP3:

MOV R6, #0FFH

CALL DELAY

DJNZ R5, LOP3

JMP LOP          ; go to ‘lop’ label

;****************************************

;           1s DELAY ROUTINE

;****************************************

DELAY:

DELAYL1: MOV R7, #0FFH

DELAYL2: DJNZ R7, DELAYL2

DJNZ R6, DELAYL1

RET

END


The above code will toggle the 8051 P1.0 pin between high (+5V) and low (0V) with a delay of approximately 1 second. You can see this state switching by means of an LED (with driver-recommended) circuit connected to the P1.0 pin.