Voltage Doubler Circuit

Voltage Doubler Circuit

Summary

The circuit describes below is used to double the input DC power given.This circuit is useful when you require higher voltage level from a single lower voltage power supply.

Description

This circuit is based on 555 timer wired in astable mode means it will produce a square wave at a frequency of 2KHz approx.with the help of components R1,R2 and C1.When input power is supplied to the circuit we get the output on pin 3 of IC1.

Here C3 and D2 are connected in forward bias and used to amplify the signals and diode D1 is used to protect the C3 from complete discharge. The following capacitor C4 is therefore charge with a combined voltage from C3 and power supply. Therefore in this circuit components C3,C4,D1,D2 are used to boast the input power given.

In this circuit we can change the value of capacitor C3,C4 as we increase the value charging and discharging time also increases and we have to wait for output means output will increase slowly and if we reduce the value reverse action will take place but keep in mind do not reduce the value of C3 so much that it may become hot. In this if you do not use C4 than you will get approx. 2 Volts less in output.  

Note we can supply the input voltage from 3V- 12V not more this if we exceed the limit it will destroy the NE555 IC.We can also use 1N4148 diode in place of 1N4007 but output voltage will decrease because  breakdown voltage point of both diode differ.

Components used

IC
IC1(NE555)	1
Resistor
R1(10K)	1
R2(33K)	1
Capacitor
C1,C2(.1uF)	2
C3(47uF)	1
C4,C5(470uF)	2
Miscellaneous
D1,D2(1N4007)	2
Battery	1

BEGINNERS GUIDE

Want to make your 1st project lets start.

BASIC TOOLS

Before starting your new project you will require a few basic tools to complete your first project. The most important tool you will require is soldering iron and some solder wire. You will also need some more tools like wire-cutters, wire-strippers and a pair of small pliers. Other items are also useful although not essential.
ESSENTIAL TOOLS REQUIRED ARE AS FOLLOWS-
Soldering iron – A soldering iron is a hand tool used for soldering the components. It supplies heat to melt the solder so that it can flow into the joint between two workpieces. You can use power rating of between 15-25 watts which is suitable for most work. A higher wattage does not mean that the iron runs hotter - it simply means that there is more power in reserve for coping with larger joints.  
Bit size – WE should pick a tip that's slightly smaller than the pad you're soldering. As bit size vary in shape size and according to the types of work. Pyramid tips with a triangular flat face and chisel tips with a wide flat face are useful for soldering sheet metal, Fine conical or tapered chisel tips are typically used for electronics work. If you are a beginner we suggest you to use Spade shape bit.
Solder wire –  It is a fusible metal alloy used to join metal work pieces together and having a melting point below that of the work piece. Solder is a metal or metallic alloy. The most common used alloy is some combination of tin and lead. The most common alloys used for electronics work are 60/40.Melting points of some common solder alloys.

Tin/Lead   Melting Point
40/60 230 degrees C          
50/50 214 degrees C
60/40 190 degrees C
63/37 183 degrees C
95/5               224 degrees C

If you need to solder very fine electrical circuits, like jewelry or joints that are hidden in very tight places you should use the solder wire in the range from .01-inch to .05-inch, and if you want to solder household electrical work you should go for .5-inch.

For beginner we will suggest they should go for 20 -22 SWG (standard wire gauge) of thickness.

Flux – Flux act as a cleaning, flowing, purifying agent. As a cleaning agent, fluxes facilitate soldering, brazing,
and welding by removing oxidation from metal to be joined. Commonly used fluxes are: ammonium chloride for soldering tin, hydrochloric acid and zinc chloride for iron and braze for welding ferrous metal.

Cutting pliers – Side cutters have blades placed at one side so that they  can be used to easily and neatly crop the ends of component leads after the components have been soldered to a piece of  Printed Circuit Board (PCB).

Long nose pliers – A pair of long nose pliers is used for holding or bending the leads of components and holding nuts while you tighten bolts.
Wire strippers – For soldering we will most likely be use thin wire like single core or multi strain wire when connecting off-board components to the strip board or PCB, or when constructing a prototype circuit on breadboard. Wire strippers like the one shown can be easily adjusted to make stripping the insulation off these types of wire simple.
Track cutter – A 3mm drill bit can be used instead, in fact the tool is usually just a 3mm drill bit with a proper handle fitted.
Tweezers – Tweezer is a very useful tool for holding screws and  aligning them into their threaded holes and for holding thin wires while soldering or picking up and holding small components.
Magnifying glass – Magnifiers are used to see the small markings on components and also for examining circuit board traces and solder connections. If you can, you should solder under magnification using a magnifying work lamp, but you can start with a hand magnifier.



De-Solder tool – Useful when you need to remove a solder joint for whatever reason you will require the following tools-
De-solder pump – It is a tool for removing solder when de-soldering a joint to correct a mistake or replace a component. It is a spring-loaded suction pump with Teflon nozzle.

De-soldering wick – It is a copper braid woven using fine copper wire and is impregnated with flux. It comes in rolls of one to one-and-a-half meter length. About a cm or so of the wick is placed over the soldered joint to be de-soldered and the hot solder-iron tip is pressed over it. As the solder melts, it gets trapped in to the braid’s mesh.

TEST EQUIPMENT

Multimeter – This is the basic equipment you should have with you because if your circuit does not work you can troubleshoot it with the help of multimeter. Multimeters come in two flavors:
1.Digital
2.Analog - Analog multimeters are old Fashioned — but still useful
Multi meters come with a pair of test leads. Generally Black for the ground connection, Red for the positive connection.
You can use a multi meter to take a variety of electrical measurements. With this one test equipment you can -

• Measure AC voltages
• Measure DC voltages
• Measure resistance
• Measure current going through a circuit
• Measure continuity (whether a circuit is broken or not)
• Test the operation of diodes and transistors  

My recommendation:  Have you own multi meter

Power Supply – Is also very useful for powering circuits that you are testing. One with a variable voltage up to at least 20V is best. The current rating doesn't need to be that high; 1A maximum is fine for most jobs.

MOUNTING OF COMPONENTS

Insert the components – Try to insert components in order of size, smallest first. It can be very difficult to insert small components if larger ones are in the way. If any wire links have to be solder then solder it first. Following order may be follow for soldering the components
1. Jumpers (wire connection)
2. Resistor
3. IC base
4. Capacitor
5. Inductors
6. Transistor
7. LED
8. Triac
9. Voltage regulators
10. Transformer
Make sure – Components such as resistors sit flat on the board, so there is no gap between the component and the board. The only exception is where components may dissipate some heat. Apart from looking neater, it gives the components some protection. However, some components such as transistors should stand slightly proud of the board.
Be systematic – About inserting components, and try to make the board look as neat as possible. A neat looking board is more likely to work first time too. If you are not happy with how a component has gone in, or a joint looks bad, carefully remove it and try again. Solder joints should be shiny, if not you have probably made a 'dry joint' which needs removing and re-making.
Check – You have connected external components the right way round, and to the right points on the board. Components such as LEDs, diodes, transistors etc. are polarity sensitive.

DOUBLE-CHECK THE POLARITY OF THE BATTERY AND ANY POLARISED COMPONENTS (CAPACITORS, TRANSISTORS ETC.) AS A MISTAKE HERE COULD DAMAGE THE CIRCUIT!

Some components require special care when soldering. Many must be placed the correct way round and a few are easily damaged by the heat from soldering. Appropriate warnings are given in the table below, together with other advice which may be useful when soldering.

	Components	Pictures	Reminders and Warnings
1	IC Holders (DIL sockets)	*	Connect the correct way round by making sure the notch is at the correct end.  Do NOT put the ICs (chips) in it while soldering.
2	Resistors	*	No special precautions are needed with resistors.
3	Small value capacitors (usually less than 1µF)	*	These may be connected either way round.  Take care with polystyrene capacitors because they are easily damaged by heat.
4	Electrolytic capacitors (1µF and greater)	*	Connect the correct way round. They will be marked with a + or - near one lead.
5	Diodes	*	Connect the correct way round silver line is for cathode.  Take care with germanium diodes (e.g. OA91) because they are easily damaged by heat.
6	LEDs	*	Connect the correct way round.  The diagram may be labelled a or + for anode and k or - for cathode. The cathode is the short lead and there may be a slight flat on the body of round LEDs.
7	Transistors	*	Connect the correct way round.  Transistors have 3 'legs' (leads) so extra care is needed to ensure the connections are correct.  Easily damaged by heat.
8	Wire Links	* single core wire	Use single core wire on breadboard; this is one solid wire which is plastic-coated.  If there is no danger of touching other parts you can use tinned copper wire, this has no plastic coating and looks just like solder but it is stiffer.
9	Buzzers		Connect the correct way round.
10	Wires Multi Strain	*	You should use stranded wire which is flexible and plastic-coated while soldering wires on PCB  Do not use single core wire because this will break when it is repeatedly flexed.

SOLDERING

So, now you've got some tools, and you're ready to start. This will give you something to practice soldering with. When you've got all now it's time to get started.

HOW TO SOLDER

Plug in the iron – And wait about 5 minutes for it to heat up. Place it on something that won't burn, and make sure the 'bit' isn't touching anything, including the mains lead. Ideally use a stand.
Tin the bit – Melt a small amount of solder onto the tip and wipe the hot iron on a wet sponge use cellulose sponge, not a synthetic one that will melt and stick to the iron. Make sure the sponge is damp - using it dry will only mess up the sponge and won't clean the tip. This will put a layer of solder on the tip.
Bend the leads – Bend the component with pliers to fit the board. Insert it into the board from the side without metal strips and bend the leads outwards on the other side to hold it in.
Benefits of Pre-Bending

• Pre-bending is a technique that allows components to be easily inserted into a PCB.
• Pre-bending also allows components to lay more flush with the board.

Bending components to the correct bend radius takes practice, but mastering the technique will reap rewarding benefits.


Place the tip – Of the iron on the lead where it comes through the board on the side with the metal strips. Make sure it touches the lead and the board.

Wait a second – Or two for the board and the lead to heat up. Don't leave it too long; otherwise you will damage the component. This is particularly important with semiconductors - transistors, diodes, I.C.'s etc.
Feed the solder – Into the joint until it forms a ring around the leads of the component. It should stick properly to both the lead and the copper strip on the board. DO NOT carry the solder to joint on the tip of the iron, this almost invariably produces a bad joint.


Remove the iron – And allow the joint to cool naturally. DO NOT cool it by blowing on it. The joint should look volcano shaped. If it is not shiny, or has formed into a blob then you have made a 'dry' joint. If the joint is not complete re-apply the iron and add a bit more solder.


If you need to remove the solder – Use a de-soldering tool or solder braid, or melt the solder and tap the edge of the board on the worktop to knock it off. Try again - practice makes perfect!
When the joint is OK – Use side cutters to cut the component lead. Repeat the process for the other leg(s) of the component.
When you've finished – Soldering, clean the tip on the damp sponge and then re-tin it with fresh solder before you unplug the iron. This protects the tin plating on the tip and prevents it.
Rules for good soldering-
Rule #1: A good mechanical connection is necessary before you solder!
Rule #2: Strike while the iron is hot!
Rule #3: Heat the work, not the solder! 
Rule #4: Inspect the connection under magnification! 

COMMON PROBLEMS

Too much solder – Joint will form into a blob, solder may bridge between strips on the board. Remove ALL the solder as described above and try again.
Too little solder – Joint not complete, physically weak, possible not electrically sound either. Re-apply the iron and add a bit more solder.
Solder will not stick – Component lead or board may be greasy or tarnished. Generally you should clean the lead and the board before soldering them.
Now start building our project and make sure you can produce good solder joints, as you will only spend more time later de-soldering bad joints, and may damage the components. When you're happy that you’re soldering is good, it's time to start more projects.

TESTING & TROUBLESHOOTING

Before you apply power, read the instructions carefully to check you haven't missed anything. Check again that you have polarity sensitive components that you have put them in right way around, and that all components are in the correct places. Check the underside of the board carefully for short circuits between tracks - a common reason for circuits failing to work.
When you are sure everything is correct, apply power and see if the circuit behaves as expected, again following the instructions given in manual.
If it works, WELL DONE! You have your first working circuit - be proud of it!
If it doesn't quite work as expected, or doesn't work at all, don't despair. The chances are the fault is quite simple. However, disconnect the power before reading on.
Check the basic's first – Is power supply is coming ? Are you sure the 'On' switch really is on? (Don't laugh, it is the common mistake) If the project has other switches and controls check these are set correctly.
Next – Check again all the components are in the correct place - refer to the diagram in the instructions. Look again at the underside of the board - are there any short circuits? These can be caused by almost invisible 'whiskers' of solder, so check for these with a magnifying glass in good light.
Pull the components gently – To see if they are all fixed into the board properly. Check the soldered joints - poor soldering is the most common cause of circuits failing to work. The joints should by shiny, and those on the circuit board should be volcano shaped with the component wire end sticking out of the top. If any look suspect then redo them. Remove the solder with a solder sucker or braid and try again.
Check – For solder splashes shorting across adjacent tracks on the circuit board, especially where connections are very close such as on integrated circuits ('chips'). Solder splashes are most likely on pcb. You can check for shorts using a multimeter set it to continuity range, or low resistance range. Be aware if you do this though, that there will be a resistance between some tracks due to the components. Any resistance below 1 ohm between tracks is likely to be a solder splash. Run the soldering iron between tracks on pcb to remove any solder bridges.
If the circuit – Still fails to work you will need to refer to the circuit diagram and take voltage readings from the circuit to find out what's wrong. You will need a multimeter to do this. Remember that if you find one fault such as a reversed component and correct it, it might have caused damage to other components.
Now you could build more kits to get more confidence.

HOME MADE PCB

HOME MADE PCB

Printed Circuit Board or PCB is generally used to mechanically support and electrically connect the components with help of conductive path ways or traces made on copper clad sheet. In another words PCB is used to create a electrical connection between different components like resistor, capacitor, integrated circuits,IC’s etc.

In general PCB has two sides-

1. Front side – Also known as Components side, which is used for placing variety of electronic components.
2. Back side - Also known as Track side, which is printed with electrically conductive pathways for connecting the components.

For making a PCB following things are require-
1. Copper clad sheet
This is available in different size and dimension. You have to select the size of sheet according to your circuit. Thickness of copper clad sheet also plays an important role, used thickness equal to 1.2 to 1.5mm approx. because it will start bending if you have used sheet of less thickness.
This also has two sides-
a. One which has copper on its side used for making traces or used for soldering the components.
b. And another side has plastic or bakelite used for mounting the components.
Note-Before using the copper clad sheet wash it properly no dirt or water vapor should be present on it or you can also use pencil eraser to clean the surface of PCB.
2. Ferric chloride solution
Also known as FeCl3 used to remove the unwanted copper from the copper clad sheet or used for making conducting path. Time of etching depends on the concentration of FeCl3 mixed with water. Basic ratio may be 50gms Ferric chloride in 100ml of water.
Please take care-FeCl3 is a toxic solution and can cause skin burn and irritation so be careful, use hand gloves during etching, if contacts happen with FeCl3 immediately wash with water.
Kindly do not through the remaining FeCl3(after etching) into the drain because it contain copper ions which are dangerous, neutralize it with the help of sodium Carbonate or sodium hydroxide  and check the ph value it should be approx7-8 before disposing it or you can add more water to dilute it.
3.  PCB drilling machine and drill bit
Drill machine are used to make hole in PCB for mounting the components. While drilling the PCB you should be very careful about the size of hole because different components leads have different size. Kindly measure the leads before drilling. In general use following sizes for making hole for different components.
a.1mm-for IC Base
b.1.2mm-for Resistor,Capacitor,Transistor,LED
c.1.5mm-for Diodes,Preset
d.5mm-for Nuts,Screws
e.8mm-for Switch

4.  Permanent Marker, sticker paper, Iron, Whitepaper, Cello tap, Tray for etching, Scrubber for cleaning PCB.

Steps for making PCB are as follows-

1.  First draw your required circuit diagram on paper.

2.  Now take sticker paper remove the front part and put above you circuit and only draw conducting path and drills points. Be careful do not overlap the conducting traces. Like as shown in fig. below.



3. Now darken the layout with the help of permanent marker draw carefully there should be no overlapping or shorting of tracks or components. As neatness of PCB lies in pattern drawing. You can also take the print out of the same on sticker paper.

4. Now carefully cut the required copper clad sheet and wash it properly. Now place the sticker paper on copper side of copper clad sheet.

5. Carefully cover the sticker paper on copper clap sheet with the help of tap. Be careful there should be no air bubble inside.

6. Now take a iron(used for ironing clothes) set the temperature to approx. in middle and iron your sheet on the sticker paper side by applying pressure for approx.10 minutes.

7. After that put your PCB underweight if you do not do this then there is a chance that your PCB may bend. Keep it until it become cool.

8. Now remove the paper very slowly and see you have transformed the print on copper clad sheet.

9. Now carefully examine the sheet for shorting, missing of tracks with help of circuit diagram.

10. Now again darken the traces with the help of permanent marker.

11. Fill the extra space present on Copper Clad Sheet with marker it will save your etching time. Like shown in Fig.



12. Now put your PCB in feCl3 solution for etching keep it for 15 minutes then see if it is properly etch or not.

13. After this wash it properly with the help of Scrubber. Your PCB may look like this.




14. You can tin your tracks with the help of solder wire it will prevent oxidation on pcb from environment hence increases the life of your pcb.

Your PCB is ready for use

UNDERSTANDING NAND GATE (CD4011)

UNDERSTANDING NAND GATE (CD4011)

INTRODUCTION
CD4011 is the most commonly used Complementary Metal Oxide Semiconductor (CMOS) chip.  It comes in a 14 pin Dual Inline Package (DIP). It has small notch on one side which identifies as pin 1.It consists of 4 independent NAND gate in a single chip. Each gate has 2 inputs and 1 output. Working voltage range of IC is from 5V to 16V. It can deliver approx.10mA at 12V but this can be reduce as power supply voltage reduces.
IC consist of 14 pin in this pin 7 and 14 is connected to battery or DC power supply. Negative is connected to pin 7 and pin 14 is connected to power supply. As we know it has four gates we call it NI1, NI2, NI3, NI4. In first gate NI1 pin 1 and 2 are for inputs and pin 3 is for output. As you can see in the circuit below.
As we can see in the truth table it will provide the output equal to one when any one of the input is low. In another words we will receive the high output when any of the signals goes low. And if both the inputs are high we will receive the low output.

Working of NAND Gate
To understand the working let us consider a circuit diagram of gates
In the diagram above consider that we have supply logic high to pin1 and 2 of NI1as a result we will receive logic 0 in output pin 3 as you can see in truth table. Therefore we will  receive logic 1 at output of pin 4 because 0 is passed to NI2 gate from pin3 so whatever may be the input from pin 6 we will receive high at pin 4. This means that we will receive 12 V at pin 4. As a result current start following in capacitor and capacitor starts to charging as a result we will receive high on pin 8 and 9 and logic 0 at pin 10 because of which it is connected to pin 6.As a result we will not require pin 5 output is maintained by gate NI2 and NI3.
But as capacitor charges voltage on resistor drops to half the power supply NI3 detects a low on in its input as a result logic 0 appear on pin 10. Now logic 1 is on pin 5 because no logic is present on pin 1 and 2 as pin 6 is also high we will receive 0 at pin 4 as result capacitor start discharging on pin 8 and 9 and circuit again start working.
From above we can see that for a certain period of time circuit will work and then goes off. Time period of operation can be determine by-T=.7*R*C.

Application Of NAND Gate
Logic gate have many application like in computer circuits.

1. The circuit below show how a NAND gate is used to activate a light bulb if any of the door is left open. A door which is properly shut will open a normally closed pushbutton switch and apply a logic “1”to the gate input as a result bulb will not glow and when any of the door is not properly shut applies a logic “0” to the gate and a result bulb will glow and we came to know that any of the door is not properly shut.

2. NAND  Gate as INVETER-

   IN	OUT
   L	H
   H	L

   
   
   In the circuit diagram above when we will give input equal to 1 we will receive output as 0 and when 0 is given we will receive 1 as output.
   
   3. NAND Gate as Switch
   The circuit below will give a high output when we touch the both wire together. Working of the circuit is very simple as pin 2 is connected to power supply it is always maintained a high at its input. When wires are not touch circuit is open and we receive a high at pin 1 and when wires are touch we will receive 0 at pin 1 and we will get the output as a result LED will glow.