At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non...
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non...
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non...
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non...
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non...
Circuit Analysis - Operational Amplifier Tutorial - Effects of Finite Gain - A video Tutorial of How a Basic Op-Amp works and How to calculate its effective gain to make u understand more easy.And if you find any difficulties just say it.Or if you want to know anyother related videos just ask it via comments!
Do you have any query or doubts,want to know that PLEASE ask it or leave your ideas at comment..
When removed from the etching solution, the PCB is washed and a PCB eraser is used to remove any film from the tracks. This must be done carefully because the film will prevent good soldering of the components to the PCB. The tracks can be checked using a magnifying glass. If there are gaps in the tracks, sometimes they can be repaired using wire but usually a new PCB has to be etched.
The last stage is drilling the holes for the components. A small PCB drill is used for this purpose.
Again care is needed as a good PCB can be ruined by careless drilling.
This completed Printed Circuit Board (PCB) has all its components soldered in position. It has been manufactured through the processes described in the information sheets.
PCBs manufactured in industry are designed on a computer and then manufactured on an production line controlled by computers. Usually there is very little human contact.
QUESTIONS: 1. Describe the stages involved in the manufacture of PCBs - using simple, labelled diagrams. 2. What safety precautions should you take when using ‘developer’ and the ‘etching solution’ ? 3. Complete the notes on the PCB sequence drawing OR place in order the cards representing each stage of manufacturing a PCB. Then place the correct text box underneath each picture. 4. List the advantages of using electronics / PCB simulation software compared to using a breadboard to test a circuit design. 5. What quality checks should be carried out when manufacturing a printed circuit board (PCB). 6. What material is a PCB?
Do you have any query or doubts,want to know that PLEASE ask it or leave your ideas at comment..or Just mail me:
PHOTO-RESIST BOARD is a piece of glass reinforce plastic. One of the sides is copper clad and this copper has a photosensitive coating. When the plastic film is peeled back this sensitive coating is revealed.
After processing this will be the PCB.
The PCB mask (now on a transparency) is placed underneath the photo-resist board, touching the sensitive surface. Remember the plastic film must be removed. PCB mask and board are then transferred to the UV light Box.
You must be careful to ensure that the PCB mask is the right way up, otherwise when the circuit is etched you will discover that the tracks are also the wrong way round.
The lid is shut and the box switched on. The photo-resist board, with PCB mask are left underneath the lid for 2 ½ minutes. The photo-resist board is then placed in a tank filled with developer (using plastic tongs)
It is important that the board is only left in the developer for approximately ten seconds.
When the board is taken out of the developer it must be washed in clean water before transferring to the etching tank. Always use plastic tongs.
The etchant is held in a ‘bubble etch tank’ and is heated. This solution slowly etches away the unwanted copper, leaving the tracks only. At this stage it is important to keep checking that the PCB is completed (time - 15 to 45 minutes). If it is left in the tank too long the copper tracks will also be removed or damaged.
Once a circuit has been designed and simulated / tested in Crocodile Technology and any necessary alterations made, the completed circuit is ready for export to ‘real PCB’®. Both Crocodile Technology and Real PCB software must be running at the same time for this to be possible.
(Please note: the uptodated version of Crocodile Technology is called Yenka Electronics. This allows the design and conversion of circuits to PCB, in an integrated environment)
Circuit Wizard is a very good alternative piece of software that allows the design of circuits and conversion to PCB.
The conversion to PCB layout can be achieved through a menu in Crocodile Technology. Real PCB converts the circuit diagram effortlessly to PCB layout and usually with 100% accuracy.
Real PCB can also be used to construct a circuit as a PCB layout, from scratch, by selecting components from a series of menus and drawing the tracks connecting them. It can be used by both beginners and experts to produce accurate PCBs. Quality checks can be carried out automatically and the software will also produce a bill for the components used on any PCB.
The ‘Pour Copper’ menu changes the final PCB by only removing enough copper so that the tracks can be seen. This means that only the necessary copper is removed to ensure the final circuit works. This extends the life of etchant used in the etchant tank.
Two more ways of presenting the PCB are shown below. The 'artwork' layout is the most likely to be printed out on a transparency, ready for conversion to PCB. The real life layout style shows the PCB with its components. This is useful when arranging the components on the PCB, as the position of each can be check against a real life printed.
When the PCB layout is finished it is printed on a transparency and becomes known as a PCB mask. The PCB mask is transferred to the UV box, which is the next stage in the manufacture of a printed circuit board.
Advantages of using circuit and PCB software: 1. Circuits can be simulated on screen without the need to build a circuit on a breadboard with real components. 2. Errors can be corrected and alterations made to the circuit by simply replacing components from menus. 3. No soldering is needed, simply move components with a mouse. 4. Using simulation software is safer than soldering with hot soldering irons and avoids dangerous fumes being produced whilst soldering.
5. Once a PCB has been designed it can be printed onto transparencies repeatedly, all to the same high quality. 6. PCB layout software is more accurate than drawing a circuit by hand.
Friends do you know how PCB boards are made,and what it had in this??Just go through this post.
Electronic circuits in schools and industry are normally manufactured through the use of PCBs (Printed Circuit Boards). The boards are made from glass reinforced plastic with copper tracks in the place of wires. Components are fixed in position by drilling holes through the board, locating the components and then soldering them in place. The copper tracks link the components together forming a circuit. The animation shows the components arranged on the 'component side' of the PCB and as it rotates, the copper tracks are also shown.
The two diagrams below show the track side of a PCB (normally the underneath side) and the component side (normally the top side) of the same circuit. The relay and integrated circuit are ready to be placed in position and soldered.
A circuit such as the one shown opposite can be drawn using software such as ‘Crocodile Technology®’ (now known as Yenka Electronics). This allows individual components such as resistors, integrated circuits and capacitors to be dragged onto the screen and connected together, forming a complete circuit. The finished circuit can then be simulated on screen. If the circuit is not correct it can be altered until it works in the desired way.
This allows you to test the circuit on the computer and correct any mistakes or make improvements. This saves time as there is no need to build the circuit with real components.
Circuits can also be built on a breadboard using real components. This is a time consuming method and often mistakes occur as many components are small and it is easy to connect components incorrectly, causing a circuit to fail. Also, breadboards are prone to damage as the small connections on the boards are quite delicate.
Using simulation software such as Crocodile Technology® is recommended as it is a much more reliable and accurate method of testing a circuit.
Opposite is a simple temperature sensor. It operates in exactly the same way as a light/dark sensor except that it has a component called a thermistor rather than a LDR (Light Dependent Resistor). The thermistor's resistance value changes when the temperature rises or falls. This ‘triggers’ the relay.The preset resistor allows the person using the circuit to alter its sensitivity to changes in temperature..
When are temperature sensors used?
Do you have any query or doubts,want to know that PLEASE ask it or leave your ideas at comment..or Just mail me:
Opposite is a simple light/ dark sensor. This can be connected as an input or switch to another circuit. The sensors has three green wires (1, 2 and 3). Wire 2 should always be connected to one of the inputs. If wire 1 is also connected then the sensor acts as a dark sensor. If wires 2 and 3 are connected to the inputs then sensor operates as a light sensor.The preset resistor allows the person using the circuit to alter its sensitivity to light/dark.
CONSTRUCTING A CIRCUIT USING SIMULATION SOFTWARE
All circuits are drawn on software such as Crocodile Clips. Using this software the individual components can be joined together on the screen. Once the circuit is drawn its operation can be simulated to see if it works. If it fails it can be corrected on the computer screen and tested again.
Using software to test circuit designs saves time as there is no need to physically solder together components. It also saves money as components and materials are not wasted on failed circuits
The circuit is then made into a PCB (Printed Circuit Board). Components are added and soldered in position (See PCB Section of this website). Two views of the same circuit are shown below. How do they differ?
3. Complete the table below by writing some details about the components used in the light/dark sensor circuit.
Do you have any query or doubts,want to know that PLEASE ask it or leave your ideas at comment..or Just mail me:
