SketchingWiki

• Introduction
• Schematic Diagram
  • Schematic Diagram Symbols
  • Schematic Diagram lines
• Solderless Breadboard
  • Why Solderless breadboards ?
  • How it works ?
  • Example to show how to build circuit using breadboard
• Multimeter
• Soldering
• Fritzing
• References

According to (Paul Spinrad,January 2011)The easiest way to translate most schematics into a working circuit through these steps:

• Connect the components together on a solderless breadboard using jumper wires.
• Testing connections and debugging the circuit with a multimeter.
• Committing to soldering on a printed circuit board.

In this article i will try to go through all the steps when converting a schematic diagram into a working printed circuit board by going through all steps mentioned above but in details.

According to (Shawn Wallace,April 2012) A schematic diagram, also called a circuit diagram can be defined as a standard way of describing the components and connections in an electronic circuit. It uses iconic symbols to represent components, with lines representing the connections between the components. It is not also a drawing of the actual physical layout in reality. Although drawing the actual circuit might be easier to understand,but when it comes to complicated circuits it won't be easy to track all wires in the circuit and how they are connected.

The left figure shows an example of a schematic diagram and the right figure shows an example of the translation of the schematic diagram into an actual circuit. The schematic is more abstract than the drawing, which gives you minimal information about each component.

As mentioned in the above definition that a schematic diagram consists of two things:

• Symbols that represent the components in the circuit.
  
  
• Lines that represent the connections between them.
  
  

According to (Paul Spinrad,January 2011) Each circuit component is represented by a symbol that indicates the general type of component and a label that points to (or directly lists) its particular specifications.

Here are some of the most common symbols used in circuit diagrams:

According to (Paul Spinrad,January 2011) Lines can have these properties:

• If a line runs between components, it means that they are connected.
• The connection can be a wire, a copper trace, a plug-socket connection, a metal chassis, or anything else that electricity will run through without much resistance.
• The length of a line also has nothing to do with the connection’s actual distance in real life.
• Schematics also distinguish between two unconnected paths and junctions. in unconnected paths, two lines crossing each other but not connected. in junctions, where the line crossings represent a shared connection.
  

The figure below shows schematics representing unconnected paths and junctions in both old and new conventions of schematics.

According to (Small Bear,2010) The solderless breadboard provides a way to build a circuit for testing purposes without committing to a permanent build.components can be easily replaced, and whole sections can be reconfigured as many times as necessary to get to a finished design.

According to (O'Sullivan,D. ,Igoe,T.,2004) the left figure above shows s a two-bus row breadboard. This breadboard consists of two long side rows and many horizontal rows separated by central divider . As mentioned, On each side of the board are two long rows with set of holes. All the holes in each of these lines are connected together with a strip of metal in the back as shown in the right figure above. These long rows are mostly reserved for the ground and 5Volts. You can also connect these two long side rows together using jumper wires to get many holes for both 5Volts and ground. In the center are several short horizontal rows of holes separated by a central divider. All of the holes in each row in the center are connected with a metal strip underneath the holes.The reason for the center divider is so that you can mount integrated circuit chips, such as microprocessors, on the breadboard.

This example was taken from article (Small Bear,2010) to illustrate how to build the circuit using solderless breadboard from schematics diagram. We will go step by step till the circuit is finished.

Step one: According to (Small Bear,2010) state that to cut off half the leads from a 10K resistor. Bend the leads flush to the body, and plug the resistor into any two convenient columns„ as shown in the figure below.

Step two: According to (Small Bear,2010) Plug the led in with its positive lead in the same column as the right-hand lead of the resistor as shown in the figure below

Step Three: According to (Small Bear,2010) plug multiple of jumber wires to the the two side rows of the breadboard to make the connections to the power supply busses as shown in the figure below. Also , connect a wire form the same column of the left-hand lead of the resistor to one of the holes of side rows that contain the positive connection of the battery. Another wire to connects the column containing the right-hand lead of the led to one of the holes of the side row connected to the negative side of the battery as shown the in schematic circuit.

After building the circuit using solerless breadboard. We need to check that all readings from the circuit are exactly as expected before committing to wielding. This can be achieved using Multimeter.

According to (Wiki,Multimeter) A multimeter is an electronic measuring instrument that combines several measurement functions in one unit as measuring potential difference (voltage) between two points Whether (AC/DC), current, and resistance.

According to (Wiki,Multimeter) there are two types of multimeters. These types are analog multimeters and digital mutltimeters.

According to (Wiki,Multimeter) analog mulitmeter can be defined as „Analog multimeters use a microammeter whose pointer moves over a scale calibrated for all the different measurements that can be made“.

According to (Wiki,Multimeter) digital mulitmeter can be defined as „display the measured value in numerals, and may also display a bar of a length proportional to the quantity being measured. Digital multimeters are now far more common than analog ones“.

According to (wikihow/Use-a-Multimeter)

• Set the meter for the highest range provided in case of reading AC Volts. For reading DC voltage try to Start high and work downward to the lowest range that can be safely displayed. Because is the meter is set to certain value and a higher value comes , then there is a probability to destroy the multimeter.
• „insert your test probes. Insert the black probe in the „COM“ or “-“ jack. Next, insert the red probe in the „V“ or „+“ jack„.
• Test a common electrical outlet by pressing the black probe into one of the straight slots and Inserting the red probe into the other straight slot. The meter should indicate a voltage very close to 120 or 240 volts (depending on type outlet tested).
• Remove the probes and rescale the meter again according to the nearest value to the value read with your multimeter (just above the value read).
• Reinsert the probes as previously and read an accurate value of voltage.

According to (wikihow/Use-a-Multimeter)

• It can be used to measure DC current,but sometimes for AC current as well.Set the meter to the highest AC or DC Amp range supported as in figure below.

• Insert the black probe into the „COM“ or “-„ jack and insert the red probe into the „A“ jack.
• Shut down the circuit. Open the portion of the circuit that is to be tested. An ammeter is placed in series with the circuit to measure current not across the circuit like voltmeter or the device will be damaged
• turn on the circuit and observe the value read by the multimeter. Then, adjust the ammeter like voltmeter to the nearest value that is just above the value read to get an accurate value of the current.

According to (wikihow/Use-a-Multimeter)

• The ohmmeter is used to measure the resistance of a component.
• As usual set the meter to the highest value possible and then reduce the meter to get accurate value reading.
• POWER CANNOT be applied to the component being tested.
• Connect the black test lead to the jack marked „Com“ or “-„. Then, connect the red test lead to the jack marked with the Omega (Ohm symbol) or letter „R“ near it.
• Hold the probes at the end of the test leads together.Then , according to the value read adjust the meter to the nearest value that is just above the value read to get accurate value of reading.

After debugging the circuit using multimeter and checking that everything in circuits as expected. Then, we have to commit to soldering on A Printed Circuit Board (PCB) to enter mass production,etc..

According to (aaroncake/solder) Soldering can be seen as gluing with molten metal which has a low melting point to adhere the surfaces to be soldered together.

According to (aaroncake/solder) when we commit to soldering we need two components which are The Soldering Iron and Solder.

According to (aaroncake/solder) is considered as source of heat.

According to (aaroncake/solder) the most common used soler is rosin core solder. It is is also desirable to use a solder with a diameter of 0.75MM to 1.0MM. Most solders used in electronics work are An alloy of 60/40 (60% tin, 40% lead).

According to (aaroncake/solder) The process of soldering goes as follows:

• Make sure that you got the solder that you got all equipment that i discussed in soldering equipment.
• Start heating the iron and when the iron is heated, start with cleaning the tip to remove old solder from it by using a wet sponge.
• coat the soldering tip in solder. This makes the tip transfer heat faster and easier.
• start by bending the leads and insert the component through the proper holes on the board.
• Put the tip of the iron on the pad so that it heats both the lead of the component and the pad of the circuit board. Heat them for a second or so before you apply solder. It is important to heat both the pad and the component otherwise the solder will simply pool and refuse to stick to the component.
• Touch the tip of the strand of solder to the component lead and solder pad, but not the tip of the iron. If everything is hot enough, the solder should flow freely around the lead and pad. Continue to add solder to the joint until the pad is completely coated and the solder forms a small mound with slightly concave sides.
• Trim the lead, use a small set of side cutters and cut at the top of the solder joint.

According to (André Knörig,Fritzing) „Frtizing is a software application which allows artists, designers and DIY-tinkerers to prepare their hardware inventions for production. Through an interface metaphor based on the typical workflow of the target group, Fritzing has proven its ability to provide useful support in the steps following the invention of an interactive artifact“.

According to (André Knörig,Fritzing) Fritzing offers three views on the circuit:

• A real-world-like breadboard view.
• A classical schematic diagram view
• A PCB (printed circuit board) design view.

building_circuits.pdf

• (Paul Spinrad,January 2011) Spinrad, P.(January 2011). Skill Set: Reading circuit diagrams, available at http://makezine.com/2011/01/25/reading-circuit-diagrams/
• (Shawn Wallace,April 2012) Wallace, S.(April,2012). Going from Schematic to Breadboard, available at http://makezine.com/2012/04/02/going-from-schematic-to-breadboard/
• (Small Bear,2010) Bear,S.(2010). Using A Solderless Breadboard, available at https://www.smallbearelec.com/HowTos/Breadboarding/BreadboardIntro.htm
• (O'Sullivan,D. ,Igoe,T.,2004),O'Sullivan,D. ,Igoe,T. , (2004),“Physical Computing„, available at http://www.hangar.org/docs/docs_lab/PhysicalColmputing.pdf
• (Wiki,Multimeter) „Multimeter.“ Wikipedia: The Free Encyclopedia available at http://en.wikipedia.org/wiki/Multimeter
• (aaroncake/solder) „How To Solder“ available at http://www.aaroncake.net/electronics/solder.htm
• (wikihow/Use-a-Multimeter), „How to Use a Multimeter“, available at http://www.wikihow.com/Use-a-Multimeter
• (André Knörig,Fritzing) ,knoerig, A.,Wettach, R.,Cohen, J.,“Fritzing – A tool for advancing electronic prototyping for designers„, available at http://fritzing.org/media/uploads/publications/Fritzing-TEI09-final.pdf