Build circuits yourself

Build your own circuits

For the real (starting) electronics engineer, hobbyist and professional it is a challenge to build an electronic circuit working on a pcb board assembly, so we will discuss here how you can do that.

Building a working circuit on a PCB yourself consists of 3 steps:

- Choice of electronic circuit

- What kind of printed circuit board do you use (experimental print, print etching or have print made)

- Provide the printed circuit board with components and tests

Manufacture of a printed circuit board

By manufacturing the printed circuit board we mean transferring the electrical schematic to an epoxide printed circuit board. After the printed circuit board has been manufactured, the components can be placed on the printed circuit board and soldered. After we have chosen an electronic circuit, we will have to determine which method we want to use to actually build our circuit on a print, there are several options for this:

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- On experimental print (also called "hole print") or breadboard

- Etch a print yourself (“printed print”)

- Have a print made by a company (“printed print”)

Building on an experimental print works quickly and cheaply, it doesn't look professional but works just as well, and is perfect for testing a circuit before making a printed version of it. Making a printed print yourself takes a little more work, is slightly more expensive, but gives a lot of satisfaction from your work. Before we start making a print, we need a print layout, which determines where and how the components are placed and how the connections (print tracks) run. There are also companies that turn your print layout into a professional printed print, if you need several of the same prints, this can even be cheaper than manufacturing it yourself.

What is an electrical circuit?

An electrical circuit is a device that uses electricity to perform a task, such as running a vacuum or powering a lamp. The circuit is a closed loop formed by a power source, wires, a fuse, a load, and a switch. Electricity flows through the circuit and is supplied to the object that powers it, such as the vacuum motor or light bulb, then the electricity is returned to the original source; this return of electricity enables the circuit to keep the flow of electricity flowing. There are three types of electrical circuits: the series circuit, the parallel circuit, and the series-parallel circuit; depending on the circuit type, electricity may continue to flow if a circuit stops working. Two concepts, Ohm '

How it works

Most appliances that run on electricity contain an electrical circuit; When connected to an energy source, such as plugged into an electrical outlet, electricity can flow through the electrical circuit in the appliance and then return to the original energy source to continue the flow of electricity. In other words, when an on / off switch is turned on, the electrical circuit is complete and current flows from the positive terminal of the power source, through the wire to the load, and finally to the negative terminal. Any device that consumes the energy flowing through a circuit and converts that energy into work is called a load. A light bulb is an example of a load; it consumes the electricity of a circuit and converts it into work - heat and light.

Types of circuits

A series circuit is the simplest because it has only one possible path that the electric current can flow; if the electrical circuit is broken, none of the chargers will work. The difference with parallel circuits is that they contain more than one path for electricity to flow, so if one of the paths is broken the other paths will continue to work. A series-parallel circuit, however, is a combination of the first two: it attaches some of the loads to a series circuit and others to parallel circuits. If the series circuit breaks, none of the loads will function, but if one of the parallel circuits breaks, that parallel circuit and the series circuit will stop working while the other parallel circuits will continue to work. Also visit our printed circuit board assembly

Ohm's law

Many "laws" apply to electrical circuits, but Ohm's Law is probably the best known. Ohm's law states that the current of an electrical circuit is directly proportional to voltage and inversely proportional to resistance. So, if the voltage increases, for example, the current will also increase, and if the resistance increases, the current will decrease; both situations directly affect the efficiency of electrical circuits. To understand Ohm's law, it is important to understand the concepts of current, voltage, and resistance: current is the flow of an electric charge, voltage is the force that drives current in one direction, and resistance is the opposition of an object to having flow through it. The formula for Ohm's Law is E = I x R, where E = voltage in volts, I = current in amperes and R = resistance in ohms; this formula can be used to analyze voltage, current, and resistance of electrical circuits.

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Source voltage

Another important concept related to electrical circuits, source voltage refers to the amount of voltage that is produced by the energy source and applied to the circuit. In other words, source voltage depends on how much electricity a circuit will receive. The source voltage is affected by the amount of resistance within the electrical circuit; it can also affect the amount of current as the current is usually affected by both voltage and resistance. However, resistance is not affected by voltage or current but can reduce the amounts of voltage and current to an electrical circuit.

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How to add a simple circuit to your Arduino

 The Arduino is a fantastic development board for testing ideas and products, but unless you learn how to connect it to external circuits, it is rather pointless! In this article, we will learn how to do just that!

External Devices and Circuits

Some of the strongest features of the Arduino are its GPIO pins, which allow it to send electrical signals to the outside world and read them! But using GPIO is a two-part problem; you must deal with it correctly in both hardware and software! So, to start, let’s look at the hardware side of external connections to the Arduino.

Most Arduinos have pin headers on the outer perimeter, which are used to connect to circuits. These pins can have many different functions, including I2C, SPI, and UART, but they are usually used in one of two modes: digital input and digital output. When configured as a digital input, the pin can read digital values from a wire, and these values can either be 1 or 0, which correspond to VCC and 0V, respectively. When configured as a digital output, the pin can set the digital value on a wire. So, if the pin is instructed to write a digital 1, the Arduino will set the voltage on the wire equal to VCC (typically 5V), and if the pin is instructed to write a digital 0, then the voltage will be set to 0V. In this how-to, we will learn how to turn an LED on and off, as well as how to read the state of an external button (all connected on an external breadboard).

Before you connect a circuit to the Arduino, you need to determine if protection circuitry is needed. If the proper protection and/or driving circuitry is not used, you run the risk of permanently damaging the Arduino. So, let’s see how to protect our Arduinos properly!

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Input

If you are using a GPIO pin as a digital input pin, you need to find out the maximum and minimum voltage that the pin can handle. The easiest way to determine this is to either consult the Arduino forum or find the datasheet for the main controller and read its I/O pin tolerances. For example, the Arduino Uno is based on the Atmega328, and, if we consult the data sheet, page 365 has a table of electrical characteristics. The third row mentions that the maximum and minimum input voltage for any pin (except RESET) is -0.5V to VCC+0.5V. This means if our Arduino uses a 5V source, then the maximum input voltage is 5.5V and the lowest is -0.5V.

If you accept that your input may go beyond these ratings, you can use clamp diodes to clip the voltage when it goes beyond these values. Below is a simple circuit example of a single resistor and Zener diode that can be used to protect inputs from accidental damage and ESD. The resistor is used to limit the current flowing to the Arduino, should something horrible happen! This circuit is not needed in many projects, but, for those who want to add just that little extra bit of protection, it is not a bad idea. Also, check out pcb prototype assembly service

Output

Connecting an Arduino pin to an output device also requires a lot of care, and the first rating you should check is the expected current draw. The Arduino Uno pins are rated to a maximum output current of 40mA, but this does not mean that, if an external circuit attempts to draw more, the Arduino will refuse. Instead, the Arduino will happily give out as much current as it can, but this will very quickly result in the device overheating and killing itself.

This is why you need to find out how much current your external circuit wants! If it is equal or less than what the Arduino is rated to give out, you should have no problems connecting the Arduino directly to the circuit. If, however, the circuit needs more, you will need to use some kind of transistor-driving circuit. The circuit below shows a relay, which is controlled using a transistor that is controlled by an Arduino output pin.

You will also need to consider is the circuit itself! The number of times people have connected LEDs to an Arduino output without a series resistor is frightening, and it can damage both the LED and the Arduino! So, make sure that any current-drawing device that is directly connected to an Arduino output pin has some kind of series-current-limiting resistor!

Basic Arduino Circuit Example

Now that we know what to look out for when connecting external devices to the Arduino, we can go ahead and create our circuit. The circuit uses an LED with a series resistor connected to pin 2, while a tactile switch is connected to pin 3. A pull-up resistor is also used on pin 3 so that, during normal operation, pin 3 is connected to VCC through the resistor. But, when the button is pressed, the voltage seen by the pin will be 0V. This means when the button is not pressed, the pin sees a digital 1, and when the button is pressed the pin sees 0.

The Software Side

With the hardware built, it’s time to create an Arduino sketch that will make the LED flash when the button is pressed. First, start the IDE and then create a new project/sketch, which we will call “Arduino Button Flasher”. With the sketch made, it’s time to put in some code.

Now, using IO pins on the Arduino is incredibly simple, and it only requires a few functions:

pinMode(pin, in/out)

digitalWrite(pin, value)

digitalRead(pin)

The first function you will need to use is pinMode, which is used to declare whether a pin is an INPUT or an OUTPUT. The code example below shows how pins can be configured as such.

The second function you will need to use is digitalWrite, and this is used to write digital values to a pin.

The third function you will need to use is digitalRead; this is used to read the digital value present on a pin.

Code Example

Now it’s time to upload the code below to the Arduino! The external switch should make the external LED flash five times!

The beauty of-four layer PCBS

Four-layer PCBs are something that makers have long known about but almost never gotten involved with. However, with the introduction of PCB prototyping facilities around the world, and widely available CAD packages, four-layer boards are now within the reach of makers. But what are four-layer boards and how can they help you with your next project?

Since their early days, makers have mainly been limited in circuit construction techniques. Breadboards provide makers the capability to reuse components, while stripboards allow for permanent fixtures. Printed Circuit Board assembly has also been available to makers, but mostly in the most crudest of ways (using the toner transfer method). These circuit boards remove the need for wires (especially double-sided boards) but they are lacking in features such as through-hole plating and silkscreen. However, new fabrication houses have led to high-quality prototyping PCBs at low prices (as low as $2 for 5 pieces).

The result is that maker projects can now integrate SMD devices, including QFN and BGA packages, which allows for miniaturized designs and more complex circuits. But not only are double-sided PCBs available to makers, so are four-layer PCBs! Most designs by makers will be suitable for two-layer boards, which may leave many to think, “Why would I want to use a four-layer board?”.

To understand the advantages of four-layer boards, it’s important to first understand the difference between two layers and four-layer boards. As the name suggests, four-layer boards have four separate copper layers that can be used for routing and power, whereas two layers only have two copper layers. Therefore, the first and most obvious advantage of four-layer boards is that there are two additional routing layers for signals, which allows for reduced PCB sizes (as well as the ease of integrating complex devices such as BGA that may have as many as 200 connections). Get more PCB box build assembly services

Four-layer boards are also advantageous for makers who have an interest in selling their designs. Electronic products that are sold commercially are legally required to be certified by either FCC or CE regulations, and these regulations include emissions that essentially require that circuits to not emit radio energy over a specified value. Two-layer designs can struggle with emissions control, but four-layer PCBs can utilize power planes and ground planes shielding to absorb .emitted mission from traces.

Four-layer PCBs also allow for signals to be routed inside the PCB stack and have ground planes on the top and bottom layers, but it is more common for the two inner layers to be power and ground. The four-layer arrangement can also make signal routing easier, in that power and ground connections can be removed entirely from the signal routing layers and therefore free up space for signals.

Four-layer PCBs do have some drawbacks that can make using them difficult. Firstly, four-layer PCBs are more expensive, which may make them impractical for simpler designs. Secondly, four-layer PCBs can hide traces in their inner layers which can make circuit debugging very difficult. In the event that a circuit requires debugging, it would be more practical to rely on the CAD drawings of the designs instead of following traces on the PCB, but this can also work as an advantage. The use of four layers can be a deterrent against an engineer's reverse-engineering your design, as hidden layers are virtually impossible to see (only x-rays can be used to see these inner layers).

Four-layer PCBs can help miniaturize your design, improve its EMI performance, and allow for more complex routing. While they are rather advanced (thanks to the low cost of PCB fabrication currently available to makers), it would not be a bad idea to test them out to see how they can be beneficial to your next project.

What is an embedded system?

Embedded systems are hardware solutions that are combined with specific software control. They are tiny systems that have memory and can calculate and measure.

In addition, they send a signal when necessary. They are integrated into everyday devices that can therefore display intelligent behavior. This way you guarantee safety and ease of use and increase the connectivity of an electronic product. Read more PCB board assembly.

An embedded system is also referred to as an integrated system or an embedded system. Some examples of devices that contain these systems:

• Phones: updates that provide new functions
• Doorbells: with camera and recording functions
• Alarm systems: send different signals
• Smart thermostats: take the weather and where you are into account (geofencing)
• Fridges: that pour voice-controlled water for you
• Door locks: remotely lock and unlock

Software integrated in hardware

Measurement and control systems in electronic products ensure that a machine, tool or device does what it is supposed to do. In other words, these products must be able to perform the operations for which they are intended.

Previously, electronic measuring and control systems consisted entirely of hardware. An embedded system consists of both hardware and software.

Thanks to embedded systems, software (intelligence) are now increasingly found in devices (hardware). This gives the possibility to add or adjust functions within the same device. 

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Application of embedded systems

Embedded systems are increasingly used in machines and tools, but also more and more in everyday devices: from fragrance dispenser with timer to smart plugs and lamps. On the one hand because these systems are becoming cheaper and on the other hand because these systems are becoming more accessible and easier to process.

As a result, there is now a great diversity of embedded systems on the market. Both for large and small equipment. In addition, you will increasingly find embedded systems in hospital equipment and robots in healthcare.

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5 Things To Consider For Box Build Assembly Process

Box-build, which is also referred to as systems integration, is an assembly work other than a printed circuit board (PCB) production. It is an electromagnetically assembly process, which includes enclosure fabrication, installation and routing of cabling or wire harnesses, and installation of sub-assemblies and components. The box build can mean a PCB Assembly (PCBA) in a big cabinet full of wires, or a small enclosure, or a complex fully integrated electro-mechanical system with pneumatics and electronics.

What does the Box Build Assembly Services Include?

Box Build Assembly Services include:

System Level Assembly

Product Assembly

Sub-Level Product Assembly

Packaging & Labeling

Testing

Software Loading and Product Configuration

Aftermarket Service and Depot Repair of EIT Built Products

Warehousing, Order Fulfillment, and Traceability

Things to Consider for Box Build Assembly Process

If you are considering a box build assembly process in the near feature, following are some of the factors that you should keep in mind. You can support the assembly services provider by providing the following information.

Box Build Assembly

Bill of Materials (BOM): This is a very important requirement for any Electronic Manufacturing Services (EMS) provider. This helps them get an idea of all the key components, and is required to clearly mention the materials to be sourced by the EMS provider. It should also explain appropriately, what will be issued free from you. You should decide whether you want to define the smaller items, such as tie wraps, adhesives, nuts and bolts, heat shrink, washers, and so on. The same is applicable for wires and their identifiers. While these are considered as consumables, you should always remember that they still have a price and need buying. Thus, they must be defined to avoid unexpected production delays and cost boosters.

Assembly: If possible, you should provide 3D CAD models. This helps to visualize the final product. There are a number of CAD packages that offer free drawing viewers. Many advanced EMS providers possess CAD packages that enable easy conversion of drawings into build instructions, as well as updates, if needed. A layout drawing with the information of key components should be included.

Sample Unit: A sample unit is always helpful, and can be the key source of data if the drawings are unfinished. In this situation, you will certainly need a provider that can plan and create the drawings for you to guarantee reliable builds.

Dimensions: You should always inform the EMS provider about the size and weight of the unit. This is essential not only for shipping, but also handling and storage throughout the complete build process. You should also consider and decide how you need the completed product to be packed and transported.

Testing: In case of electrical systems, you should specify basic electrical safety testing, such as earth bond and flash tests. Are you willing to perform certain functional testing, or factory acceptance testing prior to shipment to an end customer? Or just the visual inspection sufficient? To answer these questions, you should take advice from EMS provider if necessary, as they will have the proper knowledge and good experience of what works best.

Whether your design needs a simple, straightforward box build assembly or a more complex assembly, providing the precise data up front. It makes sure that you get to start from a good place where everyone knows what is required.

What information do I need to outsource a box build assembly?

Outsourcing an electronic printed circuit board assembly (PCBA) is usually a simple and well defined process. Just hand over the Gerber files, the CAD and a bill of materials (BOM) and away you go.

Box build, or top level assembly, on the other hand, can be less well defined. A box build can mean many things - from a PCBA in a small enclosure, to a large cabinet full of wires, or a complex fully-integrated electro-mechanical system with electronics and pneumatics.

So what are the basics you will need to consider to get an accurate quote and help the build process go smoothly with your electronic manufacturing services (EMS) partner?

Materials

The first thing your EMS provider will ask for is a BOM. This should include all the main components and should clearly define what materials the EMS provider will source and, where appropriate, what will be "free issued" from you.

You'll also want to think about what to do with the smaller items: the nuts and bolts, washers, tie wraps, heat shrink, adhesives and so on. Are you going to define these, or let your supplier decide?

The same can go for wires and their identifiers. While these are often considered consumables, they still have a cost and need purchasing, so must be defined somewhere to avoid unexpected cost increases and/or production delays.

Component drawings, particularly for "drawn" or bespoke items, should have tolerances and finishes clearly specified. Leaving these things open to interpretation could cause problems with assembly or quality control later - so it’s best to specify exactly what you need.

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Assembly

Where possible provide 3D CAD models, as this helps to visualise how the product goes together. Many CAD packages offer free drawing viewers.

More advanced EMS providers are likely to have their own CAD packages to help convert drawings into build instructions (and to enable them to update the drawings if required and agreed by you). 

A layout drawing showing where major components will go - routing of cables and so on - should also be included. This might be important to you for servicing, for example, or for design compliance reasons.

Ideally too you will be able to provide detailed build instructions - and particularly in the case of an existing product that is already being manufactured.

This may not always be so straight forward, however, if a product has been manufactured "in house".

And for new products, some systems are so complex that it can be challenging to complete a design on paper, or even in 3D CAD.

Sometimes an element of design and development has to happen as the first products are made.

When a large amount of labour, space or specialist tools are required, it can make sense to outsource prototype builds rather than build them in house.

It also gives your assembly partner a chance to learn about the product and to hit the ground running when full production starts. Naturally you’ll need to choose an EMS supplier that can assist with this development rather than just "build to print".

For electrical systems, schematics (circuit diagrams) will be required.

Your manufacturing partner should decide on the best build method (for example whether to opt for point to point wiring or pre-prepared cables/looms) and they will produce cutting lists accordingly.

Again, try to provide these in an electronic format whenever possible.

A sample unit is always helpful, and can often be the main source of information if the drawings are incomplete. In this case though you’ll definitely need a provider that can engineer and create the drawings for you to ensure consistent builds in future.

Let your EMS provider know the size and weight of the unit. This is important not only for shipping but also storage and handling through the build process.

You also need to consider how you need the finished product packed and transported; do you need special boxes or a standard shrink wrap and pallet, for example?

Test

Last – but certainly not least – think about test. For electrical systems you should at the very least specify basic electrical safety testing - e.g. earth bond and flash tests.

Consider too whether you may want them to do some functionality testing as well, or perhaps factory acceptance testing by your staff before shipment to an end customer.

Or perhaps a visual inspection will be sufficient?

Seek advice from your EMS provider if required, as they will have the knowledge and experience of what works best.

Outsourcing box build assembly inevitably requires close cooperation between customer and suppliers. It can also tend to be an evolving process as a new product goes into manufacture.

But by providing the right information to your EMS partner, at the very start, you’ll have the peace of mind of knowing that everyone understands what is required.