What is Electronics Development

1. Requirements

First and foremost, it’s important to have a good understanding of the customer’s expectations and requirements. Electronics development can become costly if it turns into a search for the right solution. If the requirements are not yet on paper, that is the first step. Both the customer and the electronics developer must carefully consider the consequences of adding or omitting a requirement. Both can result in additional work.

1.1 Functional Requirements

The functional requirements describe on an abstract level what the solution must do.

For example, for a 1-phase power analyzer:

• Measuring AC voltage and current of 1 Phase (range 85 - 270Vac)
• Determination of

1. power
2. power factor (cos-Phi)
3. energy (kWh)

• 1 Single-phase input
• 1 Single-phase output
• 1 RJ45 Ethernet connection
• Logging of Vrms, Irms, Pre, Pim per line-cycle (20ms / 16.67ms)
• Readout via Ethernet

The Ethernet port accepts DHCP and the logging sends data as UDP via Ethernet.

1.2 Required Certifications

Every device brought to market in the EU or other countries must comply with a number of standards. For Europe, the CE directive 2014/30/EU applies. For electronics, this almost always means that EMC standards must be met. Depending on the application, other standards may also apply, e.g. regarding safety. Only looking at the electronics is not enough to determine if the entire product complies. Ultimately, the final product must comply, and the manufacturer (usually you) issues a certificate of conformity for it.

For the electronics, it must be determined which standards are applicable and can influence the design. The designer can then take this into account during development.

2. Development Phase

This is the phase of electronics development in which the schematic, the printed circuit board, and any special components are created. This phase can be subdivided into further analysis, the global design, the detailing, and the implementation. This phase of electronics development results in the delivery of a prototype.

2.1 Analysis

Based on the product requirements and standards, the risks are mapped out and an FMEA¹ (Failure Mode Effect Analysis) is created. This does not always have to be formal, but it is important to think in advance about what should happen if something goes wrong.

In our example:

Failure	Effect	Severity [0-9]	Action
Ethernet disconnect	UDP Data not sent	0	store results
Phase wire open	No load current	1	Alarm

The design can now be optimized so that the ‘Severity’ is sufficiently low.

Safety

Safety aspects can also be made transparent through an FMEA. Often there are also standards that the device must comply with that impose special safety requirements.

2.2 Global Design

Once the analyses are completed, the global design follows. A layout of the required blocks is made, and it is checked whether the functional block distribution is logical and has no adverse side effects. Safety aspects and possible failures can also be taken into account here.

2.3 Sensors

Sensors often require special processing. With industrial sensors, that processing is already built-in, which can be reflected in the price. Costs can be saved by connecting the sensor directly to custom electronics.

2.4 Actuators

The same principle as for sensors also applies to actuators. Sometimes the use of control electronics is favorable instead of, for example, a relay. It often provides more possibilities for optimizing the actuator. Take, for example, a device with a number of DC motors. The control can be done with a relay, even bidirectionally. However, with a transistor control with underlying software, a soft-start and soft-stop can be realized. This is not possible with a relay.

3. Electronics Implementation

The ideas from the global design are now turned into reality. Schematics are drawn and printed circuit boards are designed. The printed circuit boards are built so that the embedded software (firmware) can be tested. Depending on the application, a provision must be made for updating the firmware. For applications with built-in communication (wired or wireless), this saves a lot of time in use because the update can take place remotely.

4. Electronics Qualification Phase

Qualification is the process of checking whether all requirements are actually present in the prototype and working correctly. A lot of attention must be paid to out-of-range and/or error situations. All measurements are documented so that it can be demonstrated later that the test was carried out and what the result was.

4.1 Mechanical Fit

Ultimately, the control electronics also need to be installed somewhere. For the connection of the connectors and the height of the components, a check of the mechanical fit is necessary. This can lead to small adjustments. If the design has already been checked on the computer via 3D drawings, the chance of adjustments is smaller.

5. Acceptance Tests

Subsequently, the customer is involved in the process again. The customer must convince themselves that the product meets the specified requirements. Many customers are not as sharp as desired on this point. They believe that the developer should have done their job well, but forget that they are the experts in their field, and the developer must primarily adhere to the requirements. A difference can arise here.

Often at this point, the physical device is brought to life with the electronics for the first time, and small points often arise that require further coordination. This can be timing or compensating for mechanical effects.

An endurance test under varying conditions is also highly desirable.

5.1 Fault Situations

In the acceptance tests, introducing fault situations is an important phase. By simulating as many fault situations as possible, it can be checked whether the control system handles them correctly. In practice, a developer tests the ’normal’ situations more often during electronics development and less often the fault situations.

6. Production Preparation

If the prototype did not require any changes, production can often be started directly. Otherwise, it is wise to do a pre-production or a 0-series. Such a 0-series is then a limited number, for example 10 to 25 units. If something serious still went wrong, the damage is at least manageable. If 1000 or 5000 printed circuit boards have already been produced, the costs for repair or, worse, replacement are very high.

6.1 Production Test

For every production, the result must be tested. After all, errors can have been made, such as the mounting of a wrong component. However, it more often concerns soldering errors. In that case, a component is not properly soldered, or a short circuit from solder tin has occurred. There are 2 levels of tests:

• Functional test
• Specification test

In many cases, a Functional test is sufficient, but for devices that are going to far-off countries and where service and repair are expensive, a test system that also tests the specifications can be more cost-effective. Testing on specification means, for example, measuring the frequency characteristic of analog inputs. With only a functional test, a faulty component in this path may not become visible. This increases the damage.

For the production of larger numbers, a bed-of-nails tester is often made. An automatic test is performed with this. The test electronics are often more extensive and complex than the produced product.