Building an electronic test and instrumentation system is a great way to get started in the field of electronics. Whether a beginner or an experienced professional, a well-equipped test system is essential for troubleshooting and repairing electronic devices.
This article will advise on building a complete electronic test and instrumentation system from scratch, including all the necessary equipment and tools.
Building a Test System
First, let’s look at the basics of building an electronic test and instrumentation system. You’ll need:
- A digital multimeter (DMM) for measuring voltage, current, and resistance
- Power supplies for providing power to electronic devices under test
- Oscilloscopes for observing waveforms
- Function generators for generating signals
- Resistance and capacitance substitution boxes for simulating components
You’ll also need a frequency counter, hand tools, and a way to find parts. So now that you know what’s required to build the test system, let’s get started.
Digital Multimeter (DMM)
A DMM is an essential tool for any electronics test system. It can measure voltage, current, and resistance, making it ideal for troubleshooting and repairing electronic devices. There are many DMMs on the market, so choosing one that meets your needs is essential.
Several types of multimeters exist. Bench units are the largest and most expensive but are also the most feature-packed. Portable units are smaller and less costly, but they don’t have as many features. Finally, handheld units are the smallest and most affordable but have the least features.
When choosing a DMM, consider the following factors:
- Accuracy: How accurate does the DMM need to be?
- Resolution: How much detail do you need to see?
- Bandwidth: What frequency range do you need to measure?
- Input impedance: What is the input impedance of the DMM?
A DMM is used to measure electrical values in voltage (volts), current (amps), and resistance (ohms).
DC Power supplies are necessary for providing power to electronic devices under test. Select a power supply that can provide the correct voltage and current for your testing devices. The power supplies you need will depend on the number of devices you need to test.
Do research before making your power supplies redundant by creating an automatic backup system. The voltage settings must match between connected units, along with other concerns.
An Oscilloscope displays waveforms of electronic signals and creates a graph of voltage changes over time. Oscilloscopes can display AC or DC. A multimeter measures a single value for voltage, but an oscilloscope is needed for more complex circuits.
Bandwidth is necessary to know when choosing an oscilloscope. It is the range of frequencies that the scope can display accurately. As frequency rises, the unit’s ability to display the signal decreases. Rise time is the time it takes the scope to display the signal. A faster rise time means the scope can display a changing signal more accurately.
The sample rate is samples per second, determining how often an oscilloscope reads the signal. A higher sample rate creates a more detailed waveform. Waveform capture rate is waveforms per second which shows how fast the oscilloscope acquires waveforms.
Memory depth is the number of samples the scope can take before writing over the first sample. A deeper memory allows the oscilloscope to capture longer events.
A function generator produces electrical waveforms, which you can use to test electronic devices. Function generators are available in different models that can generate different waveforms.
The most common type of function generator is the sinusoidal waveform generator. This type of generator produces a sine wave. Sine waves test electronic devices that use AC power, such as motors and transformers. Square waves, sawtooth waves, pulse, and triangular waves are other options.
A function generator can be a benchtop instrument, a rack-based instrument, a USB function generator, or a computer-based function generator.
Resistance and Capacitance Substitution Boxes
Resistance and capacitance substitution boxes help simulate components. They can help you troubleshoot electronic devices by allowing you to test them with different resistance and capacitance values.
A frequency counter measures signals’ frequency and time between digital signals. These units often measure oscillation cycles or pulses per second in a signal.
Hand tools are necessary for repairing electronic devices.
Buy a set of standard screwdrivers and a set of miniature screwdrivers for disassembling consumer electronics. Needle-nose and lineman pliers are good for dealing with different gauges of wire.
Make sure you purchase a wire cutter for working with electronics that can cut wires on a PCB. Wire strippers are essential when working with electronics. Buy dedicated wire strippers instead of relying on strippers combined with pliers.
Purchase a crimping tool if you’re adding connectors to cables, and make sure it’s designed for electricians. A helping hands device with alligator clips and a magnifying glass is a lifesaver when you’re trying to connect small wires together. These clips will hold the cables so you can solder them.
A rotary tool is nice to have on hand for various jobs that may come up and lets you drill PCBs and create holes in plastic boxes.
When you’re building an electronic test and instrumentation system, you’ll need to be able to find parts. You can find electronic components everywhere online. If you want to buy parts from US stores, look at Amazon, DigiKey, Parts Express, and Tayda Electronics.
Make a list of what you need before you start shopping around to save you time and money. Buying in bulk costs less than buying individual parts. You can also find parts at local electronics stores, salvage yards, or online auctions.
After you obtain the components, it’s time to put them together. Begin by deciding what kind of system you want to build. Do you want a benchtop system or a portable system? Will you be using it for general testing or specific tasks? Once you know what you need, start assembling your system.
Begin by setting up your power supply. Then add your oscilloscope, function generator, and frequency counter. Next, connect the parts with cables. Be sure to use the proper type of cable for each connection. Finally, add any other parts or accessories you need, such as a multimeter or resistance and capacitance substitution boxes.
Test Your System
Once you have assembled your system, it’s time to test it. Begin by testing each individual component. Next, make sure everything is working correctly.
Once you’ve done that, start testing your system as a whole. Try different combinations of settings and see how they affect the results. Be sure to document everything you do so you can replicate your results later.
Things To Consider
Here is a list of things you should consider when building your own electronic test system from start to finish.
Purchase a Workbench
You do not want to solder on the kitchen table and get chemicals everywhere. Instead, get a cheap bench at IKEA or something similar. If you want something more durable, look into getting a heavier-duty workbench from a company like Gladiator.
Organize Your Equipment
Get some storage containers to keep all of your equipment and components organized. You can find these online. Look for something that will fit on your workbench and has multiple compartments, which will help you keep everything within reach.
Purchase a Parts Kit
This kit can be beneficial, especially when you are first starting. A parts kit will have a variety of essential components that you can use to build circuits. It’s an excellent way to begin without purchasing each component individually.
Join an Online Community
Many online forums and communities are dedicated to electronics, which is a great way to learn from others and get advice on building your system. You can also find tips and tutorials.
Learn About Safety
Working with electronics can be dangerous, so educate yourself on the proper safety procedures. Always disconnect power before beginning a project. Use caution when soldering, as the fumes can be harmful. Keep your work area organized to prevent accidents. Have a fire extinguisher on hand in case of an emergency.
Read Some Books
There are many excellent books available on electronics and electrical engineering. These can be great resources for learning more about building a test system. There are also courses online that can teach you the basics of electronics.
The best way to learn is by doing, so experiment and try new things. You never know what you might discover.
Building an electronic test and instrumentation system can be a rewarding experience. It’s a great way to learn about components and how they work together. It can save you money long-term by allowing you to test and repair your own electronic devices. You can develop a system that meets your specific needs with patience and hard work.
Now that you understand how to build an electronics test system from scratch, you’re ready to start. First, choose the equipment and tools you need, and then find a way to get parts. Then, you’ll have a complete test system ready to use with a little effort.