Breadboard with NI ELVIS III

Throughout your engineering study, you need to learn electronics spanning from analog, digital and power. To gain the appropriate foundation knowledge, you use breadboard activities to ensure you understand the underlying physics of electronics before proceeding to further advanced topics that will be critical in mechatronics systems, controls, communications, and power. For many students, using the breadboard is the first hands-on experience in translating the abstraction of circuit theory to the real world. In this article, you will be provided with an in-depth explanation of the breadboard experience, key terminology, and tips-and-tricks to ensure that you understand how to breadboard efficiently.

What is a Breadboard?

There are three methods for building circuitry: solderless breadboard; solder breadboard; and printed circuit board (PCB). The solderless breadboard is a reusable base that allows you to build electronics without the need to solder. On this base, you can easily connect electronic devices (such as capacitors, resistors, operational amplifiers), wire them together into a specific topology, and investigate performance with instrumentation. The solderless version of the breadboard makes this base completely reusable and requires no solder to make connections between devices and wires. The solderless breadboard has a limitation, and we will discuss when you should use the solder breadboard and PCB in a later section.

The NI ELVIS III Prototyping Board which is provided with NI ELVIS III has four solderless breadboards integrated to rails on either side of the breadboard space. These rails connect to NI ELVIS III via a PCI connector and deliver signals for input and output to the circuitry being built.

Due to this, there is no direct connection between the NI ELVIS platform to the breadboards, but instead, you can access the signals from the workstation by connecting jumper wires from the Control I/Os to the breadboards or use the NI ELVIS instruments.

Figure 1
 

Inner Workings of a Breadboard

To understand how a breadboard works, let’s take a moment to define the breadboard terminology and look how it is constructed.
 

Sockets

Sockets are holes in the board with a spacing of 0.1” between the two closest holes. Inside each socket,  there is a metal clip that secures the component lead when you insert it into the hole. A clear breadboard in Figure 2 shows the metal clip beneath the socket hole.
 

Bus Strip

There are four bus strips, two on each side with the label + and –.  The bus strips are also commonly called power rails because you usually connect power and ground signals to it.  The bus strip on the ELVIS board is made with one piece of metal, unlike some breadboards that you can buy where each strip is made with two pieces of metal.

Figure 2
 

Terminal Strips

The area where you build your circuit is referred to as a terminal strip. There are sixty-four rows divided into 10 individual strips named A, B, C, D, E and F, G, H, I, J. These rows are separated by a center divider (explained below). For each row, the strips A, B, C, D ,E are electronically connected to a node. Similarly, F, G, H, I, J are connected into a singular node. This allows you to appropriately connect wires and devices without having to use one socket for multiple items.
 

Center Divider
The spacing between the socket E and F is the center divider. It was designed with enough spacing for you to place a dual-line integrated circuit (IC) that would connect across the center divider and connect into the appropriate strips (A-E or F-J).

Figure 3
 

Underneath the Hood of the Breadboard

Figure 4
 

The image above shows the bottom side of the breadboard with the protective sticker removed to illustrate the construction of a breadboard.

You can see the power rails (or bus rails) are the long vertical metal strip. The terminal strips are the shorter horizontal metal strips. The center divider can be seen in between the terminal strips. As you can see, in each of the bus-rails and terminal strips there is a singular metal/conductive segment that creates the signal path and nodal connections.
 

Building Your Circuit

Using the above information we are now able to begin translating our knowledge of how to build a circuit prototype. We will be able to understand how to:

• Use the Bus Rails or Power Rails to connect input signals, output paths or ground.
• Use the Terminal Strips to connect our circuit topology by using each row as an electrically connected node.
• Use the Center Divider to place an integrated circuit (such as an operational amplifier) effectively.
• Connect instruments to the circuit to supply signal and make measurements.
 

How to Build a Circuit on the NI ELVIS III Prototyping Board

In this example, we will translate a circuit schematic step-by-step (in this case using Multisim Live ). You will need the following components to follow along with this tutorial:

• Two 1 kΩ resistors
• One OP482 opamp
• Jumper wires

Figure 5 is an inverting operational amplifier circuit that requires power sources, ground, resistors and integrated circuitry. You will also notice that there are nodal connections between R2, R1 and the U1 devices. They will all connect at a single node which will require usage of the terminal strips.

Figure 5
 

Figure 6 shows the inverting amplifier circuit on the breadboard. Follow the steps below to connect this circuit.

Figure 6

Ensure the power to the prototyping board is off while you connect the circuit.

1. Begin by considering the U1 device. This is an OP37 integrated circuit (IC), which we will be placed on the breadboard

•  You can download the datasheet to learn the pinout for an OP37 device so that you can translate the symbolic representation with the actual real-world IC.  The figure below is from the Analog Devices' datasheet, you can download it at http://www.analog.com/media/en/technical-documentation/data-sheets/OP37.pdf.  Component pinout (pins 1-8) map to the schematic pin number for U1 in Figure 5.

• Place the IC in sockets E and F as shown below. As you can see you have placed it over the center divider and four of the pins are connected into rows 16 – 19 in strips E and F respectively.

Figure 8
 

• On top of every IC, there is a pin 1 indicator which is usually a small circle or a notch as in this case. Make sure you know which pin is pin 1. In this case pin 1 is in row 20, terminal Strip F.Based on this configuration, you will see that pins 2 to 8 are available in a counter-clockwise direction based on the placement in Figure 8.
• Based on this configuration, you will see that pins 2 to 8 are available in a counter-clockwise direction based on the placement in Figure 8.

IC Pin	Breadboard Placement	IC Pin	Breadboard Placement
1	Row 20, Terminal Strip F	5	Row 17, Terminal Strip E
2	Row 19, Terminal Strip F	6	Row 18, Terminal Strip E
3	Row 18, Terminal Strip F	7	Row 19, Terminal Strip E
4	Row 17, Terminal Strip F	8	Row 20, Terminal Strip E

 

• Connect the power and ground signals to the power rails. You need +15V, -15V and analog ground AGND for this circuit. As you will see in Figure 9, the NI ELVIS III Prototyping Board includes power and other I/O connections. To power our circuit, we need to bring the +15V, -5V and AGND connections from the NI ELVIS III Control I/O to the breadboard.

Figure 9
 

• We are going to use the power rail that is closest to the IC power pin. In this case, you will see that we are taking our -15V power to the positive power rail towards the left side of our IC configuration. Place a jumper wire from -15V bank to the + strip on the right side.

Figure 10
 

• Next, we are going to connect the analog ground (AGND) to the bus strip on the right side of the IC configuration. Place a jumper wire from AGND bank to the negative (-) bus strip on the right side.

Figure 11
 

• Let’s now connect our +15V bank to the power rail towards the left of the IC. Place a jumper wire from the +15V bank to the positive (+) bus strip on the left side.

Figure 12
 

• We are now ready to connect our IC to these power rails. The analog ground (AGND) is now connected vertically to the negative power rail. To bring that signal to our IC we will bring an additional jumper wire from the – rail to row 18, terminal strip J. This is now also connected to pin 3 of the IC.

Figure 13
 

• Connect the -15V source to the IC pin 4 by placing a jumper from the + rail to row 17, terminal strip J.

Figure 14
 

• Finally, let’s connect the +15V source the IC pin 7. To bring that to our IC we will bring an additional jumper wire from the left + rail to row 19, terminal strip A.

Figure 15
 

3. The next step is to connect the input resistor (R1) and the feedback resistor (R2) to complete the circuit connection.
   • The 1 kΩ input resistor R1 is connected to the non-inverting amplifier pin on one end, and the other end is to connect to the function generator. Place one end of a resistor in row 19, terminal strip G, and the other end to an unused terminal strip, in this case, row 23, terminal strip G.

Figure 16
 

• From the schematic in Figure 5, you can see the feedback resistor R2 is connected from the opamp non-inverting pin 2 to the opamp output pin 6. Place another 1 kΩ resistor on row 15, one end of the resistor is connected to terminal strip G and the other end to terminal strip E.
• Now place a jumper wire from the IC pin 2 which is row 19, terminal strip H and to row 15, terminal strip H.
• To complete the feedback connection, place another jumper wire from row 15, terminal strip C to row 18, terminal strip C.

Figure 17
 

Connecting the NI ELVIS Instruments

The NI ELVIS Workstation provides instruments that are commonly available in a laboratory such as an oscilloscope, function generator, and multimeter. In this exercise, you will need a function generator and an oscilloscope. The NI ELVIS Function Generation has two channels, you only need one channel in this exercise. The NI ELVIS Oscilloscope has four channels, but you just need two channels in this case.

To connect signals from the NI ELVIS Workstation to the circuit, you need three passive oscilloscope probes such as one shown in  Figure 18. This probe enables you to pass signals from the circuit being tested to the instruments. You can use the type passive probe for both the oscilloscope and the function generator.

 

The probe has a BNC connector which is to connect to the instrument. On the other end, there is a ground alligator clip for grounding with your circuit. The probe usually has a spring hook, which you can attach to your circuit, freeing your hands to do other tasks. You can use a header pin to connect the ground alligator clop and probe hook. If you do not have a header pin, use a jumper wire.

Figure 19
 

1. Connect the NI ELVIS III Function Generator to the circuit.
   • Connect the probe BNC connector to the NI ELVIS III Workstation CH 1.
   • Connect the ground alligator lead to the ground node. Figure 19 shows a pin header placed in the right – rail which is the ground node. Using a header pin, you can connect the alligator clip to the node. If you do not have a header pin, you can use a jumper wire.
   • Attach a single pin header to terminal strip H, row 23 to connect the probe from the function generator.
   • Connect the probe to resistor R1 end to supply the circuit with an AC signal.

Figure 20
 

1. Connect the oscilloscope probes to read the input signal.
   • Connect another probe BNC connector to the NI ELVIS III oscilloscope CH 1.
   • Connect the probe ground lead to the ground header pin.  
   • Attach the oscilloscope probe spring hook to the same node as the function generator.

Figure 21
 

1. Connect the oscilloscope probe to read the circuit output signal
   • Connect a third probe BNC connector to the NI ELVIS oscilloscope Ch 2.  
   • Connect the probe ground lead to the header pin that was connect to the ground node.
   •  Place a single pin header in row 18, terminal strip C and attach the probe spring hook to the header pin.

Figure 22
 

Power on the NI ELVIS III workstation and the prototyping board when you are ready. Refer the oscilloscope and function generator section in the user manual to learn how to use these instruments.  Your circuit is correctly connected if the response is similar to the simulation shown in Figure 22.

Figure 23
 

Best Practices and Troubleshooting

It is essential to build your circuit carefully. As it becomes more complicated, a neatly wired circuit will help you follow and debug any problems that may arise. You can find a short list of the best practices for wiring a breadboard circuit in the Table 2.

With an understanding of how to breadboard a circuit, the next step is to practice through hands-on experiments. Only through experiments, will you be gain the electronics knowledge to be proficient. You can expand your knowledge by downloading various labs at ni.com/teach such as the ECE  Fundamental 1 and Circuit 101. There are also many controls and measurement labs that are the building blocks for many complex systems.

 

The Problem you may Face	Recommendation	Image
You need jumper wires of different lengths.	Purchase a wire kit. The wires are cut to different lengths ranging from 0.1” to 4.0,”.  Both ends are stripped and bent 90 degrees for easy placement.  This kit will save you lab time and help wire the circuit neatly.
How to differentiate between different types of signals.	There are competing wire color code standards, for example, in automotive a black wire is for ground while household wiring uses green. Create your own color code and stick with it to help you differentiate between the different type of signals.	In electronics, use these colors for the power signals Red = Vcc Blue = -Vcc Green = ground Other signals = You decide
Complex circuits have too many connections.	Use as few jumper wires as possible. In this example, you can see the resistors are connected directly to the transistor and the power rails without using any jumper wires.
Long component leads cause short circuits.	Cut your component leads when possible. The image shows the leads are very close to each other, as you make a connection or take a measurement, it is easy to touch a component and cause a short accidentally.
You get confused with the IC pins number.	Once you placed a component on the breadboard, try not to move it too much. Attach a jumper wire or a header pin to the measuring probe and connect it to the same terminal strip node as where you want to take the measurement.
You cannot connect the component to the breadboard.	Some components are not designed for breadboarding, the leads are either too large or small, and sometimes, they do not have leads at all. To get around this, you can solder a breakable pin header to the component.
Your circuit is producing a lot of noise.	If your circuit is noisy, adding a couple of bypass capacitors across the DC voltage and ground rails may help. Use a 10 uF to 100 uF electrolytic capacitor and a 0.1 uF to 1 uF ceramic.
Your design is operating at a high frequency.	Your circuit operating frequency should be below 10 MHz. The breadboard adjacent metal strip causes high parasitic capacitance which will affect the circuit behavior. Use a solder-able board or create a custom printed circuit board (PCB) high-frequency circuits.
You circuit requires high voltage and current.	When the DC voltage to the circuit is 5 V, the maximum current should not exceed 1 A. For circuits using 15 V, the current should not exceed 0.33 A. You should use a solderable board or create a custom PCB if your circuit exceeds these voltages and current.
You need to replace the breadboards.	If a breadboard gets damage through regular usage, or if you want to connect a different board with a pre-built circuit, remove the screws from the bottom side and then screw on your board.

Next Steps

With an understanding of how to breadboard a circuit, the next step is to practice through hands-on experiments. Only through experiments will you be gain the electronics knowledge to be proficient. You can expand your knowledge by downloading labs.