Changes

   |Has make=BK Precision

   |Has make=BK Precision

   |Has make=Teletronix

   |Has make=Teletronix

   |Has model=2831 4 1/2 Digital Multimeter

   |Has model=1651A DC Power Supply

  |Has model=1670A DC Power Supply

   |Has model=4017A Function Generator

   |Has model=4017A Function Generator

   |Has model=TDS 2024 Oscilloscope

   |Has model=TDS 2024 Oscilloscope

   |Has name={{PAGENAME}}

   |Has name={{PAGENAME}}

   |Is located in facility=Tool Room

   |Is located in facility=Tool Room

   |Is used in domain=Electronics

   |Is used in domain=Electronics

   |Has function=Measurement

   |Has function=Measurement

   |Has icon=File:Electronics Workstation.png

   |Has icon=File:Electronics Workstation 2.png

   |Has icondesc=Multimeter Icon

   |Has icondesc=Oscilloscope graphic

   |Has image=File:Electronics Workstation.png

   |Has image=File:Electronics Workstation 2.png

   |Has imagedesc=Electronics Workstation

   |Has imagedesc=Electronics Workstation

   |Has description=Standard electronics measurement and signal generation equipment.

   |Has description=Standard electronics measurement and signal generation equipment.

==DC Power Supply==

==DC Power Supply==

 

The most basic function of a DC power supply is to provide a constant voltage to a device. “DC” stands for direct current; “AC” stands for alternating current. A 9V battery is an example of a DC voltage, and it will hold a constant 9 volts (at least until the battery starts to die). A 120V wall outlet is an example of an AC voltage, and it will fluctuate up and down from 120V to -120V and back to 120V over a set period of time. A DC power supply converts the alternating current from a wall outlet to a steady direct current through a system of transformers and filtering circuitry. We have a couple different models of DC power supplies in the Maker Hub.

The most basic function of a DC power supply is to provide a constant voltage to a device. “DC” stands for direct current; “AC” stands for alternating current. A 9V battery is an example of a DC voltage, and it will hold a constant 9 volts (at least until the battery starts to die). A 120V wall outlet is an example of an AC voltage, and it will fluctuate up and down from 120V to -120V and back to 120V over a set period of time. A DC power supply converts the alternating current from a wall outlet to a steady direct current through a system of transformers and filtering circuitry. We have a couple different models of DC power supplies in the Maker Hub.

==Function Generator==

==Function Generator==

 

A signal generator creates periodic waveforms; it allows the user to manipulate an electrical signal’s amplitude, duty cycle, offset, and frequency over a wide range of values. This signal generator can produce sine, square, triangle, ramp, and digital pulse waveforms. The manual for this signal generator is fairly well-written, so I will only highlight a few excerpts here. I would encourage you to read the manual for complete operating instructions.

A function generator creates AC periodic waveforms; it allows the user to manipulate an electrical signal’s amplitude, duty cycle, offset, and frequency over a wide range of values. This function generator can produce sine, square, triangle, ramp/sawtooth, and digital pulse waveforms. The manual for this function generator is fairly well-written, so I will only highlight a few excerpts here. I would encourage you to read the manual for complete operating instructions.

===Controls===

===Controls===

 

There are eight range switches that select output frequencies from <1Hz to 10MHz. The coarse frequency knob adjusts the frequency within a range from 10% of the maximum to the maximum. For example, if the 100kHz range is selected, the output frequency can be adjusted from 10kHz to 100kHz. The duty cycle, CMOS level, DC offset, and -20dB functions are only active if their corresponding switches are pressed in. The duty cycle knob alters the symmetry of the waveform through skewing or changing the ratio of “on” time versus “off” time. The DC offset changes the mean amplitude of the waveform. Reference the manual for information on more advanced capabilities such as the sweep functions, TTL/CMOS, and voltage-controlled generation.

There are eight range switches that select output frequencies from <1Hz to 10MHz. The coarse frequency knob adjusts the frequency within a range from 10%-of-the-maximum to the maximum. For example, if the 100kHz range is selected, the output frequency can be adjusted from 10kHz to 100kHz. The duty cycle, CMOS level, DC offset, and -20dB functions are only active if their corresponding switches are pressed in. The duty cycle knob alters the symmetry of the waveform through skewing or changing the ratio of “on” time versus “off” time. The DC offset changes the mean amplitude of the waveform. Reference the manual for information on more advanced capabilities such as the sweep functions, TTL/CMOS, and voltage-controlled generation.

The best way to “see” the output of a function generator is to use an oscilloscope. An oscilloscope will show you a graphical representation of the signal, and allow you to understand the effects of the waveform shape, frequency range switches, coarse/fine adjustment, duty cycle, DC offset, etc.

The best way to “see” the output of a function generator is to use an oscilloscope. An oscilloscope will show you a graphical representation of the signal, and allow you to understand the effects of the waveform shape, frequency range switches, coarse/fine adjustment, duty cycle, DC offset, etc.

A signal generator is designed as a precision device that can produce very specific waveforms; it is not designed as a powering device capable of generating large voltages or currents from its output. This is one of the reasons why a signal generator is commonly used alongside a DC power supply. A common benchtop DC power supply excels at providing a precise DC voltage at a moderate current (usually less than 10A), but it cannot produce waveforms on its own. If you want to produce a waveform with moderate voltage/current, one great method is to design an amplifier circuit. An amplifier circuit commonly uses a transistor (or series of transistors) to turn small low-power signals into larger moderate-power signals. The signal generator provides the small signal to the input of the transistor, which modulates the DC voltage at the output of the transistor to create a larger moderate-power signal.

A function generator is designed as a precision device that can produce very specific waveforms; it is not designed as a powering device capable of generating large voltages or currents from its output. This is one of the reasons why a function generator is commonly used alongside a DC power supply. A common benchtop DC power supply excels at providing a precise DC voltage at a moderate current (usually less than 10A), but it cannot produce waveforms on its own. If you want to produce a waveform with moderate voltage/current, one great method is to design an amplifier circuit. An amplifier circuit commonly uses a transistor (or series of transistors) to turn small low-power signals into larger moderate-power signals. The function generator provides the small signal to the input of the transistor, which modulates the DC voltage at the output of the transistor to create a larger moderate-power signal.

===Impedance===

===Impedance===

Next to the output terminal on the signal generator, it says “50Ω.” This means that the output impedance of the signal generator is 50Ω, which is considered a low output impedance. Impedance is similar in concept to resistance, but it includes additional complex elements that describe frequency-dependent resistance in AC circuits. A low impedance output offers a couple of options: you can design the input of your circuit for impedance matching (maximum power transfer to the load) or impedance bridging (maximum voltage signal to the load). In this case, impedance matching would mean that the input impedance of your circuit is also at 50Ω. For impedance bridging, the input impedance of your circuit would be much much greater than 50Ω (on the order of kΩ or MΩ). The circuit you’ll be testing in this certification is designed for impedance bridging with the signal generator.

Next to the output terminal on the function generator, it says “50Ω.” This means that the output impedance of the function generator is 50Ω, which is considered a low output impedance. Impedance is similar in concept to resistance, but it includes additional complex elements that describe a frequency-dependent resistance in AC circuits. A low impedance output offers a couple of options: you can design the input of your circuit for impedance matching (maximum power transfer to the load) or impedance bridging (maximum voltage signal to the load). In this case, impedance matching would mean that the input impedance of your circuit is also at 50Ω. For impedance bridging, the input impedance of your circuit would be much much greater than 50Ω (on the order of kΩ or MΩ). The circuit you’ll be testing in this certification is designed for impedance bridging with the function generator.

Why mention all this business about impedance? This will help you know what to expect from the signal generator and how to design circuits better. In the manual, it states, “Remember that the output signal swing of the generator is limited to ±10V open circuited or ±5V into 50Ω, and applies to the combined peak-to-peak signal and DC offset. Clipping occurs slightly above these levels.” This means that if the signal generator is impedance bridged with your circuit, don’t expect to generate signals outside of a ±10V range. If the signal generator is impedance matched with your circuit, don’t expect to generate signals outside of a ±5V range. This includes the DC offset in both cases. If your input impedance falls anywhere between 50 Ω and an open circuit (∞Ω), the maximum signal you can get from the signal generator will fall between ±5V and ±10V, respectively. Unless you really know what you are doing, do not use the signal generator on circuits that have an input impedance of less than 50 Ω. Similarly, do not choose an injection point in your circuit for the signal generator that has a DC voltage higher than what can be achieved with the DC offset knob. Only choose injection points where the DC voltage can be matched with the DC offset knob; otherwise, this can cause internal damage to the signal generator.

Why mention all this business about impedance? This will help you know what to expect from the function generator and how to design circuits better. In the manual, it states, “Remember that the output signal swing of the generator is limited to ±10V open circuited or ±5V into 50Ω, and applies to the combined peak-to-peak signal and DC offset. Clipping occurs slightly above these levels.” This means that if the function generator is impedance bridged with your circuit, don’t expect to generate signals outside of a ±10V range. If the function generator is impedance matched with your circuit, don’t expect to generate signals outside of a ±5V range. This includes the DC offset in both cases. If your input impedance falls anywhere between 50Ω and an open circuit (∞Ω), the maximum signal you can get from the function generator will fall between ±5V and ±10V, respectively. Unless you really know what you are doing, do not use the function generator on circuits that have an input impedance of less than 50 Ω. Similarly, do not choose an injection point in your circuit for the function generator that has a DC voltage higher than what can be achieved with the DC offset knob. Only choose injection points where the DC voltage can be matched with the DC offset knob; otherwise, this can cause internal damage to the function generator.

===Using a Function Generator===

===Using a Function Generator===

You can test the function generator by connecting it directly to the leads of an oscilloscope. Just remember that the function generator will be impedance bridged with the oscilloscope, so you may observe a slight reduction in your signal’s amplitude after connecting the function generator to your circuit. After checking your circuit, connect the leads from the function generator to the circuit before turning on the power. On our particular model of function generator, the output is always on, so keep that in mind as you use it.

You can test the function generator by connecting it directly to an oscilloscope probe. Just remember that the function generator will be impedance bridged with the oscilloscope, so you may observe a slight reduction in your signal’s amplitude after connecting the function generator to your circuit. After checking your circuit, connect the leads from the function generator to the circuit before turning on the power. On our particular model of function generator, the output is always on, so keep that in mind as you use it.

Don’t be afraid to spend time with your function generator; its primary love language is definitely quality time.

Don’t be afraid to spend time with your function generator; its primary love language is definitely quality time.

One of the first things we need to understand about the oscilloscope is what it’s actually showing on the display screen. The display is set up like a standard Cartesian coordinate system. (you know, a graph...){{#evu:https://www.youtube.com/watch?v=sIlNIVXpIns|graph}}

One of the first things we need to understand about the oscilloscope is what it’s actually showing on the display screen. The display is set up like a standard Cartesian coordinate system. (you know, a graph...){{#evu:https://www.youtube.com/watch?v=sIlNIVXpIns|graph}}

The units of the graph tell us a lot about what we are looking at. The y-axis is voltage, and the x-axis is time. So, an oscilloscope will show—in real time—how a voltage signal is changing over time. One key skill we need to learn when using the oscilloscope is to manipulate the scales of the x-axis and y-axis so that you can see the voltage signal clearly and meaningfully on the oscilloscope’s display.

The units of the graph tell us a lot about what we are looking at. The y-axis is voltage, and the x-axis is time. So, an oscilloscope will show—in real time—how a voltage signal is changing over time. One key skill we need to learn when using the oscilloscope is to manipulate the scales of the x-axis and y-axis so that you can see the voltage signal clearly and meaningfully on the oscilloscope’s display.

There are 4 BNC jacks are on the bottom row of the oscilloscope’s control panel. Each one corresponds to channels 1, 2, 3, and 4. This is where you will plug in the probes that will measure various voltage signals in your circuit. Let’s discuss the knobs and buttons under the VERTICAL section of the control panel. For CH 1, the POSITION knob will move the signal on the display screen of the oscilloscope up and down the y-axis. This is handy when there is a DC voltage offset applied to the AC signal. The VOLTS/DIVISION knob will stretch or shrink the y-axis so that you can see the waveform’s amplitude properly. If the peaks or troughs of the waveform are hitting the top and/or bottom of the display screen, use the VOLTS/DIVISION knob to shrink the y-axis so that the full waveform can be seen. The CH 1 MENU button allows you to set up the probe properties and measurement displays for channel 1. The MATH MENU button allows you to perform operations between channels such as subtracting CH 2 from CH 1.

There are 4 BNC jacks are on the bottom row of the oscilloscope’s control panel. Each one corresponds to channels 1, 2, 3, and 4. This is where you will plug in the probes that will measure various voltage signals in your circuit. Let’s discuss the knobs and buttons under the VERTICAL section of the control panel. For CH 1, the POSITION knob will move the signal on the display screen of the oscilloscope up and down the y-axis. This is handy when there is a DC voltage offset applied to the AC signal. The VOLTS/DIVISION knob will stretch or shrink the y-axis so that you can see the waveform’s amplitude properly. If the peaks or troughs of the waveform are hitting the top and/or bottom of the display screen, use the VOLTS/DIVISION knob to shrink the y-axis so that the full waveform can be seen. The CH 1 MENU button allows you to set up the probe properties and measurement displays for channel 1. The MATH MENU button allows you to perform operations between channels such as subtracting CH 2 from CH 1.

The HORIZONTAL section of the control panel let’s you manipulate the x-axis of the display screen. The POSITION knob acts as time offset. In most cases, this can be set to zero, but you’ll notice that you can shift the waveform left and right by turning this knob. The SECONDS/DIVISION knob will stretch or shrink the x-axis so that you can see the waveform’s frequency/period properly. If you’re ever wondering why your 100kHz sine wave looks like a solid fuzzy block on the display screen, you need to zoom way in with the SECONDS/DIVISION knob to see the individual peaks and troughs. You might do some basic math to know where you need to set the knob (sounds crazy, right???). 100kHz is the frequency… that means the period of the waveform is 10μS. If I set the SECONDS/DIVISION knob to 10μS per division, then I should see roughly 5 peaks and 5 troughs of the waveform on the display screen because there are 5 dashed grid lines (4 plus the y-axis) across the screen that mark the divisions.

The HORIZONTAL section of the control panel let’s you manipulate the x-axis of the display screen. The POSITION knob acts as time offset. In most cases, this can be set to zero, but you’ll notice that you can shift the waveform left and right by turning this knob. The SECONDS/DIVISION knob will stretch or shrink the x-axis so that you can see the waveform’s frequency/period properly. If you’re ever wondering why your 100kHz sine wave looks like a solid fuzzy block on the display screen, you need to zoom way in with the SECONDS/DIVISION knob to see the individual peaks and troughs. You might do some basic math to know where you need to set the knob (sounds crazy, right???). 100kHz is the frequency… that means the period of the waveform is 10μS. If I set the SECONDS/DIVISION knob to 10μS per division, then I should see roughly 10 peaks and 10 troughs of the waveform on the display screen because there are 9 vertical dashed grid lines (8 plus the y-axis) across the screen that mark the divisions.

The trigger on an oscilloscope is an important part of properly displaying a waveform. The trigger determines when the oscilloscope starts to acquire data. When a trigger is set up properly, the oscilloscope converts unstable displays or blank screens into meaningful waveforms. Of the types of triggers available on this oscilloscope, most waveforms can be captured using the edge mode. In the TRIGGER section on the control panel of the oscilloscope, you’ll see a LEVEL knob. When you turn the LEVEL knob, you should see a little pointer moving up and down the side of the display screen (in the direction of the y-axis). Generally, the trigger level can be set to approximately the middle of the waveform for good results.

The trigger on an oscilloscope is an important part of properly displaying a waveform. The trigger determines when the oscilloscope starts to acquire data. When a trigger is set up properly, the oscilloscope converts unstable displays or blank screens into meaningful waveforms. Of the types of triggers available on this oscilloscope, most waveforms can be captured using the edge mode. In the TRIGGER section on the control panel of the oscilloscope, you’ll see a LEVEL knob. When you turn the LEVEL knob, you should see a little pointer moving up and down the side of the display screen (in the direction of the y-axis). Generally, the trigger level can be set to approximately the middle of the waveform for good results.

==Digital Multimeter==

==Digital Multimeter==

 

A digital multimeter can measure a host of electrical properties including DC voltage and current, AC voltage and current, resistance, continuity, frequency, period, dB, dBm, True RMS AC+DC, and diode testing.

A digital multimeter can measure a host of electrical properties including DC voltage and current, AC voltage and current, resistance, continuity, frequency, period, dB, dBm, True RMS AC+DC, and diode testing.

The red terminal labelled with "V Ω Diode Hz Continuity" is used for all voltage, resistance, diode, frequency/period, and continuity functions described above (including the voltage measurement for AC+DC).

The red terminal labelled with "V Ω Diode Hz Continuity" is used for all voltage, resistance, diode, frequency/period, and continuity functions described above (including the voltage measurement for AC+DC).

The two red terminals labelled 20A and 500mA MAX are used for all current functions described above (including the current measurement for AC+DC). Basically, the 20A terminal is for higher currents, and the 500mA MAX terminal is for low currents. If you're unsure of how much current you'll measure, always start with the 20A terminal first. Then, only switch to the low current terminal if the amperage is well below 500mA.

The two red terminals labelled 20A and 500mA MAX are used for all current functions described above (including the current measurement for AC+DC). Basically, the 20A terminal is for higher currents, and the 500mA MAX terminal is for low currents. If you're unsure of how much current you'll measure, always start with the 20A terminal first. Only then, switch to the low current terminal if the amperage is well below 500mA. Keep in mind that the 20A terminal will not give any readings in the "auto-detect" mode. You must set the range manually with the "Level/Value" up and down arrows.

====How To Measure With The Leads====

====How To Measure With The Leads====

Ground (sometimes called neutral or earth) is usually at 0V. Ground acts a reference point for most electronic circuits. It is good practice to connect all ground references to a common point; inversely, it is a very bad practice to leave floating ground points in your circuit. If you are using multiple benchtop instruments simultaneously such as a DC power supply, signal generator, oscilloscope, and digital multimeter, you should create a common ground between all instruments (and your circuit too) to ensure that you get accurate measurements and don’t have strange circuit behavior.

Ground (sometimes called neutral or earth) is usually at 0V. Ground acts a reference point for most electronic circuits. It is good practice to connect all ground references to a common point; inversely, it is a very bad practice to leave floating ground points in your circuit. If you are using multiple benchtop instruments simultaneously such as a DC power supply, signal generator, oscilloscope, and digital multimeter, you should create a common ground between all instruments (and your circuit too) to ensure that you get accurate measurements and don’t have strange circuit behavior.

==Documentation==

==Documentation==

====User Manuals====

====User Manuals====

[[Media:4017A Function Generator Manual.pdf|4017A Function Generator Manual]]

 

[[Media:4017A Function Generator Manual.pdf|4017A Function Generator User Manual]]

[[Media:TDS 2024 Oscilloscope.pdf|TDS 2024 Oscilloscope Manual]]

[[Media:TDS 2024 Oscilloscope.pdf|TDS 2024 Oscilloscope User Manual]]

[[Media:2831E Digital Multimeter Manual.pdf|2831E Digital Multimeter Manual]]

[[Media:2831E Digital Multimeter Manual.pdf|2831E Digital Multimeter User Manual]]

==Safety==

==Safety==

* No "rat's nest" wiring. Minimize the amount of bare, exposed wire in your circuit--especially if it is loose and can move around easily. This is an electrocution and short circuit risk.

* No "rat's nest" wiring. Minimize the amount of bare, exposed wire in your circuit--especially if it is loose and can move around easily. This is an electrocution and short circuit risk.

* If you somehow manage to start an electrical fire, use a fire extinguisher to put it out. NEVER use water to put out an electrical fire. Baking soda also works... should you happen to have it handy.

* If you somehow manage to start an electrical fire, use a fire extinguisher to put it out. NEVER use water to put out an electrical fire. Baking soda also works... should you happen to have it handy.