Збирач потоків

Стажування в компанії Ajax Systems: для чого, для кого і з якими перспективами Інформація КП чт, 05/01/2025 - 08:09

Got tired of manually turning on my laptop cooling pad(IETS600). So I used a leftover Arduino to tap into the PWM pin of the fan motor. Communicate via USB Serial from a c# program that monitors which app is open, and if its a game, will send the instruction to the Arduino to turn on the PWM pin at whatever speed I want :) submitted by /u/SolitaryMassacre [link] [comments]

Machine intelligence enables a new era of productivity and is becoming an integral part of our lives and societies across many disciplines and functions. Machine intelligence relies on computing platforms that execute code, decipher data, and learn from trillions of data points in fractions of a second. The computing hardware for machine intelligence needs to be fast, extremely reliable, and powerful. Designers must combine solid design practices with self-diagnostics and continuous monitoring schemes to prevent or manage potential faults such as data corruption or communication errors in the system.

An essential element in such monitoring systems is the supervision and monitoring of power rails throughout the system. In this article, I’ll examine and describe some of the best practices for designing supply and processor rail-monitoring solutions in enterprise applications.

Understanding power architectures

Enterprise computing relies upon a complex power architecture that delivers energy from AC sources to every point of load in the system. Figure 1 is a high-level illustration of elements in a server rack.

Figure 1 High-level server rack diagram with distributed battery backup units (BBUs) and power supply units (PSUs) connected to a busbar that then distributes AC power thought to the rack. Source: Texas Instruments

A high-efficiency—typically >91% for a titanium-grade design—PSU converts and then distributes AC power (208 V or 240 V) to 48 V throughout the rack. The power distribution board (PDB) then converts DC power to various voltages, typically 12 V, 5 V, and 3.3 V, for feeding to subsystems including the motherboard, storage, network interface cards (NICs), and switches, and system cooling. Each of these subsystems, in turn, has its own locally managed power architecture. A battery backup unit (BBU) maintains system power during any AC line disruptions.

Designing for durability

Each subsystem requires a reliable power design and monitoring. Let’s examine some of these subsystems further.

The PSU

PSUs have several types of monitoring to ensure reliable operation and delivery. They monitor the AC mains’ output voltage while also detecting internal temperature, over- and under-voltage conditions, and short circuits.

Server designs also require N+1 redundancy: “N” represents the minimum number of necessary PSUs to meet server power needs. An additional PSU (“+1”) is available if one of the other PSUs encounters a temporary or permanent fault or failure.

The PDB

As mentioned earlier, the PDB converts a 48-V input to several DC rails, including 12 V, 5 V, and 3.3 V. Although comparators with simple shunt references can be used to monitor each of these rails for overvoltage and undervoltage conditions, modern-day voltage supervisors offer a small footprint and ease of design and provide additional benefits such as hysteresis and input-sense delay for noise immunity, an adjustable output delay to avoid false triggers during power up, and higher accuracy for the highest detection reliability.

Many new voltage supervisors, such as the Texas Instruments (TI) TPS3760, are rated for voltages as high as 70 V, and can monitor 48 V and other bus voltages directly without needing a low-dropout regulator or dedicated power rail. In addition to real-time supervision, advanced monitoring integrated circuits can provide telemetry data on the most vital rail voltages to enable predictive maintenance and historical fault analysis, significantly reducing system downtime.

Another design consideration is early power failure detection. These circuits monitor specific supply rails for sudden voltage drops and alert the host or processor to take swift action in anticipation of a power loss. A high-speed and precise undervoltage supervisor performs this function. Figure 2 illustrates an example of this type of design and its timing diagram.

Figure 2 A voltage supervisor example with a timing diagram, monitoring the 0.85 to 6.0 V supply rail for sudden voltage drops to take action in the event of a power loss. Source: Texas Instruments

The motherboard

Motherboard power rails present designers with a different set of challenges, which I’ll examine in more detail in this section.

Processor rail monitoring

Modern processors are very sensitive to variations in their power supply rails. There are many reasons for this, but it is mostly because these processors operate at voltages as low as 0.7  V with reduced tolerance for voltage fluctuations and utilize features such as dynamic voltage and frequency scaling.

Consequently, the processors require high-precision window voltage supervisors. Window supervisors monitor the supply voltage for both overvoltage and undervoltage conditions. Devices targeted for these applications, such as TI’s TPS389006, have an accuracy of ±6 mV. Designers can adjust the glitch filter up to 650 ns through the I2C registers.

Another essential aspect of power-rail design is the system’s ability to maintain stability during rapid load transients. Modern processors can shift from idle to full load in microseconds, causing sharp voltage droops or overshoots if the power supply and monitoring systems are not designed with fast loop responses and the appropriate output capacitance.

Proper power-up and power-down supply sequencing is also essential for the motherboard and processor. Sequencing ensures proper system initialization—for instance, a processor may require that the memory controller be operational before executing instructions. Sequencing also prevents large inrush currents and voltage spikes during power-up. During power-down, sequencing maintains data integrity by giving memory and storage devices enough time to save data or complete operations before losing power.

Figure 3 provides a design example for the monitoring and sequencing of the supply rails.

Figure 3 Supply-rail monitoring and sequencing examples for proper system initialization. Source: Texas Instruments

Finally, managing inrush current is vital for systems with hot-swappable components to avoid tripping circuit protection or destabilizing the power bus. Hot-swap controllers equipped with integrated current limiting and fault detection ensure smooth insertion and removal without disrupting other active subsystems.

Future trends

The enterprise industry is poised to transition to a 400 VDC power-distribution system, which would increase efficiencies by eliminating redundant power-conversion stages and I²R losses and reduce copper usage and costs. Such high-voltage systems will demand even more high-powered rail monitoring, with faster fault detection and isolation, to maintain safety and system uptime. A new generation of high-voltage monitoring solutions is emerging to address the future design needs in this space.

Compelling power architectures are essential for ensuring reliable and uninterrupted operation in enterprise systems. Combining solid power-design practices with real-time monitoring and early fault detection helps prevent unexpected failures and protects critical workloads. As system complexity grows and power architectures evolve, especially with the shift toward higher voltage distribution, careful planning and rail supervision will continue playing a role in delivering safe and efficient performance.

Masoud Beheshti leads application engineering and marketing for Linear Power at Texas Instruments. He brings extensive experience in power management, having held roles in system engineering, product line management, and marketing and applications leadership. Masoud holds a bachelor’s degree in electrical engineering from Ryerson University and an MBA with concentrations in marketing and finance from Southern Methodist University.

Related Content

• Power Tips #139: How to simplify AC/DC flyback design with a self-biased converter
• Data center power meets rising energy demands amid AI boom
• Data center next generation power supply solutions for improved efficiency
• Optimize data-center power delivery architecture

 

The post Power Tips #140: Designing a data center power architecture with supply and processor rail-monitoring solutions appeared first on EDN.

I’ve been working on an article about vacuum tube triodes. Yes, they’re still being used in the manufacture of high-end audio equipment and in musical instrument amplifiers. A triode has three electrodes: a plate (in American parlance, “anode” in the UK), a control grid, and a cathode.

Figure 1 contains a typical graph of plate currents verses plate voltages for different grid voltages, with grid voltages labeled on each curve as 0, -0.5, -1. 0…-5.0. All voltages are with respect to the cathode. Pretty clear, right?

Figure 1 A typical graph of triode characteristics from a manufacturer’s datasheet.

Part of the article involves measuring triode characteristics and constructing graphs in Excel which display the measured data. Figure 2 shows the first attempt to present this graphically.

Figure 2 A simple display of the acquired data, the colors shown are defaults selected by Excel.

The data for the left-most curve was entered first; the one immediately to the right next, and so on. Excel assigns curve colors in the order shown by default. There doesn’t seem to be any order to the progression of colors that might aid in scanning through the LEGEND table on the right to find a curve’s grid-voltage name.

And some of the colors are so similar that it can be challenging to find the right association. There’s also no easy way to label the LEGEND table to indicate the type of information it contains other than adding a text box to the chart. But if you reposition the chart, the text box must be moved separately.

There must be a better way to convey this information to the reader. Suppose the colors could be changed to a more recognizable progression, such as the visible spectrum-related order of the color bands on a resistor which indicates its resistance. Furthermore, what if this reordering could be automated with a keyboard click for any chart? We’re talking Excel macros, right? We could manually make the change for one graph and record the steps as a macro. But we’d have to know how many curves a particular graph had to use such. Hmmm.

Ok, let’s instead create a macro using the subroutine “sub” feature in Excel’s built-in Visual Basic for Applications (VBA) code. The code should be easily able to handle a chart with any number of curves. Now, I’ve worked with VBA, but I’m no expert. So, when I come across a feature I need but I’m not familiar with, I have to do an online search, find a reference that I can understand, and apply and test it. Rinse and repeat. This is tedious. Is there a work-around for a time-crunched, lazy guy like me? Turns out the answer is yes: AI.

I asked one of these well-known beasts how I might automatically re-order the colors assigned to Excel chart curves. The code it returned in reply worked the first time and came with comments! I’ve made a few changes and added some comments of my own to produce the code listed in Appendix 1. Clicking to select the chart shown in Figure 2 and running this code produces the results seen in Figure 3.

Figure 3 The curve colors progress in the same order as the resistance color-code bands on resistors, and backgrounds were colored for better visibility of the yellow and white curves.

In addition to reordering the colors, the code has thickened the curves and added a background color of light grey for better visibility. All the code is commented, and the background and curve thicknesses can be easily modified. You’ll notice that there are eleven curves but only ten colors, so the -5.0-volt curve is the same color as the 0.0-volt curve; the colors automatically repeat.

But one of the features of the code is its ability to change what’s called the “dashstyle” of the curves each time the colors repeat. I believe that the code is adequately commented to allow a user to locate and modify or eliminate this behavior if desired.

Labeling the curves

I was happy with this until I looked back at the chart in Figure 1. Why refer to a legend on the side of the graph if I could put the grid-voltage curve names right next to the curves themselves? I went back to the AI engine to ask for help. This time, I got code that didn’t work the first time. But that didn’t stop me; when I described the problems I was seeing specifically, I got debugging help! Clicking to select the chart rendered in Figure 2, the Appendix 2 code produced the graph seen in Figure 4.

Figure 4 Each curve’s grid-voltage name is placed next to the end of the curve.

Maybe you’d like to combine effects by running the Appendix 1 code on Figure 4’s chart to produce that seen in Figure 5.

Figure 5 The Appendix 1 and Appendix 2 codes are run sequentially: first the code which appends the curve names near the ends of the curves, and then the code which reorders the curve colors.

There’s no longer any need for the legend box, so I manually deleted it after running the codes.

I found the two VBA programs presented in the first two Appendices to provide a simple, quick, and automatic means to enhance the readability of basic graphs in Excel. I’m keeping them in my Excel toolbox. For those unfamiliar with how to use VBA, Appendix 3 should prove helpful.

Christopher Paul has worked in various engineering positions in the communications industry for over 40 years.

Related Content

• Tell us your Tale
• What is the biggest mistake you have made as an engineer?
• Visualizing Data with Arduino
• PUT a reset in its place

APPENDIX 1

Code to specify the colors assigned to curves on a chart. Select a chart and run the macro associated with this code.

Sub ApplySpectrumColors() Dim cht As Chart, series As series, i As Integer Dim colors_ As Variant, line_type As Variant, the_weight As Variant ' Define the spectrum colors as RGB values ' (see https://www.teoalida.com/wordpress/wp-content/uploads/Excel-colors-with-RGB-values-by-Teoalida.png) colors_ = Array(RGB(32, 0, 0), RGB(160, 140, 0), RGB(255, 128, 128), RGB(255, 192, 128), RGB(255, 255, 0), RGB(0, 192, 0), _ RGB(96, 255, 255), RGB(176, 96, 255), RGB(211, 211, 211), RGB(255, 255, 255)) ' Define the line types. See https://learn.microsoft.com/en-us/office/vba/api/office.msolinedashstyle line_type = Array(msoLineSolid, msoLineLongDash, msoLineDashDot, msoLineSquareDot) ' Define line_type weights (thicknesses) the_weight = Array(3, 3, 4, 4) ' Reference the active chart On Error Resume Next Set cht = ActiveChart On Error GoTo 0 If cht Is Nothing Then MsgBox "Please select a chart before running this script.", vbExclamation Exit Sub End If ' Loop through each series and assign spectrum colors,line styles and weights i = 0 For Each series In cht.SeriesCollection series.Format.Line.ForeColor.RGB = colors_(i Mod (UBound(colors_) + 1)) series.Format.Line.DashStyle = line_type(Int(i / (UBound(colors_) + 1)) Mod (UBound(line_type) + 1)) series.Format.Line.Weight = the_weight(Int(i / (UBound(colors_) + 1)) Mod (UBound(the_weight) + 1)) i = i + 1 Next series ' Change Plot Area Background Color cht.PlotArea.Format.Fill.ForeColor.RGB = RGB(236, 236, 236) ' Change Legend Background Color cht.Legend.Format.Fill.ForeColor.RGB = RGB(236, 236, 236) MsgBox "Spectrum colors applied successfully!", vbInformation End Sub APPENDIX 2

Code to place the names of each curve next to that curve on a chart. Select a chart and run the macro associated with this code.

Sub LabelCurvesWithStyle() Dim cht As Chart, srs As series, pt As Point, i As Integer, seriesCount As Integer Dim validSeriesCount As Integer, lastValue As Variant On Error Resume Next Set cht = ActiveChart ' Get the active chart On Error GoTo 0 If cht Is Nothing Then ' If no chart is selected MsgBox "No chart is selected. Click on a chart and try again.", vbExclamation, "Error" Exit Sub End If seriesCount = cht.SeriesCollection.Count 'number of series in the chart validSeriesCount = 0 ' Loop through each series in the chart For Each srs In cht.SeriesCollection If srs.Points.Count > 0 Then i = srs.Points.Count ' Last point in the series lastValue = srs.Values(i) ' Get the last Y value ' Check if last value is numeric before labeling If IsNumeric(lastValue) And Not IsEmpty(lastValue) Then Set pt = srs.Points(i) ' Add a label pt.HasDataLabel = True pt.DataLabel.Text = srs.Name pt.DataLabel.Position = xlLabelPositionRight ' for otherlabel positions, see ' https://learn.microsoft.com/en-us/office/vba/api/Excel.XlDataLabelPosition With pt.DataLabel.Font ' Set font styling .Name = "Arial" ' Font type .Size = 10 ' Font size .Bold = True ' Make text bold .Color = RGB(255, 0, 0) ' Font color (Red) '.Italic = True ' Uncomment for italic text End With validSeriesCount = validSeriesCount + 1 Else MsgBox ("Series labeled " & srs.Name & " has non-numeric data.") End If End If Next srs If validSeriesCount < seriesCount Or validSeriesCount = 0 Then MsgBox "Non-numeric data found in at least one series. No labels applied." End If End Sub APPENDIX 3

For those unfamiliar with Excel’s VBA, this AI-generated tutorial should be helpful.

The post Clearing out the data clutter appeared first on EDN.