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2017

Our "Power Up Your Bench Contest" Week #6 winner is Jon Snowman.

 

Here is Jon's story:

 

Background

I’m an engineer who was inspired at high school to learn electronics, and I have continued it as a hobby ever since. I am therefore immensely passionate about helping schoolchildren become as engaged and excited about science, technology, engineering and maths (STEM) subjects as I am, and to encourage them to take them up at university and in their future careers.

 

Introduction

Engaging schoolchildren with STEM subjects is considered difficult, since they can appear too academic with too few practical elements and demonstrations. To address this, I began designing and building VertigoIMU - a compact inertial and GPS datalogger which gives physics students previously impossible insight into physical systems. From the ground up, I have captured the schematic, designed the PCB and fabricated prototypes to be tested by the school.

 

VertigoIMU comprises a 9 degree of freedom IMU (3 axes of each of acceleration, gyroscope and compass), a high precision 10Hz GPS unit, barometric pressure, humidity and temperature. Data is logged to a microSD card for analysis.

 

 

Some examples of where we have successfully deployed VertigoIMU:

• On a rotating bicycle wheel to demonstrate the equations of circular motion such as centripetal acceleration (a = w^2 x r).

• On the GreenPower competition vehicle – an electric vehicle built by the students – to examine the lateral forces on the wheels to inform decisions about tyres. A plot of acceleration whilst being driven in a circle is shown below.

 

 

 

Next Steps

VertigoIMU prototypes are being tested at the school with great success. However, the principal complaint is that battery life is not long enough. Since the GPS must maintain a lock before datalogging commences, and between datalogging runs, an optimised ‘standby’ mode is required, in which the GPS retains lock and all sensors are initialised and ready.

 

Longer battery life is essential so that students can capture exciting data with VertigoIMU, especially applications in which the unit must be powered up and achieve GPS lock for a long period before datalogging commences. Some examples include:

• Roller coasters – the students are planning a visit to a local theme park

• Flight analysis – capturing the angle of attack of a BASE jumper

 

 

How the E36312A would help

This power optimisation would benefit hugely from an E36312A power supply, as I am currently using lithium polymer batteries only. The main reasons are:

 

1. High precision (<20mA) current readback mode. This would allow me to quantify and optimise the standby power consumption. This is not possible with standard bench power supplies as they typically have current precisions of around 10mA.

 

2. Overvoltage protection (OVP) and overcurrent protection (OCP). Short circuiting or over-charging/discharging of lithium batteries can be dangerous. The safe OCP/OVP modes of the E36312A would enable safer working in my home lab.

 

3. Programmable. This would permit me to simulate the discharge curve of a battery to understand details such as the total run time of the device and calibrate the battery gauge.

 

4. Multiple channels. This would accelerate develop

 

 

Congratulations Jon.  We are sending you our branding new E36312A!

 

Don't miss out.  Submit your entries now to win our brand new E36312A Triple Output DC Power Supply!

 

Go to www.keysight.com/find/PowerUpYourBench for more details. #PowerUpYourBench

Our "Power Up Your Bench Contest" Week #5 winner is Rafael Souza. See a video of his story here

Congratulations Rafael.  We are sending you our branding new E36312A!

 

Don't miss out.  Submit your entries now to win our brand new E36312A Triple Output DC Power Supply!

 

Go to www.keysight.com/find/PowerUpYourBench for more details. #PowerUpYourBench

Our "Power Up Your Bench Contest" Week #4 winner is Martin Glunz from Germany

 

Here is Martin's story...

 

1. Purpose of this document Entry to Keysight

"Power Up Your Bench” contest

 

2. Who am I

My name is Martin Glunz, a professional electronics engineer living in Germany. Not only I’m working for a company that is making industrial electronics as a R&D engineer, I’m doing some engineering at home. One of my goals is to reduce my home’s standby power consumption. I’ve done some research within this topic in the past, one of my projects was a “zero standby power” supply for the doorbell installation, done in a quite unusal way using the standard off-the-shelf doorbell transformer.

 

3. What do I want to achieve with this power supply

That’s quite easy to say: Testing the power consumption and efficiency of my circuits to save more energy. This power supply has a quite accurate voltage and current readback according to the data sheet, so this saves me the usage of two multimeters in the first place. Using a standard bench supply, there’s always the necessity to use external precision meters if one needs accurate results. My main strategy to save power is to use a intermediate DC bus (running at 19V DC) to provide power to the lot of standby boxes (like internet router, NAS box, ...). Those require various supply voltages from 5V DC to 15V DC. I’m currently using a variety of home made DC/DC converters to convert the 19V DC bus to the required voltages. Since the 19V DC bus must be supplied from the mains power, there’s a centralized power supply unit using redundant sources. To achieve my main goal, the efficiency of the involved power supplies (mains power to 19V DC, 19V DC to whatever is required) is very important to know and to be able to optimize. Your typical wall wart or power brick supply (from mains to 5V / 12V DC) in the low watts range (2W ... 20W) has still a not so good efficiency, even regarding the latest energy star regulations. So it is possible to achieve better total efficiency using the 19V DC bus approach. I’m using comercially available 19V DC supplies with good effiency here, but I’m building my own DC/DC converters to provide the local lower voltages. To achieve better total efficiency than the standard off-line power supply, these must have efficiency better than 95%. Evaluating the efficiency of such a DC/DC converter isn’t a simple task if one needs accurate results. Moreover, variation of input voltage and output load have influence on the efficiency, and the DC/DC circuit must be optimized for the typical load.

 

4. Where does this supply help me here

 

4.1. Power consumption of devices All of the devices I plan to optimize fall into the available output power range of the E36312A supply. Typically the range is from 1W at 5V DC to 20W at 12V DC. The accurate voltage and current readback together with the logging and exporting capabilities will be a great help to find out the typical power supply requirements of my devices. The supply promises to provide an easy way to make measurement of consumed DC power over time.

 

4.2. Efficiency of my converters Second, after knowing the power requirement of a device, I can go for the optimization of the DC/DC converter circuit. Doing so requires a precise measurement of input and output power of the converter, and taking measurements at varying input voltage and load conditions.

 

4.2.1. Input power measurement done by the supply The E36312A supply eases the task of measuring the input power to the DC/DC by using the precise readback, remote sensing and logging. 

 

4.2.2. Input voltage variation done by the supply An additional useful feature is the sequencing / ramping capability: This will be used to semiautomatically measure input power over input voltage at constant load.

 

4.2.3. Save a voltmeter In case one output channel provides enough power for the DC/DC converter, a second channel would be used to read back the output voltage of the DC/DC, with current limit set to zero (or a near zero voltage). Now one can read back the output voltage of the DC/DC using one channel of the power supply, only one additional amp meter will be required to read the DC/DC output current and finally calculate the efficiency.

 

4.2.4. Output load variation done by the supply Imagine now, three of four measurements are done by the bench power supply unit at constant DC/DC output load, and only one measurement left: efficiency over load variation. If one uses a constant current sink or a simple power resistor as the load to the DC/DC converter, and has the DC/DC converters output connected to the bench power supply to read back the output voltage, one could also supply some current (in CC mode) from the bench power supply into the load. This reduces the current drawn from the DC/DC output by the amount supplied from the bench supply. Now it is possible to evaluate (and semi-automate by using the remote control capabilities) the efficiency of my (or anyone elses) DC/DC converters by using just three components: The E36312A bench power suppy, a precise ampmeter and a suitable load resistor / current sink.

 

Congratulations Martin.  We are sending you our branding new E36312A!

 

Don't miss out.  Submit your entries now to win our brand new E36312A Triple Output DC Power Supply!

 

Go to www.keysight.com/find/PowerUpYourBench for more details. #PowerUpYourBench

Our "Power Up Your Bench Contest" Week #3 winner is John Hubert.

 

Here is John's story:

I work for a RF transmitter company called Nautel Ltd., my time is spent doing customer service testing and repairing of circuit boards. I personally feel the image included says a lot but I can say that this power supply would go a long way to improving my bench space. Since I work with RF many of our systems require multiple power supplies of different voltage levels. Most of these boards are very sensitive to voltage noise as they create reference voltages which cause me untold grief with some of these poorly regulated noisy supplies. The data logging features would greatly increase the information available to help me troubleshoot some issues. I also find myself having to simulate fault conditions and inputs; the sequencing and list features would greatly improve my ability to quickly test boards with complex inputs, as manually adjusting voltages usually cause timing problems. I have been trying to get my department head to purchase some of these units and I feel if I could show the company the quality of life and performance improvements built into your device we might be able to justify purchasing new equipment. A while ago we acquired an EXA spectrum analyzer 9010B and it has been a rock solid piece of equipment and a joy to use, it has become the favorite to use by many my fellow co-workers. I thank you for your time and consideration. 

 

Congratulations John.  We are sending you our branding new E36312A!

 

Don't miss out.  Submit your entries now to win our brand new E36312A Triple Output DC Power Supply!

There may be times when you need when more current than your DC bench power supply can provide. In these situations, there are traditionally two ways to go. You could add another similar power supply and parallel the two outputs together for higher power. You could also find a totally different power supply thats rated for enough power to satisfy your testing needs. Both methods require the hassle of searching for another power supply unit to meet the requirements of the test. An ideal solution would be a power supply which allows you to get that higher power within the capabilities of the same box.

Which is why you may be interested to meet the new E36312A and E36313A bench power supplies from Keysight Technologies. You can use the built-in auto-parallel mode available in the new E36312A and E36313A bench power supplies to get double the power than you would otherwise get from a single output eliminating the hassle of looking for a different power supply all together.

 

What enables this is a feature called auto-parallel mode. Auto-parallel mode uses built-in relays to combine channels 2 and 3 into a single higher current DC output channel rated for 25V and 4A. The readback system measures as a single channel too!

 

You can enable auto-parallel in two easy steps:

Step 1: Press the Output Settings button

Step 2: Press the Mode Parallel button

 

Auto-parallel front panel output connections are shown on the large graphics display. In figure 1, Channel 2 (highlighted in green) is connected to the load. The display shows that Channel 2 is now rated for 25V and 4A, while the output connectors on Channel 3 (highlighted in blue) are disabled.

 

 

 

Figure 1. Setting up auto-parallel mode.

 

A 4-wire operation can be easily configured using the Channel 2 rear panel output connector.  Note that 4-wire, or remote sensing, improves the voltage regulation at the load by monitoring the voltage at the load rather than at the output terminals. This automatically compensates for the voltage drop in the load leads, which is especially useful for CV operation with load impedance that varies or has significant lead resistance. Activate 4-wire remote voltage sensing by pressing Source Settings > Sense 4w buttons.

 

The E36300 series bench power supplies have a large, crisp display that lets you see all three output channels at the same time. By toggling the meter key button, you can drill down for more detailed information on each channel. The channels and the display are color coded so you can easily track each channel.

 

By selecting Channel 2 (highlighted in green) and toggling the meter key button, you will see more detail on Channel 2 settings and measurements.

 

In figure 2, the power supply was set for 12V, and the current limit default is set to 4A. The power supply read back (measurement system) is displaying, 12.000V, 3.452A, and 41.420 W.  You will notice that Channel 3 (dark blue color) is now blanked out and showing that it is in connected in parallel with Channel 2.


Figure 2. Auto parallel mode example.

 

You can enter or change the voltage and current limit settings by.

  1. Using the front panel voltage knob. The output voltage will change when the knob is turned. You can easily see this on the display.
  2. Using the numeric entry field in the meter display, if you know the exact voltage value that you want. Use the navigation keys to select the field (it will be highlighted) and use the numeric entry keys and enter the value.
  3. Pressing the Source Settings key and using the navigation keys to highlight the voltage field. Enter the voltage value using the numeric keys. You can use the voltage knob to adjust the value in the voltage field as well.

 

We hope this helps you get higher current capability on demand, using auto-parallel mode. For other tips, read our application note Speed up Your Test with an Upgraded Bench Power Supply.