Tuesday, August 23, 2016

USB Oscilloscopes from Pro to Hobbyist (review by Martin Rowe EETimes):

 Martin Rowe of  EETimes reviewed PC-based oscilloscopes from 16 different companies in an article titled "USB Oscilloscopes from Pro to Hobbyist  " ()

He states that the ubiquitous USB port has given rise to an entire industry of connected test equipment. Most notably - oscilloscopes. In this article he presents products from 16 companies that make what used to be called "PC-based" oscilloscopes, defined as those that require an external computer for display and control.  It's not a comprehensive list, with just one or two models per company, generally the lowest cost and highest performance models. He provides some basic specifications and prices in a table that you can download, but there are many more specs to consider when choosing a USB oscilloscope. For example:
  • Triggers
  • Waveform memory
  • Data recording
  • Math
  • Serial bus decoding
The products are divided into five groups based on price. 

Monday, August 22, 2016

USB Type-C – why is it better?

In its latest blog entry, USB-charging supplier Cambrionix has some useful comments on the new Type-C connector:

USB Type-C is the latest connector that’s being incorporated into USB devices for charging and syncing data. It was first released in August 2014 and uses a new small 24-pin reversible-plug connector. This makes plugging in devices much easier and no more guessing which way is up!
As the adoption of USB Type-C increases its a good time to know what the latest updates are in the world of Type-C, and how it affects you:
  1. Universal cables and chargers for all of your devices! – The main original USB connectors are TypeA , TypeB , miniB and microB. The new USB Type-C should eventually replace all of these meaning a much easier and more universal way to manage your devices.
  2. Faster device charging -Type-C can support significantly faster charging if the device and charger support it, this is known as Power Delivery ( PD) – something that will be welcomed by all of us!
  3. Charge your laptop over USB – An increase in power available with USB Type-C will allow you to charge higher powered devices such as laptops with this new style connector.
  4. Faster data transfer – Type-C connectors by default support USB2 and can support the faster USB3 data transfer speeds of 10Gbps! There are two generations of USB 3 known as ‘USB 3.1 Gen1’ and ‘USB 3.1 Gen2’. Gen 1 is up to 5Gbps of data which is about 10x fast than USB 2.0 and Gen 2 is up to 10Gbps which is about 20x fast than USB 2.0.
  5. Additional data available – Type-C connectors enable remote monitoring of the device battery if the device supports it.

USB Type-C is the latest USB style connector. It’s smaller, reversible, provides faster charging, faster data transfer and gives more scope for advanced device reporting/data than its USB predecessors!
As you can see Type-C has lots of advantages for consumers – Devices will be easier to connect, charge faster, transfer data faster and provide more data and information about devices and their charging!

Type-C Cables

When buying USB Type-C cables you need to know that there are two levels of power available.
Currently you can purchase either a 3A (60W) or 5A (100W) Type-C cable so depending on the power and speed of what you need to charge or charge and sync would determine the cable to use.
It is very important to get the right cable as a low power cable could mean slower charging!
Through our testing we found of a number of poor quality USB Type-C cables which is very disappointing, so please be careful when buying any cables!

USB Type-C Chargers and the future…

The latest version of the Power Delivery (PD) specification has made marking of power supplies simpler for the end user. PD enables the device and charger to negotiate what voltage and how much current is available to use for charging.  In the original specification this could mean a charger could provide 20v at 2Amp ( 40Watts) but not provide 9v @2Amp ( 18Watts) . So the 40Watt charger wouldn’t charge a device that only needs 18Watts!  This has since been changed so a charger that is compliant with the latest PD specification will always be able to charge devices up to its power rating. If a charger is rated at 27Watts this will charge all devices that require 27Watts or lower.
It is typically expected you will see chargers rated at 15W, 27W, 45W, 60W, 100Watts . So just to be clear a 45Watt charging must now support 15W and 27W as well as 45Watts!

The latest specification also supports authentication of chargers this enables devices to check they are being powered from a genuine charger. We will have to wait and see how the charger market progresses with this, but it could be a significant shake up in the charger market.

As you would expect the engineers at Cambrionix have been busy working on our range of USB Type-C boards and are currently testing prototype units!

The Fundamentals Of Signal Generation

Erik Diez (Keysight/Agilent Technologies) wrote a great article in Electronic Design describing the fundamentals of signal generators - indispensable tools for developing and testing electronic devices and systems.

Being from Keysight, of course they lay claim to the beginnings of the electronic test-and-measurement industry: the model 200A audio oscillator for the Walt Disney Company—in 1940, used for the movie “Fantasia.”
Today, typical applications include RF/IF signal generation and LO substitution, as well as radar, GPS, and avionics signal simulation.  In modern wireless communications systems, signal generators supporting a range of digital-modulation formats are commonly used to test digital receivers and transmitters against increasingly complex requirements. 


Friday, August 19, 2016

What's a "True Pulse Generator"?

Pulse generators often originate with analog designs and produce adequate rectangular waveforms.  But true pulse generators use all-digital techniques to create pulses for improved precision.

AIM-TTi's TGP3100 Series of generators are true pulse generators that can generate precision pulses from 1 mHz up to 50 MHz with pulse width and delay resolutions of 100 psec. Single and dual channel models are available, both featuring large graphic LCDs for simultaneous text and waveform information. The TGP3100 Series are true pulse generators using all-digital techniques, but they can also act as high performance noise generators and as function/arbitrary generators - making them truly universal waveform generators. 

The TGP3100 Series features independently variable rise and fall times that can be set from 5 nsec up to 800 seconds. PWM and PDM (pulse width and pulse delay modulation) are incorporated. Unlike many other pulse generators, the TGP3100 series can perform linear and logarithmic sweeps of all waveform types, as well as extensive internal/external modulation of all waveforms (e.g. AM, FM, PM, SUM, FSK and BPSK etc.), double pulse, and user-defined pulse patterns.

A high drive capability output stage can drive 20 Vpk-pk into a 50 Ohm load. The fully variable output voltage can be load-impedance compensated over a wide range with a minimum output level of 10 mVpk-pk.  Sine waves are available up to 50 MHz and fifteen other standard waveforms are provided. Arbitrary waveforms have 16-bit resolution with an 800 Msample/sec rate.

With the TGP31x2 dual versions, either output can be triggered by the other channel to set up a complex and versatile inter-channel trigger scheme without requiring external connections. A USB flash drive interface on the front panel can store results or setups, and the TGP3100 series can be externally controlled via USB and LXI compliant LAN interfaces (GPIB optional).  Waveform Manager Plus for Windows software is included at no extra charge.  TGP3121/ TGP3151 are the single-channel 25/50MHz models, and TGP3122/TGP3152 are the dual-channel 25/50MHz models. 

Made by Aim-TTi, a leading European test equipment manufacturer, the TGP3100 True Pulse Generators are available now from Saelig Company, Inc. Fairport, NY. www.saelig.com 

Thursday, August 18, 2016

How To Make Great Oscilloscope Measurements

Daniel Bogdanoff from Keysight wrote an excellent article on how to make great (i.e. useful/accurate) measurements using your oscilloscope. He states that proper signal scaling is crucial for optimizing measurements. The signal’s scaling on screen affects sample rate and bits of resolution, which in turn affects your measurement’s accuracy. Both horizontal scaling and vertical scaling influence your measurement in different ways. 
Signal-acquisition time also affects the sample rate of the scope.
Sample Rate = Memory Depth/Acquisition Time
Memory depth of the scope can be small or large depending on what scope you have.  The acquisition time is set by adjusting the time-per-division setting on the oscilloscope. As the acquisition time increases, the sample rate will have to decrease in order to fit the entire acquisition into the scope’s memory. Having an appropriate sample rate for time-dependent measurements (frequency, pulse width, rise time, etc.) is important.
He tackles signal vertical and horizontal scaling and resolution (bits) too in the article.  Increasing the vertical scaling of the signal enabled a much more accurate VPPmeasurement with a standard deviation that’s 15 times smaller.

Wednesday, August 17, 2016

Innovation! Pizza ATM Serves Up Pies on College Campus!


GizMag (now "NewAtlas") reports that a French company is installing a Pizza ATM at Xavier University in Cincinnati, Ohio, in time for the upcoming semester. Available 24/7, customers use a touch screen to select toppings, pay their US$9, and wait three minutes for a boxed, 12-inch pie to slide out the slot.

Similar to the Let's Pizza machines, the Pizza ATM is stocked with prepared pizzas, including a precooked base and added toppings, which are stored in boxes at 37.5° F (3° C). The machine then selects the ordered pizza and places it in front of the oven. A mechanism lifts the lid of the box, pushes both into the convection oven, and lifts the pizza out of the box where it cooks in 3 minutes at 500° F (260° C).

Once cooked, the pizza is then placed back in the box and dispensed to the customer. An onboard computer manages the cold storage and the pizza expiration dates, as well as the cooking times, browning and oven temperature. The machine holds up to 70 pies, which may need to be restocked often depending on other late-night campus dining options.

If the machine malfunctions or is running low on stock, it sends an alert to the owner's phone. The owner also has control over the menu and pricing, changing them according to demand. Although pizza vending machines have been dishing out pizzas in Europe for over a decade, Paline says this is the first time a pizza vending machine has been installed in North America.

If you want a Pizza ATM for your personal use, it'll set you back $55,000.

Tuesday, August 16, 2016

Elektor Reviews the Siglent SDG830 Signal Generator

If you need a signal generator fairly often in your home lab, the attractively priced SDG830 is a very good choice. For your money you get an excellent instrument with many options that delivers good waveforms and is packaged in a sturdy case.

The generated waveforms look nice, and the sine wave looks very clean on the scope screen. This was confirmed by measurements with our Audio Precision analyzer: over the entire audio range (and even above it) the harmonic distortion was under 0.025%, which is an excellent figure when you consider that the DAC in the instrument is a 14-bit type. At the upper end of the frequency range (30 MHz) the sine waveform still looks clean with no visible jaggies, which is a sign of a properly dimensioned output filter.

Siglent supplies the PC software EasyWave with its signal generators, which you can use to compose your own waveforms. The program looks a bit outdated on the graphical front, but it does what it is supposed to do and has quite a few options. You can use mathematical functions to create a waveform, and you can adjust an existing waveform by simply overwriting sections with the mouse cursor on the screen. The signal generator can be connected to the PC through a USB cable, but you can also put a CSV file on a USB stick and plug it into the USB port on the front panel.

Sounds like they like it!

Get yours here for only $332!  http://www.saelig.com/product/sdg830.htm