Review Of OWON HDS Series 2-Channel Handheld Digital Storage Oscilloscope

If you’re looking for a cheap oscilloscope option, this isn’t really it (but, in reality, it is pretty affordable), considering the full set of features it boasts, the OWON HDS Series 2-Channel Handheld Digital Storage Oscilloscopes are great handheld oscilloscope options for both the professional and the hobbyist.

The HDS Series features a 20 MHz bandwidth, which provides a sample rate of 100 MS/s. The results are detailed waveforms on both channels, especially compared to less expensive handheld units with lower sample rates. If detail and power are important to you in a handheld product, this is the oscilloscope for you.

Another huge feature of the HDS Series oscilloscopes working in its favor is the fact that it has 2 digital channels, something many other handheld units just don’t have.

The OWON HDS Series oscilloscopes feature many of the same built-in functions that the OWON benchtop units have, such as automated measurements like peak-to-peak, period and frequency, as well as math formulae like FFT, subtract, multiply, etc. You can manually adjust the range or you can opt to use the handy auto-range feature.

The screen is a 3.7 inch across color LCD version which provides an easy to view readout. It has a rechargeable battery and charger, and it has USB plugin functionality, which allows a user to connect it to your PC and download and print stored waveform data. It even includes a durable carrying case.

Drawbacks? Only a few. Overall, the ‘fit and finish’ could be a bit better on the unit, as it’s mostly plastic. The readout screen isn’t bad, but it could be brighter and if it is used in a darker situation, it may require an auxiliary light source. Basically, the features are all there, but the unit might not be the most durable. Considering it has the features of products that are 3 times more expensive, it is a justifiable trade-off in terms of durability.

OWON HDS Series 2-Channel Digital Portable / Handheld Oscilloscopes: Perceived Trade Offs:

After review of this blog, no doubt the reader has noticed a strong correlation between the price tag of the OWON HDS Series oscilloscopes and the features.

Primarily, there is a strong correlation between the bandwidth / sample rate and the price, as well as the number of channels available.

To a lesser degree, the user interface and ease of use also play a role in price.

A user should always consider trying to get the higher bandwidth wherever possible. The lower the bandwidth, the less powerful and useful your device will become.

With OWON HDS Series Handheld oscilloscopes, there’s an even greater jump in price with additional features. That is the cost associated with miniaturization.

To summarize, think of it like this: If a user is a hobbyist, the need is where no more than a couple hundred dollars on your scope should be spent. If the user is a professional, it should be expected to have a standard budget range of anywhere between $250.00 and $5000.00.

In other words, the pricing is directly correlated to the strength and features of handheld and benchtop oscilloscopes.

Established in 1990, OWON is based in China, specializing in the manufacture of oscilloscopes, waveform generators, multimeters, and programmable DC power supplies. These capable instruments are distributed to customers in the aerospace, automotive, communication, defense, electrical, and education industries in more than 80 countries across the globe.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that provides unique electronic test & measurement tools for design engineers, test engineers and production engineers. Visit our online store to review and purchase OWON HDS Series Handheld Oscilloscopes – www.northtreeassociates.com

 

9 Factors to Consider When Choosing an Oscilloscope

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If you’re involved in electronics, you’ll probably have an oscilloscope on your bench. As electronics become more complex almost daily, sooner or later a new oscilloscope will be in order. How to choose the right one for your applications?

Factors to consider:

Remember that the bandwidth specification of an oscilloscope is the frequency of the “-3 dB point” of a sine-wave signal of a particular amplitude, e.g. 1 Vpp. As the frequency of your sinewave goes up (while keeping the amplitude constant), the measured amplitude goes down. The frequency at which this amplitude is -3 dB lower, is the instrument’s bandwidth. This means that an oscilloscope of 100MHz would measure a 1Vpp sinewave of 100MHz at only (approx.) 0.7Vpp. That is an error of about 30%! In order to measure more correctly, use this rule of thumb: BW/3 equals about 5% error; BW/5 equals about 3% error. In other words: if the highest frequency you want to measure is 100 MHz, choose an oscilloscope of at least 300MHz, a better bet would be 500MHz. Unfortunately, this has the most influence on the price…

Understand that today’s signals are no longer pure sine waves, but most of the time square waves. These are built by “adding” the odd harmonics of the fundamental sine wave together. So a 10 MHz square wave is “built” by adding a 10MHz sine wave + a 30MHz sine wave + a 50MHz sine wave and so on. Rule of thumb: get a scope that has a bandwidth of at least the 9th harmonic. So if you’re going for square waves, it’s better to get a scope with a bandwidth of at least 10x the frequency of your square wave. For 100MHz square waves, get a 1GHz scope… and a bigger budget…

Consider rise (fall) time. Square waves have steep rise and fall times. There’s an easy rule of thumb to get to know what bandwidth your scope needs to be if these times are important to you. For oscilloscopes with bandwidths below 2.5GHz, calculate the steepest rise (fall) time it can measure as 0.35/BW. So an oscilloscope of 100MHz can measure rise times up to 3.5ns. For oscilloscopes above 2.5GHz up to about 8GHz, use 0.40/BW, and for scopes above 8GHz use 0.42/BW. Is your risetime the starting point? Use the inverse: if you need to measure rise times of 100ps, you’ll need a scope of at least 0.4/100ps = 4 GHz.

Choose your sample speed. Today’s oscilloscopes are almost all digital. The above steps involved the analog part of the instrument, before it gets to the A/D converters to get “digitized”. Here the bandwidth-to-rise time calculation can help you out: an oscilloscope of 500MHz has a calculated rise time of 700ps. To reconstruct this, you need at least 2 sample points on this edge, so at least a sample each 350ps, or 2.8Gsa/s (gigasamples per second). Scopes don’t come in this flavor, so choose a model with a faster sampling speed, e.g. 5Gsa/s (resulting in 200ps “time resolution”).

Decide on the number of channels. This is easy: most scopes come with 2ch or 4ch configurations, so you can choose what you need. Fortunately prices don’t double from 2ch to 4ch, but it does have a big impact on the price of the instrument. High-end scopes (>=1GHz) have always 4ch.

Calculate how much memory you’ll need. Depending on how much of your signal you want to see in a “single shot acquisition”, get your math right: at 5Gsa/s, you have a sample each 200ps. A scope with a memory of 10.000 sample points, can store 2µs of your signal. A scope with 100M samples (they do exist!) can store 20 seconds! Looking at repetitive signals or “eye-diagrams”, memory is less important.

Think about repetition rate. A digital oscilloscope uses a lot of time calculating. Between the moment of triggering (see next step), having the captured signal on the display, and capturing the next triggered event, most digital scopes “consume” several milliseconds. This results in only a few “photos” of your signal each second (waveforms per second), typically about 100-500. One vendor solved this problem with so called “Digital Phosphor” (from about 4.000 wfms/s to >400.000 wfms/s for the top models), others followed with similar-like technologies (but not always sustained/continuous, rather in bursts). This repetition rate is important because those rare errors and faults in your signal might occur just then when the scope is not acquiring, but busy calculating the last taken acquisition. The higher the repetition rate (wfms/s rate), the higher your chances are of capturing that rare event.

Check what kind of errors you expect to be looking for. All digital scopes have some sort of intelligent triggers on board, meaning you can trigger on more than just the rising or falling edge of your signal. If your repetition rate is high enough, you’ve probably seen that rare glitch every other second. Then it’s nice to have a Glitch trigger.

Think about resolution of LCD display. Small screens with poor resolution can make your life miserable if you cannot see results easily. Buy the largest screen with the best definition your budget will allow.

Some Final Tips

  • Triggering, repetition rate and memory: once you found the rare event with a high wfms/s rate, having the right trigger available is more important than repetition rate, as your scope will trigger only on the (rare) event, which occurs… right: rarely. So you don’t need high rep-rate anymore. Memory can become more important, as to be able to analyze what happened before or after the event.
  • Remember: garbage in is garbage out, so get the bandwidth and rise time issue sorted out first!

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that specializes in providing unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers. You can visit our website at http://www.northtreeassociates.com

NorthTree Associates Introduces OWON XDS Series Multi-Function Oscilloscopes

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The XDS series of oscilloscopes is the latest product release from OWON. With 12‐bit resolution, the XDS series offers the best solution for those who need to measure small signals or be able to read details from a large signal. Highly suitable for Medical, Automotive, Power Supply, and more.

In addition to having a 12‐bit resolution, the OWON XDS series of oscilloscopes are equipped with advanced technology and functions such as advanced trigger and decoding functions, Wi‐Fi and App support along with a capacitance touch screen.

OWON XDS series oscilloscopes come with the OWON 3rd generation technology platform ‐ Xvisual, which advances the performance of the XDS series oscilloscopes over other oscilloscopes available. The new Xvisual platform consists of 3 parts: Low Base Noise, 40M Record Length, 75,000 wfms/s Refresh Rate. One of the main benefits of Xvisual is ease at which the measurement of small signals can be read, and the ability to fully restore the true status of signals.

The XDS series oscilloscope software, provides advanced trigger and protocol decoding functions to help engineers analyze bus protocols and quick positioning. The embedded Wi‐Fi module ensures computers and cell phones can share the display screen to view and control the oscilloscope. Users can also check and save waveform data via App. By saving data via the App, data can be shared between other users.

The optional capacitance touch screen has been designed to look and act similar to a Smartphone – thus being intuitive and easy to start using right out of the box.

Additionally, the OWON XDS is complete mobile test station. It has incorporated the ultra‐thin design of the OWON SDS series oscilloscope, and has a battery option for portable use in the field. Besides the oscilloscope function, the OWON XDS also has function modules such as: a 25 MHz/50MHz single/dual channel(s) arbitrary waveform generator, a digital multimeter and a high precision data logger.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor for OWON oscilloscopes, waveform generators, and programmable power supplies. NorthTree Associates provides unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers.

NorthTree Associates Announces Representation Agreement for OWON Electronic Test & Measurement Equipment

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NorthTree Associates introduces the OWON range of high performance Electronic Test & Measurement Equipment which includes touch screen oscilloscopes, waveform generators, and programmable DC power supplies.

As a touch screen oscilloscope innovator, OWON has achieved various worldwide patent rights, software copyright for their TDS Series Touch Screen Oscilloscopes. Features include: a multi-touch screen, 100MHz to 200MHz bandwidth, 2 or 4 channels, real time sampling rates of 1GS/s to 2GS/s, compact design, high memory depths, and excellent function features.

Other OWON series of oscilloscopes offer bandwidths ranging from 20MHz to 300MS/s, up to 4 channels, channels and a 3.2GS/s sampling rate, making them ideal for both laboratory testing and field service applications across a wide range of industry sectors. High performance features offered by OWON oscilloscopes include isolated inputs for safely carrying out floating measurements, 10M record length for each channel, and a large 8 inch color LCD display screens with 600 x 800 pixel resolution.

In addition to oscilloscopes, NorthTree Associates will also be representing OWON waveform generators, and programmable DC power supplies. The OWON Waveform Generators are versatile waveform generators which derive both function and arbitrary waveforms using Direct Digital Synthesis (DDS) technology, providing stabile, precise, low-distortion signals from DC up to 150MHz, (depending upon model);  all with 14-bit vertical resolution. The features of the OWON Programmable DC Power Supplies include up to 100 output groups with configurable timer, high-resolution LCD display, extremely clean ripple and noise, comprehensive over-voltage over-current over-temperature protection, user friendly interface and panel layout, and variety standard interfaces to meet diverse test requirements.

Established in 1990, OWON is based in China, specializing in the manufacture of oscilloscopes, waveform generators, and programmable DC power supplies. These capable instruments are distributed to customers in the aerospace, automotive, communication, defense, electrical, and education industries in more than 80 countries across the globe.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that provides unique electronic test & measurement tools for design engineers, test engineers and production engineers. www.shop.northtreeassociates.com