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KickStart by Mike Tooley Part 12: Your first ‘scope Our occasional KickStart series aims to show readers how to use readily available low-cost components and devices to solve a wide range of common problems in the shortest possible time. Each of the examples and projects can be completed in no more than a couple of hours using ‘off-the-shelf’ parts. As well as briefly I have very fond memories of my first oscilloscope. Built on the kitchen table more than 60 years ago, this rather dangerous instrument used a 3.5-inch (90mm) ex-surplus VCR138 cathode ray tube (CRT) together with an assortment of octal-based valves and a 1.2kV high-tension power supply. Despite the challenge in assembling it, the instrument proved to be something of a revelation, providing me with an insight into what was going on inside the circuits I was experimenting with. Not surprisingly, I quickly became convinced that a ‘scope was going to be a permanent addition to my test bench. So, flushed with success, I set about designing an improved version using a 5-inch VCR97 tube with an even more dangerous 2kV supply! Since then, I’ve worked my way through at least two dozen ‘scopes of different types and specification, some costing as little as £25 to several costing well over £5,000. My current inventory of test equipment includes a fast digital storage oscilloscope (DSO), a generalpurpose USB ‘scope that connects with my desktop PC, laptop, tablet and phone, and three elderly CRT-based scopes that adorn the shelves in my workshop. explaining the underlying principles and technology used, the series will provide you with a variety of representative solutions and examples along with just enough information to be able to adapt and extend them for their own use. This twelfth instalment deviates from earlier parts by taking time out to introduce you to an item of test equipment that will undoubtedly become invaluable as you progress with your interest in electronics. We provide some valuable pointers for those who are about to purchase an oscilloscope for the first time or who might be planning to upgrade an instrument in the near future. nD isplay of signal waveforms: the shape of a wave can indicate the absence of linearity and the presence of distortion, as well as the presence of noise, unwanted harmonics, and other undesirable signal components nM easurement of signal amplitude (peak or peak-to-peak values) nM easurement of signal frequency/ period nM easurement of time delay and the rise and fall time of rectangular pulses nM easurement of phase change and phase difference between signals nM easurement of dc levels and offsets that may be superimposed on ac signals (it is possible to measure dc voltage using an oscilloscope, but an ordinary bench voltmeter will invariably do a much better job) n I nvestigation of transients and other non-repetitive short-duration phenomena nO bservation of drift and other longterm variations that may affect signal characteristics such as amplitude, frequency and phase. Choosing an instrument For most electronics enthusiasts, the acquisition of an oscilloscope represents a significant long-term investment. It therefore merits careful cons ider ation based on several What can an oscilloscope do? Before we describe the range of instruments that you might want to consider as candidates for a ‘first ‘scope’, it’s worth pondering on what the instrument can do, and what it might do for you. The key point is that an oscilloscope can provide a plethora of information about what is going on in a circuit. In effect, it will allow you to ‘see’ into the circuit, displaying waveforms that correspond to the signals and voltages present. Oscilloscopes can be used in a wide variety of situations, including: 42 Fig.12.1. Conventional analogue (bottom) and digital storage ‘scope (top) displaying the same waveform. Practical Electronics | July | 2023 factors, paramount among these is understanding your current and future test and measurement requirements. Unfortunately, due to a wide variation in features, displays, controls and specifications offered, the choice of instrument can often be bewildering. The main categories of oscilloscope can be summarised as follows: nS elf-contained digital storage ‘scopes (DSO) in both bench and portable versions nD SO with a USB connection to a host PC, laptop or tablet computer nS ound card ‘scope software running on PC, laptop or tablet computer nO l d e r, a n a l o g u e C R T- b a s e d oscilloscopes. Within each of these main categories there are a host of sub-categories. For example, ‘scopes with multi-channel capability, high-resolution ‘scopes, ‘scopes with built-in signal/waveform generators, and ‘scopes designed specifically for automotive and other specialised applications. DSOs combine elements of both hardware and software that work together to provide all the functionality of a conventional ‘scope combined with additional features such as spectrum analysis, data logging, and digital measurement of voltage, time and frequency. In many cases you may find that a DSO will augment or replace several items of existing test equipment. However, despite these plus points, it might be worth considering some of the alternatives before homing in on a bench DSO. Available in plentiful quantities on the second-user market, an older CRT-based oscilloscope can be a very cost-effective solution. Whilst such instruments can deliver excellent performance at low cost, they are unlikely to have features such as waveform storage, on-screen measurement data and automatic adjustment of controls. One other consideration worth mentioning is the relatively large size and weight of CRTbased instruments when compared with modern DSO. If you can live with these limitations, you might find that a secondhand analogue instrument is a good and inexpensive choice. Another alternative might be a USB DSO. These budget-priced instruments offer a compact alternative to bulky and relatively expensive benchtop instruments. You can now fit a 200MHz, 1 GS/s instrument together with probes and accessories into a laptop bag and new functionality can be delivered through manufacturer software upgrades and active community support. A PC soundcard-based ‘scope can be a viable alternative if you are only interested in displaying audio frequency waveforms over a limited frequency range (eg, 100Hz to 10kHz). A high-performance sound card with fast sampling and low noise will give better results but you will need a means of calibrating the ‘scope (see Getting started on p.45). You should also note that, while soundcard ‘scopes can work well for repetitive waveforms, triggering can be difficult when displaying irregular waveforms and pulses. Measurements of rise- and fall-times will almost certainly be wildly inaccurate. One further cautionary note is that the input impedance offered by a soundcard will typically be around 50kΩ. This is very much lower than the standard 1MΩ associated with conventional instruments. Questions that you need to answer To help you identify a suitable type of instrument it is worth answering a few questions. 1. Where will you use the instrument? Will the ‘scope only be used on the bench where an AC supply is available, or do you need a portable instrument that can operate from internal batteries? 2. Would you consider an older secondhand instrument as an alternative to a more modern digital instrument? Second-hand instruments of good specification are readily available and can usually be obtained very cheaply. However, due to the use of a cathode ray tube (CRT) display, older secondhand instruments tend to be quite bulky, relatively heavy, and often require a significant amount of bench space. They may also be lacking several of the more useful features available from digital Fig.12.2. Controls and adjustments available on a typical low-cost dual-channel DSO. This 25MHz instrument offers sampling rates of 250MS/s with a resolution of 8-bits and is fitted with a 145mm (5.7-inch) 320×240 LCD. Practical Electronics | July | 2023 43 instruments, such as internal memory and the ability to display information as text. 3. Would you consider a USB instrument as an alternative to a standalone ‘scope? USB instruments can be extremely costeffective but require the services of a host PC or laptop (some can also be used with phones and tablets). If you choose a USB instrument it is important to check that it is compatible with both the hardware and operating system of your host computer. Some USB instruments may only support a limited number of operating systems, so it is worth checking that you have the correct version installed. 4. What display type/size is best for you? Larger screen sizes are much easier to read (and consequently obtain information) but usually mean a larger instrument. Smaller displays can be cramped and difficult to read but note that if you decide upon a USB ‘scope (rather than a freestanding instrument) your display size will be determined by the PC, laptop or phone that you connect it to. Note also that a typical laptop display can be very much larger than the integrated display fitted to a stand-alone bench instrument. The facility to ‘screen grab’ a display and store it as an image (often in JPG, PNG, or BMP format) can provide you with a useful record for future reference. Many of the images used in this article were produced this way. 5. Do you need an instrument that will accurately display transients (ie, rapid changes in signal levels)? rather than repetitive waveforms? If yes, you may require sophisticated trigger facilities to detect the change then capture and display it. Repetitive waveforms do not generally require sophisticated triggering. Note that the memory facility found in a DSO will enable you to capture transient events and analyse them later. This can be one of the key reasons for choosing a DSO over a conventional analogue CRT-based instrument. 6. Over what frequency range will you be measuring? If you only intend to work with audio and low-frequency signals (eg, signals up to 100kHz, or so) you will only require an instrument with a bandwidth of up to about 10MHz. If you need to work with high frequency signals (particularly non-sinusoidal) it may be essential to have an instrument with a bandwidth of 50MHz, or more. As a rule of thumb, the author recommends choosing an instrument with a quoted analogue bandwidth that is at least five-times higher than the highest signal frequency to be measured. Note that cost can be a significant factor here. For example, 10MHz, 25MHz, and 50MHz versions of popular USB ‘scopes from Pico technology are currently priced at £115, £185, and £299 respectively. So, if you’re not planning to work with high-frequency signals you might opt for the lower bandwidth and save yourself some cash. 7. How many channels do you need? Most instruments provide two-channel operation, but ‘scopes with four or more inputs will allow you to display, measure and compare several signals simultaneously. A useful feature of most dual channel instruments is that they will allow you to display the result of adding (A+B) or subtracting (A-B) two input signals. This latter feature can be invaluable if you need to compare two signals, displaying what is present in one signal that’s absent from the other. 8. How much memory do you need? This is a pertinent question if you are purchasing a digital storage oscilloscope (DSO) rather than a traditional analogue instrument. When making measurements with a DSO your ‘scope will effectively be capturing only a small portion of the signal that you’ve applied to it. How much of the signal gets captured depends on how much memory is available to store the data. DSO memory buffers range considerably in capacity, from about 8K data samples in budget instruments to around 128M data samples in more expensive DSOs. 9. What resolution and sampling rate do you need? This is another important question if you are intending to purchase a DSO. Fig.12.3. Controls and adjustments available on a typical dual-channel CRT-based analogue oscilloscope. This elderly generalpurpose ‘scope is typical of those available at bargain prices on the second-hand market. It has a 130mm (5.1-inch). screen. 44 Practical Electronics | July | 2023 The resolution of a DSO is expressed in terms of the number of bits used in the conversion of the analogue signal to its digital equivalent. For most purposes a resolution of 12 bits will be adequate – but do remember that sampling rate is also important. To be able to perform a detailed display of high-frequency signals it is important to match bandwidth with the real-time sampling rate. For example, to analyse a signal in an analogue bandwidth of 100MHz, a sampling rate of 500MS/s will produce a display with five points plotted for each cycle of the waveform. A sample rate of 1GS/s would produce double the number of points and the waveform will consequently be drawn more precisely. As a rule of thumb, the author recommends choosing an instrument that supports sampling rates that are at least ten-times greater than the highest expected signal frequency. 10.What range of input voltages do you expect? Some low-cost instruments may have a limited input voltage range (eg, 50V) and others may only be DC-coupled (the popular Hantek 6022 USB ‘scope suffers from both limitations). For automotive and power applications an appropriately rated input is essential with switchable AC and DC coupling. A ×10 probe can also assist by reducing the voltage present at the ‘scope’s input terminal. Fig.12.4. The budget-priced Hantek 6022BE USB DSO used in conjunction with the author’s Linux-based laptop. Note the size and clarity of the display. 11.Do you need additional features such as the ability to read protocol strings? Modern DSOs offer a vast array of additional features that can sometimes become invaluable. Some DSOs incorporate serial bus triggering and decoding with supported protocols that can include I2C, SPI, UART, RS-232, CAN, LIN, and the list goes on. Others may have inbuilt digital waveform generators capable of producing arbitrary test signals. While none of these features are likely to be deal breakers to new users, they may at some point be something that you wouldn’t want to be without. As can be seen from Fig.12.2 and Fig.12.3, many of the controls present in a DSO have direct equivalents in a CRT-based instrument. Others, such as menu selection and function keys are unique to the DSO. The usual input and trigger selectors are present, so too is the trigger level control. As with a CRT-based instrument, the timebase control is marked in terms of ‘time per division’, – however, it may also be possible to configure a DSO in terms of ‘time per scan’ which may make more sense for some measurements. For a dual-channel DSO you can select which of the two channels (or both) to display on the screen – but, unlike a CRT-based analogue ‘scope, each of the two channel traces can be displayed in a different colour. Voltage ranges are selected in much the same way as for a CRT-based ’scope, but an auto-ranging facility may also be included. This option can be particularly useful if you need to switch between different input signals. How easy is it to use? Getting started If you’ve not used a ‘scope before the controls and adjustments can be baffling. In Fig.12.2 and Fig.12.3 we’ve shown the controls and adjustments found on a typical mid-range DSO and CRT-based instruments. You might find that it takes some time to get familiar with these, but the investment in time and effort can be very rewarding as it will allow you to get the very best out of the instrument. The procedure and adjustments differ according to the type of waveform being investigated and whether the instrument is being used in single- or dual-channel mode (the latter displaying two waveforms simultaneously). The following sequence of adjustments will provide you with a starting point for making most oscilloscope measurements. Many DSOs incorporate automated measurement tools that can simplify most common tasks (such as voltage, time or frequency measurement) but knowing how to make manual measurements can help you understand and check the validity of automatic measurements. 1.  Connect power and switch the instrument ‘on’. Most DSOs will take a short time to complete their initial boot sequence (after which a display will appear). Older CRT-based instruments Practical Electronics | July | 2023 may take longer for the CRT’s heater to warm and produce a display. On a CRT-based instrument you may need to set the brightness and focus controls to mid-position and then adjust them for a reasonably bright and properly focussed trace (this should appear as a horizontal line on the screen). 2. Adjust the vertical and horizontal shift controls so that the trace aligns with the graticule/scale. Note that older CRT-based ‘scopes often have a trace rotation adjustment that can be useful if the CRT is out of alignment with an external scale. 3.  Set the horizontal (timebase) range to 1ms/div and the variable timebase control to the calibrate (CAL) position. 4. Set the vertical (voltage) range to 1V/ div and the variable voltage control to the calibrate (CAL) position. 5. Set the input coupling to AC. 6. Set the trigger source to Channel A and the trigger mode to AUTO. 7. Attach probes to the instrument and, if necessary, check and compensate the probes (see later). 8.  Connect the probe ground clip to common/ground on the circuit under investigation and then connect the probe tip to the desired test point. 9. Re-adjust the time and voltage range controls to obtain a display for measurement purposes. The trigger controls can also be adjusted at this stage to select the exact point on the waveform at which triggering occurs, Worth considering? Having decided on the type of oscilloscope that most closely meets your needs, here is a shortlist of popular instruments of each type that are worth considering. 45 Fig.12.5. The budget-priced Hantek 6022BE USB DSO used in conjunction with an Android-based Amazon Fire tablet. This set-up is ideal for portable use. For those on a strict budget or those who might prefer a basic CRT display, there are numerous instruments to choose from. We’ve included several of those in the list that follows. Rigol DS1000Z series (stand-alone DSO) This is a series of 2- and 4-channel oscilloscopes offering real-time sampling rates of up to 1GS/s and analogue bandwidths from 50MHz to 200MHz. S-versions also have a 2-channel waveform generator and Plus-versions add 16 digital input channels. Prices range from about £360 to around £480. Fig.12.6. The budget-priced Hantek 6022BE USB DSO used in conjunction with the author’s mobile phone. Despite its small size the display is still eminently usable. Hantek DSO2000 series (standalone DSO) Hantek’s DSO2000 series oscilloscopes offer an excellent specification for a very modest outlay. They offer two channels with bandwidths of either 100MHz or 50MHz and a maximum sample rate of 1GS/s. Vertical sensitivity ranges from 2mV/div to 10V/div. Two of the instruments in this range (DSO2D10 and DSO2D15) also have a 25MHz in-built arbitrary waveform generator (AWG). The instruments also provide digital readout of voltage and frequency with serial bus data decode and protocol analysis. Prices range from £175 to £275. Hantek 6022BE (USB DSO) This low-cost 20MHz USB instrument is designed for the entry-level user. It offers dual-channel operation and is supplied with probes and accessories. Perhaps, not surprisingly for this popular budget ‘scope, there is a large userbase, and several free and open-source packages are available as an alternative to the software supplied by Hantek. The ‘scope can be used with different types of computer and different operating systems, including Windows, Linux, and Android (see Figs.12.4 to 12.9). The 6022BE has several important limitations, the most noteworthy is that the input is DC coupled and the input voltage range is limited to a maximum of 30V without external attenuation. An AC input modification has been published, see Going further for details. The 6022BE is available from several on-line sources at prices ranging from around £60 to £100. Fig.12.7. The freely available OpenHantek software is an excellent alternative to Hantek’s own software. Note the useful information that appears as text at the bottom of the screen. 46 Practical Electronics | July | 2023 Fig.12.8. The OpenHantek software incorporates a useful zoom facility that will allow you to inspect a small portion of the applied signal (in this case a 600ns window at the leading edge of a pulse). PicoScope 2200A series (USB DSO) This is 2-channel 200MHz USB ‘scope operates with sampling rates of up to 1GS/s. The supplied software (available for free download) is well supported and easy to use with free updating. The software incorporates various useful features including on-screen waveform measurement data, mask limit testing, serial bus decoding and versatile digital triggering. As an additional bonus, the instrument also incorporates an arbitrary waveform generator (AWG). Hameg HM203 (second-user analogue ‘scope) Ease of operation and a well-designed front panel layout made this robust lowcost instrument ideal for use in education and training, and this helped ensure its popularity in a wide range of educational contexts. The HM 203 provides basic two-channel operation coupled with a bandwidth of 20MHz. Prices range from around £50 to £100. Philips PM3215 (second-user analogue ‘scope) Designed for general purpose laboratory and TV/video servicing, this competent 50MHz oscilloscope offers a maximum sensitivity of 2mV/div and a time-base range extending from 0.5s/div to 0.1µs/ div. Prices range from about £90 to £180. Telequipment D83 (second-user analogue ‘scope) The D83 is a versatile laboratorygrade instrument that uses two plugins that are also compatible with Telequipment’s popular D75, D63 and DM63 oscilloscopes. The available vertical system plug-ins include the V4 dual-trace amplifiers, the V3 singlechannel differential amplifier, the V1 single-channel amplifier, and the V5 single-channel amplifier with delay line (primarily intended for the DM63/ D63 mainframes that have no built-in delay lines). The instrument offers a sensitivity extending from 5mV/div to 20 V/div and a bandwidth of DC to 50MHz. Prices range from about £60 to £120. and a timebase adjustable to 2ns/div. The instrument provides on-screen cursors for accurate voltage and time measurement with CRT readout of parameters including voltage, time and frequency. Prices range from £150 to around £250. Tektronix 2445B (second-user analogue ‘scope) Developed in the late 1980s, the 2445B was one of the last of a long series of well specified analogue oscilloscopes developed by Tektronix (a market leader since 1946). The 2445B offers four channels, a bandwidth of 150MHz Soundcard-based ‘scopes (various) This, potentially zero-cost solution, involves using a soundcard (either internal or external) together with oscilloscope software (see Going further for details). Recommended packages are Christian Zeitnitz’s Soundcard Scope (see Fig.12.10) Practical Electronics | July | 2023 Fig.12.9. The OpenHantek software offers spectral analysis of the signal under investigation. In this case you can see the odd harmonic components present in a 1kHz square wave signal (note that the second and fourth harmonic can also be seen at low level). and Virtins Multi-Instrument (see Fig.12.11). Please note the restrictions on performance that we mentioned earlier (see Fig.12.12 for an example of poor square wave performance obtained from soundcard instruments). A word about probes Earlier we mentioned the importance of using a purpose-designed ‘scope probe when taking accurate measurements. If your ‘scope doesn’t come with a set of probes you will need to acquire one or more switchable ×1 and ×10 probes (see Fig.12.13). Note that a ×10 probe provides an attenuation of 10 times. 47 Fig.12.10. A typical soundcard ‘scope display produced by Christian Zeitnitz’s excellent Soundcard Scope software. The display shows low-frequency triangle and sine waveforms (red and green traces respectively). Fig.12.11. Virtin’s powerful and comprehensive Multi-Instrument software being used with a PC soundcard to investigate and measure the total harmonic distortion (THD) present in a 1kHz sinewave signal. It is important to be aware that ‘scope probes are designed to be matched to a particular instrument and require initial calibration before use. It is also worth checking probe 48 compensation every time you set up your ‘scope. This can usually be carried out quickly and easily using the internal square wave reference source that’s available on most instruments. If you don’t have a calibration source, you can use a square wave source or use the handy ‘scope calibrator described in our Get Testing Teach-In 9 series (see Going further for details). An important requirement of a ‘scope is that it should faithfully reproduce signals and pulses of fast duration and that it should not load the circuit to which it is connected. The standard input resistance of most ‘scopes is 1MΩ, but appearing in parallel with this is a small (stray) capacitance of around 20pF, as shown in Fig.12.14(a). Note that this shunt capacitance also appears in parallel with that of an input cable and this can be appreciable (a typical 50Ω coaxial cable has a capacitance of around 100pF per metre). Fig.12.14(b) shows the basic arrangement of an uncompensated ×10 probe. A close-tolerance series resistor of 9MΩ forms an attenuator in conjunction with the 1MΩ input resistance of the ‘scope. The probe tip then imposes a load of 10MΩ rather than the 1MΩ of the ‘scope alone. The unfortunate consequence of this arrangement is that the 9MΩ probe tip resistance forms a low-pass filter with the capacitance of the cable (CC) acting in parallel capacitance with the nominal 20pF input capacitance of the ‘scope. This severely reduces the high frequency response of the ‘scope and probe combination. Compensation can be achieved in various ways to improve the frequency response. Fig.12.14(c) shows how a Fig.12.12. (below) Comparison of a soundcard ‘scope (left) with a DSO (right) displaying a 1kHz square wave signal. Of particular note is the rise and fall times displayed by the soundcard instrument. Practical Electronics | July | 2023 Fig.12.13. Three different oscilloscope probes (see text). Fig.12.15. Compensation adjustment at the tip of a ‘scope probe. Fig.12.16. Compensation adjustment at the ‘scope input connector. Fig.12.14. Equivalent circuits of the input of an oscilloscope with probes. low-value trimmer capacitor can be introduced in parallel with the 9MΩ probe tip resistor. This arrangement is used in some commercial probes. An alternative arrangement, shown in Fig.12.14(d), uses a fixed capacitor in parallel with the 9MΩ probe tip input resistor and a shunt-connected trimmer capacitor fitted at the ‘scope input. In Fig.12.13, probe A incorporates a compensation adjustment at the tip while the compensation for probe B is adjusted at the ‘scope input connector. Practical Electronics | July | 2023 Fig.12.17. Typical waveforms obtained during the compensation of a ‘scope probe. Probe C is designed specifically for use with soundcard ‘scopes and does not incorporate any means of compensation. Fig.12.15 shows how the trimmer adjustment is made accessible at a probe’s tip, while Fig.12.16 shows the equivalent adjustment point at a probe’s BNC connector. In either case, after applying a square wave calibrating signal to the probe tip (see Going further) the compensating trimmer is simply adjusted for the best square wave (in other words, a square wave with fast rise and fall times and with no discernible overshoot). Fig.12.17 shows typical waveforms obtained during probe compensation. Going further This section details a variety of sources that will help you locate the component parts and further information that will allow you to acquire and get the best out of your oscilloscope. It also provides links to relevant underpinning knowledge and manufacturers’ data sheets. 49 Table 12.1. Going Further with your first ‘scope Topic Source Oscilloscope theory and practice A general introduction to the use of oscilloscopes can be found in Part 2 of Electronics Teach-In 9. Electronics Teach-In 9 is available direct from PE at: https://bit.ly/pe-eti9 Oscilloscope suppliers The web provides numerous oscilloscope manufacturers and suppliers. Those mentioned in this article include: Picotech: www.picotech.com Rigol: www.rigol-uk.co.uk Hantek: www.hantek.com Oscilloscopes can also be purchased from most large electronic component and test equipment suppliers. Oscilloscope calibrator The Test Gear Project featured in Part 2 of Electronics Teach-In 9 provides an accurate 1kHz square wave calibration signal with an amplitude of 5V and suitably fast rise and fall times. The ‘scope calibrator is small, inexpensive and easily constructed. Electronics Teach-In 9 is available direct from PE at: https://bit.ly/pe-eti9 Soundcard oscilloscopes Several useful software packages are currently available for free download. Two that can be highly recommended are Soundcard Oscilloscope by Christian Zeitnitz and Virtin’s Multi-Instrument (the latter is also designed to work in conjunction with Virtin’s own range of USB DSO). OpenHantek Conceived as an alternative to the official Hantek DSO software for Linux users, this package now works with Microsoft Windows and Apple macOS. OpenHantek is also compatible with Voltcraft, Darkwire, Protek and Acetech USB DSOs. OpenHantek software can be downloaded from: http://openhantek.org/ Second-user oscilloscopes Second-user oscilloscopes appear regularly at on-line suppliers and auction sites. eBay is a good source, but do check sellers’ feedback and postage/carriage charges. Hantek 6022BE modification An AC input modification for the Hantek 6022BE can be found at: https://bit.ly/pe-jul23-han This modification is only recommended for those with electronics experience. GET T LATES HE T COP Y OF TEACH OUR -IN SE RIES AVAILA BL NOW! E Order direct from Electron Publishing PRICE £8.99 (includes P&P to UK if ordered direct from us) Notes Soundcard Oscilloscope is available from: www.zeitnitz.eu/Scope_en Virtin’s Multi-Instrument can be downloaded from: www.virtins.com/index.shtml EE FR -ROM CD ELECTRONICS TEACH-IN 9 £8.99 FROM THE PUBLISHERS OF GET TESTING! Electronic test equipment and measuring techniques, plus eight projects to build FREE CD-ROM TWO TEACH -INs FOR THE PRICE OF ONE • Multimeters and a multimeter checker • Oscilloscopes plus a scope calibrator • AC Millivoltmeters with a range extender • Digital measurements plus a logic probe • Frequency measurements and a signal generator • Component measurements plus a semiconductor junction tester PIC n’ Mix Including Practical Digital Signal Processing PLUS... YOUR GUIDE TO THE BBC MICROBIT Teach-In 9 – Get Testing! Teach-In 9 A LOW-COST ARM-BASED SINGLE-BOARD COMPUTER Get Testing Three Microchip PICkit 4 Debugger Guides Files for: PIC n’ Mix PLUS Teach-In 2 -Using PIC Microcontrollers. In PDF format This series of articles provides a broad-based introduction to choosing and using a wide range of test gear, how to get the best out of each item and the pitfalls to avoid. It provides hints and tips on using, and – just as importantly – interpreting the results that you get. The series deals with familiar test gear as well as equipment designed for more specialised applications. The articles have been designed to have the broadest possible appeal and are applicable to all branches of electronics. The series crosses the boundaries of analogue and digital electronics with applications that span the full range of electronics – from a single-stage transistor amplifier to the most sophisticated microcontroller system. There really is something for everyone! Each part includes a simple but useful practical test gear project that will build into a handy gadget that will either extend the features, ranges and usability of an existing item of test equipment or that will serve as a stand-alone instrument. We’ve kept the cost of these projects as low as possible, and most of them can be built for less than £10 (including components, enclosure and circuit board). © 2018 Wimborne Publishing Ltd. www.epemag.com Teach In 9 Cover.indd 1 01/08/2018 19:56 PLUS! You will receive the software for the PIC n’ Mix series of articles and the full Teach-In 2 book – Using PIC Microcontrollers – A practical introduction – in PDF format. Also included are Microchip’s MPLAB ICD 4 In-Circuit Debugger User’s Guide; MPLAB PICkit 4 In-Circuit Debugger Quick Start Guide; and MPLAB PICkit4 Debugger User’s Guide. ORDER YOUR COPY TODAY: www.electronpublishing.com 50 Practical Electronics | July | 2023