Q1 |
What is EMPulse? |
A1 |
EMPulse is a handheld instrument especially designed to locate EMI issues, give a primary check of circuitry at PCB level and pre-compliance EMC immunity checking |
Q2 |
How does EMPulse work? |
A2 |
By generating electrical and magnetic pulses near your PCB design, EMPulse recreates symptoms which could cause equipment to fail during the mandatory CE immunity test. EMPulse can then be used to locate the problem area. |
Q3 |
When do I need EMPulse? |
A3 |
If your equipment has failed the mandatory EMC compliance tests due to ESD or RF immunity and you need to locate a problem. To prevent future design failures, use EMPulse during the initial design stage. |
Q4 |
Can I use EMPulse to replace the CE electromagnetic immunity tests? |
A4 |
No. Equipment will still require mandatory testing, but checking your design with EMPulse will give you a much better chance of passing first time |
Q5 |
How long does it take to set up EMPulse? |
A5 |
A few seconds! Read the manual and see the free video for details. |
Q6 |
it possible to check electronic circuitry before it is placed in a screened enclosure? |
A6 |
Yes, EMPulse gives rapid and repeatable EMI checks on PCB level electronic circuitry |
Q7 |
Can EMPulse exactly locate a problem? |
A7 |
Yes, when synchronised to an oscilloscope, it can precisely locate a signal causing a problem. |
Q8 |
How repeatable are EMPulse results? |
A8 |
Very- Because there are no connections required to the circuitry under test , EMPulse provides very consistent results |
Q9 |
Will EMPulse affect a well-designed PCB? |
A9 |
No. A well laid out PCB with ground plane and no exposed high impedance signals should not be affected by the EMPulse sweep at 10 mm on full power |
Q10 |
What sort of field does EMPulse generate? |
A10 |
EMPulse generates Electrical and Magnetic field of short Uni-polar pulses with low average energy. |
Q11 |
The EMC regulations are regularly being updated, will EMPulse become obsolete like some other EMC test gear? |
A11 |
EMPulse will not become obsolete as the EMI standards are updated. Electronic circuitry will always require fault location and a primary level of immunity |
Q12 |
Can I check internal equipment wiring for electromagnetic immunity using EMPulse? |
A12 |
Yes, use the long side of the large EMPulse probe parallel to a cable to induce pulses into the cable. |
Q13 |
How accurately can I locate a fault without using a oscilloscope? |
A13 |
Usually the problem can be pinpointed simply by sweeping EMPulse while reducing the field strength,The key to locating a fault is to sweep closer or touching the area whilst reducing the power. By setting the power so that it only just affects the problem the area can usually be accurately found. |
Q14 |
Can EMPulse save me money on my new designs? |
A14 |
EMPulse can be used on existing designs to identify sensitive areas at a primary level, if these areas are improved then it may be possible to make savings in the enclosure design. Once changes have been made EMPulse can be used to verify the problem is solved. |
Q15 |
At what stage should I use EMPulse to check my circuit design? |
A15 |
As soon as the circuit is laid out on a PCB and working normally. EMPulse has been developed to assist in locating EMC immunity problem areas in electronic circuits at the earliest opportunity. |
Q16 |
Why does EMPulse have separate Positive and Negative pulse buttons? |
A16 |
Circuits can be affected differently by each polarity, this can sometimes give a clue to the source of the problem. EMPulse uses polarised pulses, which can show up problems that symmetric pulses may not show. |
Q17 |
What are the typical symptoms that can occur in the EUT due to the EMPulse field? |
A17 |
Displays may be corrupted / Power Supplies may glitch or fluctuate / Processors may glitch or reset / Noise may be induced into audio circuits / Memory may be corrupted / Circuits may latch up / Logic may change state erratically. All these symptoms indicate a problem in the circuit design or layout |
Q18 |
How do I sweep a PCB using EMPulse? |
A18 |
EMPulse is held perpendicular to the circuitry and swept parallel to the PCB tracks. On multi layer PCB’s with ground or power planes then both sides of the board need to be checked. |
Q19 |
How do I check a circuit for possible problem areas? |
A19 |
With power applied and the circuit working normally, the EMPulse probe is used to scan within a few cm’s of the electronic circuitry, whilst looking for any signs of malfunction. |
Q20 |
How does the EMPulse oscilloscope sync feature work? |
A20 |
By connecting the EMPulse sync output to the scope trig input, this allows EMPulse electromagnetic field pulse to be aligned on with the ‘scope display and thus allows signals to be interrogated for any EM field affecting them. |
Q21 |
Can I press both Positive and Negative pulse buttons at the same time? |
A21 |
Yes. EMPulse will then generate alternating Uni-polar pulses, which will expose most problems. This is the best way to begin your scan for problem areas. |
Q22 |
Does EMPulse affect signals in ribbon cabling? |
A22 |
Balanced signals and those with a local, well defined return path will not be affected, i.e. balanced ground returns in the cable. Unbalanced signals where the signal return path does not follow the signal may be affected |
Q23 |
What sort of design circuit flaws can EMPulse expose? |
A23 |
Poor current return paths in ground planes, for example when a ground plane is not continuous under the signal path. / Unbalanced signal traces / Un-terminated high impedance signals etc |
Q24 |
What if I have an intentionally high impedance signal? |
A24 |
You must be aware that EMPulse will probably affect the signal. You will have to ensure your design sufficiently screens this signal from external voltage fields to meet CE regulations |
Q25 |
Will EMPulse give me false alarms? |
A25 |
Possibly, but It is much better to be aware of EMI issues early in the design stage. By making the initial circuitry robust to EMI issues, both safety and reliability can be improved |
Q26 |
Should I only scan the area where the ES discharge occurred when looking for the cause of the problem? |
A26 |
No. ESD related problems can also be caused by the magnetic fields generated when the high ESD currents flow through conductive parts of an enclosure. These may not be local to the ESD spark. |
Q27 |
Can I do quick checks on circuitry to assess improvements in the design? |
A27 |
Yes. Because there are no connections required between EMPulse and the circuitry under test, EMPulse is very quick to use and it provides consistent results |
Q28 |
Why is the EMPulse probe such an odd shape? |
A28 |
To make fault location easy! The long edges can induce a field over a wide area of circuitry allowing a rapid sweep, the short edge at the tip allows a smaller area to be located, and the tip focuses the field even more. |
Q29 |
Can I check equipment that is still in its enclosure? |
A29 |
Yes, Precise fault finding can be done by getting down to PCB level in both small and large equipment. |
Q30 |
Can I check large equipment enclosures for susceptibility to ESD and RF fields? |
A31 |
Yes, EMPulse allows individual circuitry and wiring inside the cabinet to be assessed for immunity, thus giving an idea of the overall immunity. |
Q32 |
Can I use EMPulse to check transformer shielding? |
A32 |
Yes. Transformers use magnetic field as their transfer medium and so are always sensitive to external magnetic fields and in some cases this can cause problems. Audio transformers are often magnetically screened. This prevents 'hums' and 'buzzes' being picked up. By scanning EMPulse around the transformer with the 'FREQUENCY' control set to 1 KHz a tone may be heard from a poorly shielded audio transformer. Light dimmers and isolated control mechanisms also use transformers (although not always screened) in this case EMPulse may cause a light dimmer to flicker, or a control to malfunction indicating a problem could be lurking. |
Q33 |
Can I test the effectiveness of magnetic screening? |
A33 |
Yes. By using your oscilloscope with EMPulse and the EMCheck probe set to magnetic, a measurement is then taken. The shielding is placed between the two probes for a further measurement and the then the relative strengths can be compared |
Q34 |
I have a problem with my new design, ESD is causing spurious effects on my processor, can I use EMPulse to locate the cause of this? |
A34 |
Yes, because EMPulse is used in the very near field, it can usually locate any issues that are revealed in the in the final EMI testing phase |
Q35 |
Is the EMPulse field strength powerful enough to fully test my circuits? |
A35 |
EMPulse field, power output and frequency spectrum are sufficient to locate most EMI issues that occur at PCB level in commercial and industrial designs. |
Q36 |
My equipment has failed the final mandatory CE ESD test, how do I locate the problem? |
A36 |
Scan the Equipment under Test using EMPulse to precisely locate electronic circuitry sensitive to electric and magnetic fields generated by high currents in conductive surfaces when ESD discharges occur. |
Q37 |
Are there ESD immunity problems that EMPulse cannot locate? |
A37 |
Problems in the equipment under test caused by internal arcing from the enclosure to internal circuits will often be so severe that the field from EMPulse will not be able to locate this type of problem, |
Q38 |
Are there any RF immunity problems in my design that EMPulse cannot locate? |
A38 |
If the final RF immunity test shows problems only when the EUT is exposed to fields above 500 MHz then the field generated by EMPulse may not expose the problem. However, a lot of very high frequency problems also have symptoms at lower frequencies. |
Q39 |
Is there an On/Off switch on EMPulse? |
A39 |
No. EMPulse auto power On/Off feature ensures the instrument is always instantly ready for use |
Q40 |
What happens when the EMPulse rechargeable batteries are exhausted? |
A40 |
EMPulse will sustain the same field strength until the batteries start to fail, at which point a green LED will flash several time then EMPulse will switch off. |
Q41 |
Can I charge EMPulse whilst using the instrument? |
A41 |
Yes, but it is not recommended, EMPulse electrical field return path will be affected by the changer connection, giving inconsistent results. Note that after 1 minute of inactivity EMPulse will enter charge mode until the batteries are fully charged. |
Q42 |
How long do the batteries last? |
A42 |
EMPulse operates continuously for many hours on one charge of it internal batteries, this equates to several days of testing. |
Q43 |
Can I ‘top up’ the battery charge in EMPulse? |
A43 |
Yes, the internal intelligent battery charger will not overcharge the batteries. |
Q44 |
Is EMPulse cost effective? |
A44 |
Yes, if EMPulse can save you just one failure at the final EMC tests then it has justified its cost. It will also give improved confidence in future designs as to the Electro Magnetic Immunity of your products. EMPulse is an affordable option for pre compliance testing, allowing every electronic engineer to have one at hand to expose potential issues. |
Q45 |
Why do Electronic Engineers need EMPulse? |
A45 |
EMPulse enables an electronic design engineer to regularly check his new designs to reduce the chance of a future problems occurring, where they can be costly to rectify. Most electronic engineers have encountered EMI problems and will be pleased to be able to identify them early in the design. |