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I would like to ask you if you could recommend me some good book(s) which would be useful for failure analysis of the components failed in field. Ideally the description of the potential failure mechanism for different component types, maybe some hints and troubleshooting and localizing the...

Hello, I would need some advice with one problem related to clock signal picking up noise. First the layout. The source of the clock signals ( actually 2 identical clocks which are complementar to each other and are selected by logic ) is gated 555 output of 22kHz by CMOS AND gate. The target...

Hello, I have been involved in modifications on the existing device using CMOS ICs with which I do not have practical experience and for this reason I would like to ask few questions. In new circuit I would have to connect the output of LM339 with CD4013B flip flop. I have found article...

Hello, Currently I am adapting some additional modul to the existing design with dual +12V and -12V supply were the +12V is no more sufficient enough to drive the 160 mA power relay I need, so I would like to use -12V and GND to energize the coil. For driving the switching component I have 12V...

Hello, I would like to ask you what is your policy of calibrating TC cable based thermocouples. Is the initial calibration done by some third party certified body and the verifying is done internaly, all check are done by certified body or everything beginning with initial calibration is done...

Hello, I would like to ask if somebody could recommend me some reference book about wiring in industrial environment ( especially low voltage switch gears and machinery ) in US and/or IEE environment. For the general rules and buildings I have NEC handbook and IEE wiring regulations book. I...

Hello, I would like to ask you what is your policy of calibrating TC cable based thermocouples. Is the initial calibration done by some third party certified body and the verifying is done internaly, all check are done by certified body or everything beginning with initial calibration is done...

Hello, I have received a task to measure the noise according ISO 3744. The is a requirement to log temperature,relative humidity and atmospheric pressure, there are also given intervals of measurement validity ( 975 hPa - 1025 hPa for pressure and 3C-27C for ambient ). However there is not...

Hello, I am solving now a problem how to regulate down mains phase voltage in 3 phase system from 230VAC to 170 VAC. My first idea was to use transformer with one part with fixed ratio + in secondary connection of various secondaries in series. The problem is the huge variation of currents in...

Hello, I have done some measurement of case temperature of 500A SCR comparing on thermocouple placed in the hole drilled inside the case and one attached on the case. The probes were J-type soldered to cable lug attached to case with superglue ( it was told to me the usage of some pad is best...

Hello, I would like to ask you what is your experience with measuring of power coils ( nominal current few hundred amps ) with ferrite core using standard RLC bridge. My colleague claims that the results will be not usable, but my assumption is that if the measuring device works with the...

Hello, I would like to ask if somebody know some good resources or studies on the minimum bending radius of the cables particulary the flat cables. I have seen some radius vs. isolation thickness and core type tables ( probably empiric ), but I would like read something more detailed. The name...

Hi, I would like to ask what is the threshold surface temperature of electrical devices from which the application of "HOT SURFACE" warning sticker is mandatory and which standard(s) could be applied ?

Hello, I would like to ask you if the non homogeneous area with bids is normal in ferrite core manufacturing or it is a manufacturing defect: http://www.box.net/shared/joea7pjmh9. We have and issue of increased noise generation with this type of core from a certain supplier and I am curious...

Hello, I would like to know if I could get somewhere some kind of stickers, which I could use as an alternative to spray color with defined emissivity to measure copper and aluminum surface temperatures with pyrometer.

Hello, We are recently using AutoCAD 2000 for schematic capture. I would like to implement the using of more advanced program with an automatic wire numbering and cross reference creation. My tip should be something like "Electrical Designer" program, but they do not sell the program anymore...

Could somebody advice me where could I find DIN standards in English? I would be particularly interested in DIN 1052.

Could somebody help me with where could I find/purchase Chinese standards GB, GB/T, SJ, GJB in English ? Thank you for any hint.

Hello, I would like to ask you if somebody can suggest me what configuration of trap filters could handle to mitigate 5th and 11th harmonics on the mains input voltage. It seems to me that for paralleling 2 trap filters tuned to 5th and 11th harmonics of mains the 2 frequencies are not enough...

Hello, Could somebody recommend me some resources when I could find more information on different SCR firing techniques (Hard Fire, Picket Fence Firing, Trigger Pulse firing... )? I would be interested in pros, contras and typical usage as well as design considerations for pulse parameters in...