Electronics design ideas 2019

Innovation is critical in today’s engineering world and it demands technical knowledge and the highest level of creativity. Seeing compact articles that solve design problems or display innovative ways to accomplish design tasks can help to fuel your electronics creativity.

You can find many very circuit ideas at ePanorama.net circuits page.

In addition to this links to interesting electronics design related articles worth to check out can be posted to the comments section.






  1. Tomi Engdahl says:

    Selenium rectifiers – the smelliest components ever

    You’ll still find lots of these in old equipment. Sometimes you’ll smell them too, and if one blows up while you’re working in the panel the vile smell will make you leave the area fast.

  2. Tomi Engdahl says:

    1962 “TROUBLESHOOTING TRANSISTOR CIRCUITS” Technical Training, Vintage Electronics Equipment in HD

    Vintage Electronics: 1962 Technology: “TRANSISTORS” a very high quality training film explaining the functions of transistors, circuits, testing methods and skills to be learned. Well paced, exceptionally good quality (HD) and lots of vintage equipment. Explains the differences between vacuum tube circuit testing and transistor circuit testing.

  3. Tomi Engdahl says:

    Ultralow Noise Tester: 9V Battery vs. 7805 vs. LTZ1000

  4. Tomi Engdahl says:


    Concerning opamp.power supply, is there any difference when using +-12 , 14, 15 and 17 Vdc respectively.

    Higher supply voltage= more headroom. For me +/-15vDC always.

    For audio lower voltage restricts the dynamic range / headroom. Check the op amp data sheets for devices you are using for maximum permissible rail voltage.

    I agree with Nick above. Additionally, power consumption increases with increasing voltage, as do the short circuit losses, which may overheat the chip in case of a short circuit at the output.

  5. Tomi Engdahl says:

    Simple Class A Amplifier
    A 10-W Design giving subjectively better results than class B transistor amplifiers
    by J. L. Linsley Hood, M.I.E.E.

    Class A Amplifier
    Common emitter amplifiers are the most commonly used type of amplifier as they can have a very large voltage gain

  6. Tomi Engdahl says:

    Class A MOSFET amplifier using one transistor – with schematic

    Very simple amplifier circuit. Best used on a regulated or active filter type (capacitor multiplier) supply.

  7. Tomi Engdahl says:

    Op Amps Shrug Off Automotive, Industrial, Other EMI
    Sept. 14, 2021
    These rail-to-rail CMOS op amps are specifically designed to maintain their performance in high-EMI environments.

    Along with temperature extremes, electromagnetic interference (EMI) is a pervasive issue in automotive, industrial, and even medical environments as it can stimulate noise-induced errors, disrupt circuit performance, and even induce gross malfunction. While there are techniques to attenuate EMI and mitigate its effects, these usually require addition of components such as shielding, ferrite beads, filtering, bypassing, and more, all of which raise cost and real-estate requirements as well as design and qualification uncertainty.

    Recognizing this situation, ROHM introduced its EMARMOUR series in 2017, which provides superior noise immunity by combining a vertically integrated production system with proprietary analog design technology. Components in this series are designed to prevent malfunctions due to noise and do so without the need for special EMI-mitigation measures. The goal is to simplify up-front modeling and design, and reduce debug time and time to market.

    The latest entries in this family are the BD8758xY series of rail-to-rail input/output high-speed CMOS op amps with enhanced EMI immunity. These op amps target applications requiring high-speed sensing in harsh environments, such as vehicle engine control units (ECUs) and anomaly detection systems for factory automation equipment.

  8. Tomi Engdahl says:

    A new class of logic gates offers robust characteristics, low power consumption, and the ability to run on a very wide range of supply voltages.
    Learn more: http://arw.li/6184yCmJ4
    #EDN #RFL #PowerConsumption

    RFL-class logic gates

    This Design Idea describes a new class of logic gates, which we have named resistor-FET-logic, aka “RFL.” How do we know it is new? While FET switches are common today, we have been unable to find a similar resistor-FET-logic. Further, RTL (resistor-transistor-logic) is defined today as resistor-BJT-logic. BJTs are still de rigueur when discussing transistorized designs, which would not be the case if RFL were a known concept.

    How could an entire class of logic gates be overlooked? In the 1960s, things moved quickly from RTL (1961) to DTL (1962) then TTL (1963). While RFL could have been invented from about 1960, it was curiously passed over. RFL would fit the line-up of the more familiar logic classes as follows: DL, RTL, RFL, DTL, TTL, and CMOS. It is not to be confused with NMOS logic, which typically requires two or three times as many FETs to implement an equivalent function.

    RFL offers several significant advantages over RTL, and in some cases over CMOS as well. An obvious advantage is that it consumes much less power than RTL (and with that, less space). In addition, the FET core makes it easier to design with than RTL. In addition, RFL can be customized to work with a wide range of supply voltages, input voltages, output currents, and so on.

  9. Tomi Engdahl says:

    Simplest Ever Bridging Adapter for Power Amps
    © 1999, Rod Elliott – ESP

  10. Tomi Engdahl says:

    Optimizing Power Systems for the Signal Chain (Part 1)
    Sept. 30, 2021
    Understanding the sensitivity of the signal chain to power-supply noise is necessary to avoid performance degradation of high-speed analog signal-processing devices, and that means establishing a maximum allowable ripple.

    What you’ll learn:

    How to quantify the power-supply noise sensitivity of signal-processing chain loads.
    How to calculate the maximum acceptable power-supply noise.
    Strategies to meet power-domain sensitivity with realistic power-supply noise requirements.

  11. Tomi Engdahl says:

    Bounceless switching: Aluminum foil to the rescue

    A newly designed power supply required load testing with no contact bounce allowed. The load would be first unconnected from the power supply and then it would be connected using a mercury switch to ensure bounceless load application. The problem was that we didn’t have any mercury switches on hand nor could we find any to purchase. All such switches seemed to have been discontinued by their suppliers because mercury is a hazmat item.

    This was once briefly discussed at “Bounceless Switching Without Mercury,” but we will look a little deeper into the issue as follows.

    It worked as follows: As I would SLAM the ball of foil down onto the copperclad board, the foil would collapse and not bounce. After some number of uses, the ball of foil would need to be “fluffed” out again; and when eventually that could not be done anymore, a new foil ball would be used.

    When we tested the power supplies in this way, we had to prove our point with scope photographs to show that contact bounce had not occurred. We did exactly that and our equipment was accepted.

    Bounceless Switching Without Mercury – John Dunn, Consultant, Ambertec, P.E., P.C.

  12. Tomi Engdahl says:

    PIN Photodiode – α,β,γ Radiation Sensor

    Radioactive elements emit certain amounts of energetic radiation when the nucleus of a single atom changes its composition. Atoms beyond Lead tend to lower their inner energy by reducing the number of neutrons. This can happen in different ways:

    An alpha particle (two neutrons and two proton = helium core) is emitted or
    a neutron changes into a proton by emitting a beta particle (fast electron).
    The nucleus might do a rearrangement which emits certain energy as gamma quant (photon). Also electrons in the atomic shell can get excited about that and emit a quant by relaxation.

    After every single event, the element and its atomic weight changes. The amount of energy emitted, can be measured, giving the ability to detect elements by their individual spectra.

    A Geiger counter records gamma radiation, which penetrates material easily, with a Geiger Müller tube. Even alpha radiation can penetrate a thin window to be counted. The energy distribution is often unnoticed because it would need a more precise measurement.

    PIN photodiode as radiation sensor

    In a PIN photodiode (the I stands for an intrinsic, not doped layer between the p-n junction) a larger volume is sensitive to generating free electron and hole pairs by incoming photons or in this case high energy particles. In silicon it takes 1.1 eV energy thus a 5 MeV alpha particle can produce a charge of 4.5E6 pairs or a charge of 7.22E-13 As. The photodiode forms a capacitor of about 25 pF (BPW34 Vr=3V) which then charges up to 29 mV. This gives a good separation from input noise which is given 30nV/SQRT(Hz) for LT272 JFET-OpAmp. In an operational transimpedance amplifier, the input charge is converted into a voltage pulse which can be counted easily. The high feedback resistor and its parasitic capacitance set the amplification and pulse length. With 10 MΩ and 2 pF the time constant is 20 µs. the pulse high would be 350 mV. A parasitic resistance cannot be changed. A lower resistance would increase the upper frequency limit but this is conflicting with the gain-bandwidth product of the operational amplifier – so it is a compromise.

    Photodiode in epoxy resin case

    For measuring gamma radiation, there is no special need to the diodes packaging because this type of radiation is only blocked by heavy metals. Alpha radiation instead is completely blocked by 10cm air or a piece of paper. The BPW34 is a cheap PIN photodiode with a large sensitive area. The chip is packed in transparent epoxy resin, so alpha radiation is completely shielded. Dismantling enables the radiation to reach the surface. To achieve this, a handheld milling machine grinded down just until the chip was free. Then the residual epoxy was gently polished away, to prevent damage to the chips surface. A diamond grind disc and some q-tips (cotton) where used. The bond wire is easily broken so its surrounding was left untouched

    By covering the chip with paper or aluminum, a separation of the three different types of radiation becomes visible. Alpha particles with their high energy and weight are blocked by usual paper and beta by aluminum foil. Gamma radiation with its lower energy remains unchanged at the left side. Alongside, the low energy noise floor was cut off. This histogram is in logarithmic scale as particles differ much in their frequency of occurrence per energy amount, ‘channel’:

  13. Tomi Engdahl says:

    Circuit-Breaker IC Does Just That—and Much More
    Oct. 12, 2021
    Like the IC eFuse, which adds functions and features to a classic passive overcurrent and safety device, the LTC4249 does the same for the venerable electromagnetic or thermal circuit breaker.

    The classic circuit breaker—a resettable overcurrent cutoff device—has been with us since the 1920s and is well-known for its reliable, consistent performance and a simple schematic symbol (Fig. 1). Whether the breaker is designed to be activated by current overload as detected by thermal or electromagnetic conditions (both are used), it’s tightly focused by design objective and subsequent implementation on doing one thing and doing it well. (Of course, there are other circuit- and overcurrent-protection devices beyond circuit breakers and fuses, but that’s another story.)

    But while such single-minded focus is a good thing, it also can be limiting in in terms of system-design flexibility and versatility. That’s where an electronic circuit breaker (ECB) such as Analog Devices’ LTC4249 provides additional capabilities (Fig. 2). This dual ECB offers features, functions, and flexibility not available with a conventional circuit breaker.

    Due to its relatively high voltage rating along with a 1.2-A current rating, it’s able to deliver current oversight and protection across a wide range of applications, including protection for power-amplifier arrays, industrial safety, equipment-condition monitoring, relay replacement, and load switching.

    The LTC4249 dual ECB provides independent overcurrent protection to a pair of loads. Each channel has a precision enable input, current-monitor output, and ready status output, with a single resistor to configure the ECB threshold. If an overcurrent condition is detected on either channel, the corresponding breaker disconnects the input from the load.

    Note that in some ways, the relationship between a conventional circuit breaker and the ECB is analogous to the one between a conventional fusible-link device (fuse) and an electronic fuse (eFuse). In each case, the former has a single-minded functionality but lacks flexibility—which can be good or bad, depending on your perspective—while the latter is more complicated but brings added features, functions, and options to the designer and circuit approach.

  14. Tomi Engdahl says:

    Optimizing Power Systems for the Signal Chain (Part 1)
    Sept. 30, 2021
    Understanding the sensitivity of the signal chain to power-supply noise is necessary to avoid performance degradation of high-speed analog signal-processing devices, and that means establishing a maximum allowable ripple.

    Optimizing Power Systems for the Signal Chain (Part 2)
    Oct. 14, 2021
    Part 2 of the series focuses on the details involved the optimization of power distribution networks for high-speed data converters.

  15. Tomi Engdahl says:

    EMI Mitigation on NASA Spacecraft
    Oct. 19, 2021
    NASA is ramping up efforts in space travel with the Mars Perseverance Rover, the Artemis program, and ultimately humans landing on Mars. This article will delve into a possible concern in space travel that’s not often mentioned: EMI in spacecraft.

  16. Tomi Engdahl says:

    Safety Capacitors First: Class-X and Class-Y Capacitors

    Learn about Class-X and Class-Y capacitors, where they are used, and why they are referred to as “safety” capacitors

  17. Tomi Engdahl says:

    Wireless Relay Controller Circuit Diagram

  18. Tomi Engdahl says:

    Is A Diode A Switch?

    Many hardware people around these parts will be familiar with devices used as switches, using at least three-terminals to effect this, an input, an output and a gate. Typical devices that spring to mind are bipolar transistors, triacs and and ye olde triode valve. Can you use a diode to switch a signal even if it has only two terminals? Of course you can, and it’s a tried and trusted technique very common in test equipment and circuits that handle RF signals. (Video, embedded below.)

    The trick is that diodes block current in one direction but allow it to flow in the other, denoted by the deliberately obvious symbol. So your DC signals can’t swim upstream, but the same isn’t true for AC. Signals can be passed “the wrong way” through a diode by inducing small fluctuations in the current. Put another way, if you bias the diode into conduction, changes in the downstream voltage level result in changes in the current flowing through the diode, and the (smaller) AC signal gets through. But if you take away the bias, by turning off the DC bias voltage source, the diode switches back to non-conducting, blocking the signal. And that makes a diode a DC controlled switch for AC signals.

    #934 PIN Diode Switching

  19. Tomi Engdahl says:

    The Humble NE-2 Neon Lamp Has A New Trick

    Ah, the humble neon lamp. The familiar warm orange glow has graced the decks of many a DIY timepiece, sometimes in a purely indicating duty, and sometimes forming a memory element in place of a more conventional semiconductor device. Capable of many other tricks such as the ability to protect RF circuits from HV transients, its negative resistance operating region after it illuminates gives us usable hysteresis which can used to form a switching element and the way the pair of electrodes are arranged give it the ability to indicate whether a voltage source is AC or DC. Now, due to some recent research by [Johan Carlsson] and the team at Princeton University, the humble NE-2 tube has a new trick up its sleeve: acoustic transduction.

    The idea is not new at all, with some previous attempts at using electric discharge in a gas to detect audio, going back to the early part of last century, but those attempts either used atmospheric pressure air or other non-sealed devices that exhibited quite a lot of electrical noise as well as producing noxious gases. Not ideal.

    The new work concentrates on the idea of detecting the ultrasonic emissions due to initial stress relief during metal fatigue failure of large structures such as bridges and oil drilling platforms. Traditionally the only way to do this is with a piezoelectric acoustic sensor, but those are short-lived in harsh environments, annoyingly resonant in frequency response, not to mention, expensive.

    Enter the humble NE2 with its almost flat frequency response in the 200 kHz to 1 MHz region of interest, its ability to withstand operating temperatures of up to 400 degrees Celsius and being a sealed glass container, quite impervious to conditions if you can protect the connecting leads. The operating principle is simple enough, once the neon is ionised and the device is operating in the breakdown condition, pressure variations in the surrounding air are conducted through the glass, which causes pressure variations in the neon next to the electrodes. Take the current signal through the lamp and high-pass filter it, and you’ve got yourself a really cheap transducer. What a device!

    Experienced Experimenter says:
    October 24, 2021 at 9:01 pm

    They can also detect electromagnetic waves including light and terahertz radiation. They are technically simple but multi-application devices that were primarily used as indicator lights.

  20. Tomi Engdahl says:

    LED Circuit Design – How to design LED circuits

    LED Circuit Design – How to design LED circuits. How to calculate resistor size, how to protect LED, how long will a battery power a circuit, how to calculate resistor power rating, how to connect LED and much more.


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