General Q&A about the design and function of electronic systems, electric power systems and infrastructure, their theory, and tools specific to those fields. Read these guidelines before posting.
I am designing a 4-layer PCB that has both analog and digital circuitry throughout it. The analog section involves high return currents as well as ADCs sampling the voltage across sense resistors a...
Hi, I built a constant current load following the circuit from https://www.instructables.com/id/DIY-Constant-current-load/ But my op amp gets destroyed after a few minutes. The transistor or the op...
I understand that some applications require NPN-PNP pairs with identical electrical characteristics. But I would like to understand why.
Why does the Darlington or Sziklai configurations need complementary transistors? For these configurations, when should I use complementary pairs and when could I use not complementary pairs ?
This application note from Linear Technology discusses oscillations in opamp circuits and some compensation schemes. One method discussed for reducing phase shifts in the loop gain due to the RC ne...
Recently, my home suffered a partial power outage, and due to curiosity and a desire to learn more about residential AC power, I'm trying to understand how the event that took place resulted in the...
Hello. I have a grounding problem on my acquisition system. I have read many articles, app notes and whatever but still could not find a convincing solution for the topic. The acquisition system is...
Certain high voltage resistors are fairly hard to get, such as the HVR37 series from Vishay. I'm looking at redesigning a board that produces 1000V via a transformer, but I want to use parts that ...
I've accidentally burnt my dimmer with a short. It is a common dimmer with a triac/diac/pot of the simplest configuration (the triac is a BTA16). After replacing the triac, this still does not work...
I'm using a variable duty cycle square-wave oscillator to drive a half-bridge MOSFET pair like this. Upper MOSFET is P-channel type, lower MOSFET is N-channel type: - And, I think I'm getting shoo...
I am designing a PCB that has to have class 1 div 1 associated apparatus (only the outputs to the sensor) certification. Essentially, I am using a boost converter to convert the voltage from a lith...
A few decades ago, I found a digital circuit that squares a 4-bit input in an old textbook (perhaps 1970s or 1980s). (The figure below is not the original. It differs from the original in that it ...
What benefit has a differential amplifier when measuring the signal from a sensor that is remotely located such as in this example: - Why can't I use an arrangement like this: -
My step-up converter makes audible noise both with and without a load.I am almost certain it is the inductor, because when I hold my finger on it I can feel vibration and it gets quieter. Unfortuna...
I've built a non-inverting op-amp amplifier with a gain of 101 using this circuit: - My input is 10 mV DC and I expected to measure 1.01 volts at the output but I measure 0.81 volts. What has happ...
When switching a relay there should be a flyback diode. It could be just a diode or diode with resistor in series. I understand there is a difference in the speed of relay switch-off. But what is t...
When should I consider using RTOS in my application? Every microcontroller has a good number of interrupts then what is the need of it?
I've heard that a bootloader is code that runs on a microcontroller, and is used to get your application code onto the micro. How does that work? Is there anything special that needs to be done to...
If you search through the electrolytic capacitor offerings from distributors like Farnell, RS, Digikey or Mouser, you find that the maximum life-time rating is commonly quoted as 5,000 or 10,000 ho...
When writing firmware in C for a microcontroller, how can I directly access a memory location such as a hardware peripheral register, given its absolute address? Is there a way to do this safely an...
I have a signal at 10 MHz produced from a 50 Ω source. How can I match that to a 300 Ω load with low losses without using an RF transformer (space constraints)? Are there any circuits and formulas ...
I have seen pi-filters using chokes, ferrite-beads, and plain inductors as the L-element What are the main differences between them? when use one or other?
I always have a doubt that how do firmware engineers dump code into a quad flat microcontroller? For a starter kit there is already connection like USB or some SPI ,I2C headers to burn the code,als...
I can't get my CAN bus application (ISO 11898-2, classic "high speed CAN") working and I'm receiving various CAN error frames. These error frames manifest themselves as sequences of 6 bits with my ...
What is the relationship between the pole zero diagram and bode plot? Case example: a 2nd order RLC low pass filter: - $$\dfrac{V_{OUT}}{V_{IN}} = \dfrac{\frac{1}{j\omega C}}{R+j\omega L +\frac{1}...
How can I acquire electronic parts/items/modules and ensure that there is minimal risk of them being unsuitable for my project or design?
I'm trying to drive a relay according to a 5 V digital signal, using this circuit: It works for a while, but then the transistor fails. When I replace the transistor, it works for a while again, ...
If the external power supply to a device fails, and I can't get the exact model, what do I need to specify to get the right replacement? I can re-use the old supply's connector, but what about the...
