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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...
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...
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 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 ...
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 need to design a simple boost converter like this: - I want to control duty cycle from another circuit such as an MCU but, I'm unsure how to proceed. My requirements are: - Input voltage 12 vol...
My control system gets a signal representing the plant output, but that signal has a lot of noise on it. The control system goes nuts trying to react to the noise. I need to filter out the noise ...
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 understand a circuit for driving a LED found on a board I purchased. Below is the circuit driven by an I/O pin (HS2) of a small 3.3V processor. The HS2 pin is driven by the I/O wi...
What value pullup resistor should I use for a pushbutton connected to a microcontroller input? I've seen values from 1 kΩ to over 100 kΩ. Some references just say to use 10 kΩ because it's a "goo...
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...
