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Usually, voltage followers are built with bipolar transistors (or with opamps if better precision is needed). In this case, the simple rule says that the transistor emitter "follows" the input vol...
I am trying to understand tunnel diodes by experimenting with them. Research tells me they can have negative resistance, and can be used to build a high frequency oscillator. Tunnel diodes are su...
I see a lot of common collector amplifiers with the output taken across an emitter resistor. What is the purpose of doing it this way instead of connecting your load directly to the emitter? I sh...
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 ...
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 ...
Is the cell voltage (at a modest charging rate) mostly determined by thermodynamics on the electrode surfaces and resistances of electrolyte and electrode particles, or there is a non-negligible ki...
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...
I'd like to use a 555 timer as carrier wave generator at ~ 50 kHz and modulate the amplitude with an external digital signal at ~ 1 kHz. The pulse width remains constant at 10us (50% duty cycle)....
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: -
In the circuit below, I am applying a $3.3Vpp$, $63kHz$, 50% Duty Cycle, PWM input signal at the gate of the mosfet and I am expecting to see a similar waveform with different amplitude at the LED...
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...
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...
A differential amplifier amplifies the difference between the two input voltages but suppresses any voltage common to the two inputs. Based on this scheme the differential amplifier is substrac...
Assume my oscilloscope is grounded, and the DUT is grounded as well (earth ground). I am using a standard 10 Mohm impedance 1:10 passive probe. So, the ground terminal of the probe is in fact con...
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 thought I understood the theory of scattering parameters, smith charts etc. until I tried a practical example. The following stupid example is supposed to be a microstrip line shunted by two 100...
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’m asking this question out of curiosity. I understand that this aspect of the CAN bus specification is what it is, and can not change.] The ACK bit in any CAN data frame is dominant. Each rece...
Here is the bootstrapping technique for opamps, as exposed in the Art of Electronics:. This technique is supposed to increase considerably the input impedance of the opamp for an AC input source (...
I've heard that input signals to digital circuits should be "de-bounced", at least sometimes. What is de-bouncing? Why is it needed? When is it needed? What is bouncing around in the first place?
Moderator Note If this site were mature, this question would be closed because it solicits opinions, or is too specific about particular models. In the interest of site activity, answers are being...
While doing some reading on RF designs I ran across this paragraph: I have never designed an RF circuit, but all the PCB trace antennas I have seen on development boards are square. For example,...
I want to include a wirelessly charged battery pack into my design. However, I am worried that the wireless charging could damage my main logic board. What considerations, apart from not having loo...
Consider this statement "A voltage source is heavily loaded",what does this mean? I mean that whether the load resistance is high or there is huge drop in source voltage at load due to internal res...
Nowadays, that I videoconference over WiFi a lot, I've started to notice some trends in WiFi quality. And it seems my connectivity decreases when my microwave oven is on (I work in the same room a...
In a lot of textbooks, filters seem to be designed around a matching source and load impedance. However, If I have a filter stage between an antenna and an LNA, wouldn't I want the load impedance(i...
I have a MAX809 with RESET pin connected to the gate of IRLML6344. I will rephrase my question. At 5 V, RESET is also 5 V and the LED lights up. But if I add the fan, RESET drops to 0 V and draws 1...
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...
I was looking at this design: It uses MC34063 as switching controller. I wanted to adapt this circuit, and I was busy trying to pick R1 value. The datasheet has following formulas: The issue I hav...
I just want to know why the Linear time-invariant(LTI) systems are a rich class in Signal Processing. Ofcourse there are different systems but still LTI is stressed a lot in academia. Is there any ...
I am really confused how the terms bit-rate are baud-rate are used in electronics. I never bothered thinking about baud-rate being different than bit-rate before. But recently, one of my teachers t...
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...
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...
In theory (I mean in my engineering curriculum) I never found a diode in a mosfet symbol but in datasheets there is a diode called as body diode in both pmos and nmos.Please explain its significan...
Why do we use open collector / open drain configurations in circuits? From one source I learned that LED controls are of two types- (1) Push pull,(2) Open Drain.Why do we use and what is actually h...
Background: I have several microcontroller based projects with custom PCB that have been in very-low-volume production, but the quantities are starting to go up. (batch sizes now ~100 and threateni...
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...
I read datasheet for PCT2075 temperature sensor and there are some contradicting data about accuracy for me. Page 21: accuracy ±1°C (Tamb = -25°C to +100°C) accuracy ±2°C (Tamb = -55°C to +125°C...
It is common to have a series resistor to limit the current trough an LED. I saw a circuit using the LED driver: stp16cpc26. but instead having the series resistor, they are in parallel. This LED...
In the past, a large number of new active building blocks have been proposed and published by many researchers all over the world. In most cases, these new building blocks were used for realizing n...
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'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...
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...
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 am looking at the datasheet of the 7508170315(link) transformer and something seems strange to me. If I connect this to a 12V supply and expose it to 10us pulse: 12V*10us/475uH = 252mA which ...
I understand that some applications require NPN-PNP pairs with identical electrical characteristics. But I would like to understand why.
Sensorless BLDC motor controller are becoming more and more popular, especially with rising of the drone industry. Being able to detect where the rotor is at 0rpm or no load seems intuitive if we ...
Which are the parameters I should looking for when picking a flyback diode to be placed across a generic coil, such as a relay? That is: a coil with plain on/off functionality, for example a 24VDC ...
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 ...
