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H: can you identify this connector?
noticed this inside a old-ish Kindle. It's a cup with a single pin. Wondering what type of connector this is called and maybe who supplies it.
AI: It's a U.FL connector.
Also known as UMCC (Ultraminiature Coax Connectors). You can get them from lots of places, like Digikey. |
H: PWM vs Analog Signals
Oftentimes in EE classes we learn about AC analysis and phasors and other stuff heavily based on analog signals. I also know that many digital applications approximate analog signals using PWM. But does everything we learn regarding analog signals still apply to PWM signals? For example, I can... |
H: How to construct a 10x8 ROM using two 9x8 ROMs
I used two 9x8 ROMs and used a decoder as enable for both ROMs. Now I have two 8 channel outputs from the two 9x8 ROMs, how am I supposed to make them into a single 8 channel bus? Or is my approach wrong?
Is this question even valid? Here is the actual question our te... |
H: Help understanding circuit in Forrest Mims' Getting Started in Electronics
I've worked through Forrest Mims' Getting Started in Electronics, but cannot figure out why the below circuit (on page 92 in the fourth edition) claims that LED1 and LED2 alternate in being lit depending on the state of input IN1. From every... |
H: Are \$h_{ie}\$ and \$r_{\pi}\$ the same thing?
In my proving below, \$r_{\pi}=h_{ie}\$. Why two different symbols are created? It confuses beginner. Or, actually there are something different?
\begin{align*}
r_e &= \frac{26m}{I_E}\\\\
r_{\pi} &= \frac{26m}{I_E}(\beta+1)\\
&= \frac{26m}{I_E}\beta\\... |
H: 100 Mhz clock frequency for a 16 Mhz MCU
I would like to ask what will happen if I set, for example, 100 Mhz as a clock frequency for a MCU, which can operate at maximum speed of 16MHz. Why wont it work?
AI: If the chip is sufficiently over-designed, it might work.
These factors will conspire against it, taking phy... |
H: Pros / Cons of LM35 and Thermistor, what alternatives?
I'm wondering which benefits/downsides I have using following thermometer?
Is there something I'm overseeing? For easy temperature measuring, what would be the easiest? My Opinion is LM35, am I right? When should I use which of them?
I don't have any experience... |
H: Measuring GameBoy power consumption
I am currently developing my own homebrew GameBoy game and I would like to try some tricks to reduce power consumption (for the sake of learning).
The GameBoy has a HALT instruction that will stop the system's clock until some interrupt is fired. I would like to use it as much as... |
H: H-bridge mosfets exploding
Something odd is happening in a h-bridge design I've made.
Schematic:
The part numbers in the picture are wrong, sorry. The n-channel mosfets (the bottom 3) are all 2N7002Ps, and the P-channel mosfets are BSS84CTs. Both have >40v rating, and are logic level. Also, the +5v tag is wrong, i... |
H: How does switch interfacing work?
This is a basic question, but I don't have a background in electronics so I find it difficult to wrap my head around the concept of how current flows. I have chosen this simple example of interfacing a switch with a microcontroller:
simulate this circuit – Schematic created using ... |
H: White hairs inside a headphones cable
I have a cheap set of Phillips SHE3000 earphones with a broken wire on the plug. Since I was repairing another set of headphones, with the same problem, I bought an extra plug, just to try repairing them too.
Here's my problem - inside the cable for each channel there's not onl... |
H: Wireless Power Transfer at 50Hz
Is is possible to transmit power using magnetic resonance coupling at 50Hz? Assuming I have no constraints on the minimum distance between the primary and the secondary coil. However, the coils are to be Air Cored.
Most of the examples available use high frequencies such as 12KHz fo... |
H: How to connect PWM output from a dsPIC MCU to 12V LEDs?
How to connect PWM output from a dsPIC30F MCU channels to 12V LED diodes? 4 x PWM channels will be used. For use with following voltage:
12V 5A Power Supply
1W high-power LEDs with working current 350mA (4 banks of 1 watt LED's)
Overcurrent protection on o... |
H: ATtiny85 Breakout Board
I've made a PCB...
I'm not sure if it will work.
I've came here for some help.
I'd just like to know if there is anything obviously wrong with it.
I have attached a image of my PCB so can anyone please have a look.
I'm a complete newbie so don't go too hard on me.
AI: Your ISP connector is w... |
H: SR Flip-Flop: NOR or NAND?
I started studying flip-flops recently and I am stuck at this point:
At some video tutorials, people explain the SR flip-flop like this:
So they use NAND gates, producing a transition table like this:
| t | t+1
| S | R | Q
| 0 | 0 | INVALID
| 0 | 1 | 1
| 1 | 0 ... |
H: help solving circuit
I'm looking for help solving this circuit.
what is the value of the resitor R4, knowing the Voltage between points A and B ( Vab=0,2V).
thanks
AI: The answer is 200 ohm...
Check the image below |
H: Cascading MFB filters
I am trying to create a 4th order active band-pass filter. I am using this site, for calculations, as was once suggested by Andy aka.
I am able to get Q factor and center frequency just right for 2nd order MFB band-pass to achieve wanted filtering. However, I am unsure how to add the second st... |
H: Can I hard wire an IR remote directly into the receiver?
I have a IR remote control and a clock (which it is designed to control.) I would like to remove the IR LED from the remote and the sensor from the clock, and run a wire between the two (so the clock can be controlled from another room.) I thought this would... |
H: Peak current requirement for switching logic
Is there a way of estimating peak current requirements for sets of logic gates? This is to qualify the regulator.
I have a Gumstix Parlor board with a 1.8V regulator (MIC5247) at 150mA on it. This is available externally so I could power the 1.8V side of my interface boa... |
H: Why would Z/P cancellation with real part > 0 between the plant and the controller make the system unstable?
Can someone help me verify the claim if there is a zero pole cancellation with real part > 0 between controller Gc and plant Gp, then the system is not stable?
I can't find any literature that confirms or d... |
H: Zener voltage selection for relay?
This question is similar to Zener Diode Selection for Relay but the focus is in how to select the voltage for optimum or near optimum release time.
With the circuit below, how does one select the zener voltage ?
simulate this circuit – Schematic created using CircuitLab
I've remo... |
H: Instrumentation amplifier and op amp V+ and V- shorted internally
I have an INA2126 instrumentation amplifier and an OPA277 operation amplifier. I was trying to check if it is busted or not by using the continuity test of the analog multimeter. I'm not sure if it's the right thing though. The weird thing was when ... |
H: Minimum filament/heater voltage for Valve/Tube amplifiers
What is the minimum voltage I need to provide my tube to be able to produce some sound?
I am trying to debug my first tube amp, but I can only power it with a 11,8V supply instead of the recommended 13,3V.(PCL86)
Could it be that the triode and pentode doesn... |
H: TCP/IP stack for wifi module
I keep reading about TCP/IP stack for wifi module. I am having bit difficulty to understand that.
I am working on hobby project in IoT and need to choose wifi module for Atmega328P. I heard about CC3000 module which is very costly. So I thought I should buy raw wifi chip and use that wi... |
H: Transistor S8050 D 331 at 1MHz
Firstly let me tell you, I don't have much knowledge about the transistors in circuits.
I am having a transistor S8050 D 331, and it's connected like on the schematic below.
The problem I am having is when I apply input square wave signal above 300 KHz. The transistor is not following... |
H: Sine wave to square wave - Schmitt trigger
I need to transform a bipolar sine wave (varies from -5 V to 5 V, 1 kHz) to a square wave for further digital processing (0 to 3.3 V), as in this image:
The important thing is that this sine wave can't be distorted, so there can't be any limiting diodes at the input.
I ha... |
H: Silk-screened 'buttons' on a touch-tone phone?
I've been taking apart a recent, standard touch tone phone with the aim for automated dialing via a separate MCU with transistors activating the contacts (Smirk. An assistive technologies project designed for my grandmother, not 'robo-calling').
Removing the solder mas... |
H: Electronitc switch without common contact
As I understand it, a transistor can be schematically described as a variable resistor controlled by a tension (when it is correctly biased). That is, the resistance between emitter and collector is regulated by the difference of potential between base and emitter. However,... |
H: LED Remote, Isolating 2 channels
I previously had a simple remote that allowed me to turn the LED strips on my motorcycle on and off when parked, which then I also wired in a separate relay so that the strips turn on with the ignition switch. The remote was switched on the positive line, so it made things easy. Nev... |
H: VHDL synthesizing a module doesn't work, but simulating it does. Error: Bad synchronouse description
I am wondering why synthesizing this code doesn't work, but simulating does.
ONLY WHEN TRYING TO SYNTHESIZE I get the following error:
Signal sig_enable cannot be synthesized, bad synchronous description. The desc... |
H: How does the Roland TR-909 reset circuit work
I'm troubleshooting my Roland TR-909 drum machine, which doesn't power on anymore. All of the voltages come up fine, but the reset line stays low. My suspicion is one or more of the components of the reset circuit have failed. Edit: the trace connecting D702 and D701 is... |
H: DIY Photobooth: LED puck lights potentiometer suggestions
I'm building a Raspberry Pi powered photobooth, and want to add some lighting.
I purchased this set of led puck lights, and would love to control their intensity from the Raspberry Pi, instead of the knob on the driver. The first row in this spec sheet descr... |
H: Node voltage for simple circuit
This is probably a dumb question but I'm not sure what voltage is on this specific node. Also ignore values, they are random.
Is it considered 0V or +V3?
Then would the voltage drop of R1 be V2 or V2 - V3?
Thanks!
EDIT: FULL PROBLEM
The op amp used in an inverting amplifier exhibits... |
H: Are these resistors in parallel
There are 2 groups of resistors that look like they might be parallel, but in between them that's making me question if they actually are. The circuit looks like this:
If they are considered parallel, how would I take into account the resistor in between them?
AI: Same circuit draw... |
H: How to calculate the maximum current a AA battery can deliver for a short period of time?
I want to measure the maximum current a AA battery (full charged) can deliver for a short period of time (let's say one second)
I have in mind to do this with a multimeter :
setup multimeter to measure amps, on the highest va... |
H: Voltage Divider-like circuit with multiple sources
I'm extremely new to circuits and am having some trouble with a variation on the voltage divider problems I've been doing.
I'm trying to determine \$V_{out}\$ in the following circuit relative to some \$V_{GND}\$ that I need to determine the location of
.
I know ... |
H: CR1632 (3v) vs. Two AA's
Kind of a newbie at this, so forgive me if this is a stupid question. I've disassembled a small lifeline alert pendant transmitter that normally runs on a CR1632, can I replace it with two AA's? Are there any disadvantages? Do CR batteries last longer, have more capacity than AA's, etc.?
On... |
H: measure speed of motor using microcontroller and proximity sensor
I have to measure the speed of an induction motor sensor here I am using is proximity . now the proximity sensor will give high and low logic to controller. now I am having trouble to understand the logic .I know it's something to do with counters bu... |
H: How many device classes can a single USB composite device implement?
I'm looking to use an LPC1345 microcontroller to run a USB hub. Thanks to this question, I know that a single USB device can be used to act as multiple classes but how many?
The USB hub would have four slots, so I'd need four MSD classes implem... |
H: Checking my understanding of how hobby servo motors operate?
Can someone tell me if my understanding is correct please.
The control signal to a hobby servo motor that is connected to an arduino operates by :
In every 1 s there are fifty windows each of length 20ms.
Thus the frequency is 50 Hz right ?
Moving on,
I... |
H: Finding the schematic of a black box with unknown impedances
I'm struggling with trying to understand a piece of homework in Electrical Engineering that I'm really trying to solve on my own but now I'm basically stuck.
The assignment is to find the schematic for the black box given below:
The black box can contain... |
H: Schmitt trigger IC/circuit with thresholds set by voltages
I want to make a Schmitt trigger for a signal, X, who's thresholds are set by two voltages, A and B.
I think I'm having a brain fart. I don't think it's possible to do this with just a single comparator and some resistors, but It would be interesting to kn... |
H: Why and How does Power Plant generate Watts?
I know my question is stupid, it is stupid because I am not understanding it correctly.
I thought two of following is required to calculate watts. Voltage, Current or Resistance/(Impedance in AC) is required.
The only way to get current is when we have a load. How does p... |
H: no distortion amp circuit, max. (d(Vout)/dt )max< slew rate, why not (d(Vin)/dt)max?
I think slew rate is how fast a circuit can react to a given input. I was asked to find the frequency limit where the output would show no distortion and tried to find it by (d(Vin)/dt)max < slew rate. But my answer wasn't correct ... |
H: Need help with fundamental understanding of voltages in this circuit
Looking at the below schematic, with LED1 being a red LED (1.7V forward voltage) and LED2 being a green LED (3.2V forward voltage), I have a few questions that probably reflect lack of some fundamental principles of circuits, and I hope someone ca... |
H: How to find places to add power indicator light in simple DC circuits?
I build a lot of little hobby circuits and I usually place them inside of some kind of project box. Right now I'm working on the "Atari Punk Consol" by Forrest Mimms. It looks like this:
I tried adding an LED to this circuit coming in from the ... |
H: Can 5V be applied to 3.3V "5V tolerant" ADC inputs for indefinite durations?
Can 5V be applied to 3.3V "5V tolerant" ADC inputs for indefinite durations? I'm looking at hardware failure modes, I know the ADC value will be clamped at 3.3V.
I just would like to know if I should generally be cautious with 5V tolerance... |
H: Feeding higher voltage sine wave to Arduino interrupt pin
I want to use Arduino to count cycles from a bicycle generator. This generator has variable frequency (which I want to measure), but also variable voltage that is proportional to wheel speed, typically being above 6V.
What I want is a way to limit the voltag... |
H: How much voltage to give my IR LED?
I got a new IR led, emitting light at 850nm. It says 5v reverse voltage and 1.5 forward voltage. How many volts should I give it? I have DESTROYED three other IR LEDs because of giving them too many volts. What should I do?!
---------------------------------ADDED-------------... |
H: Inserting compile date/time into the code in XC8
I'm in the process of writing code for a real time clock, and I want to compile the code with constants for the date/time of compilation to burn onto the clock immediately upon programming.
I believe I have seen this done before, but my searches have proved fruitless... |
H: Can I use a 2N3904 transistor in place of a 2N4401 if I flip it around?
I want to do a composite video mod for a Colecovision. The mod (http://www.benheck.com/Games/Coleco/Video_Mod.htm) calls for an NPN 2N4401-ND.
The only NPN transistor I currently have is the 2N3904. However, the pins are reversed.
Could I sim... |
H: Li-Ion battery over discharge protection
I'm designing a Li-Ion battery charger circuit with a bq24702 chip. I will use it with two Li-Ion batteries connected in series. In order to protect the batteries from over discharging, I have to know, when is the battery discharged. I will use Tensai Li-Ion TR-26650LI batte... |
H: What is this process called: Analog input, with a analog output with setpoint
What is this process called:
In my example the analog input represents line current. The analog output represents voltage. this is a closed loop with a target set point. The behavior would be that when the current level of the input is be... |
H: quick charge but slow discharge of a capacitor
I'm trying to find a circuit that will quickly charge a capacitor with a load(led) in the circuit but slowly discharge it (keep the led on longer than it took to turn on). Is this possible? Does anyone have a circuit that will do this?
Thanks!
AI: Put two resistors i... |
H: Inductor for boost converter circuit
I'm using an AAT1217 for the boost converter in my circuit. The reference circuit I'm using is:
The datasheet suggests several inductors:
It suggests using these fairly large inductors, the ones that you can see the coils. My question is why aren't the normal 0402/0603/0805 SM... |
H: Convert MP3 recording of data casette to serial data
I have a retro EMCO F1P CNC machine with a matching M1 controller that comes with mini data cassettes containing the "Machine State Data" which must be fed into registers of the controller before operation.
Unfortunately my cassette is missing, but I have managed... |
H: RS232 non-inverting level shifter
I am starting a project that will end up as an RS232 wireless bridge (XBee radios) and have no idea where to find the chip I am in need of.
I'm currently in the testing phase without the radios to ensure that the MCU->RS232 will work properly but I ran into a problem. Because I go... |
H: can't get PORTB value in pic18f2550
I'm trying to send The PORTB to the serial port and receiving the data on pickit2 UART mode..
void main()
{
TRISB = 0xFF;
PORTB = 0;
UART1_Init(9600); // Initialize UART module at 9600bps
Delay_ms(100); // Wait for UART module to stabilize
while (1)
{ // Endless loop
... |
H: Question about Frequency Travel Distance
I've a question regarding the Radio Spectrum and RFID which is confusing to me.
From what i learnt about RFID; Low Frequency (125kHz) will have shorter range but UHF will have the longest range.
However from the wikipedia of 'Radio Spectrum'; Low Frequency will have highest ... |
H: Dropping 12V to 7.4V
I'm trying to power up my NXT Mindstorm Brick which needs 7.4V (at least, that's what the battery output is) with a 12V Power Adapter. I'm doing that because I want a constant supply from the socket without the need for a battery.
I have to use a 12V adapter because, at the same time, I'm using... |
H: Step-down Regulator Voltage Drop / Frying
I'm trying to implement an Exar XRP7659 on a breadboard to step 17V to 5V @ 1.5A. The regulator is rated for 18v. Now, I have the circuit wired up and initially the output voltage is 5V on the regulator but after I add load (a phone to charge via USB) the voltage drops to 3... |
H: Unable to identify the symbol in schematic
In my job I came across reading a customer schematic. I am facing trouble in identifying the marked part of the schematic, which is connected at the pins of uUSB Interface Controller.
It seems like a fuse but not very sure of the symbol, as its confidential, unfortunately ... |
H: C18 RAM c-string - Withouth copying
In my C18 compiler (PIC, PIC18F66K22)
The following code:
char *message = "Test";
Leads to an empty string.
It's because "Test" would be saved in ROM, learned that the hard way...
But I believe it's valid C to do char *message = "Test"; so C18 is not compliant with the C-standar... |
H: rasperry pi with i2c arduino leonardo
I'd like to connect a Raspberry Pi A+ with an Arduino leonardo. I'd like the rapsi to be able to upload HID sketches on the arduino.Then I'd like the arduino to run the sketch over the USB interface which is connected to a laptop for example.
Is it possible?
The i2c connection... |
H: Is this board trace repairable?
The attached picture shows the main board of my Canon S110 camera. The camera was subjected to a shock with the USB cable connected. This resulted in the connector breaking loose from the board with the obvious damage. I use the USB cable to trigger the camera.
My question is, is it ... |
H: Resistors with arduino
simulate this circuit – Schematic created using CircuitLab
I'm using Arduino Mega Pro 5V. Pins use a max of 40-50mA.
I'm connecting 3 RGB super bright 5mm LEDs. Currently wired in parallel each light with 100Ω resistor.
I'm hooking the lights up to fiber optic fabric and they just aren't li... |
H: will i damage this toy motor by running it on a higher voltage?
I have a hand held shaver that is chargeable. the socket plug for the device says
02A250V-
and the green battery inside the device looks like this:
and the back of the board:
I have an old mobile charger that outputs 5.0v
In the first image there a... |
H: AC-DC Adaptor flashes on & off
i have bought an ac-dc adaptor to power my mini-water pump.
When i give power to the pump it start & goes off immediately and it's repeating like that till i plug it off. Adaptors LED is also blinking when this happens. It's like short circuit, or maybe the pump needs more power than... |
H: Board review: is this PIC16F877 RS232+ICSP board correct/robust?
I want to make my own development board based on a PIC, to make a RS232 bootloader from scratch. It's been a while I haven't used a PIC, and it was on a ready made development board.
I've looked around on the web and designed what I think is a minima... |
H: Vector Network Analyzer - The effect of increasing the number of measurement points
Does increasing the number of measurment points make the measurement time longer?
RBW value does change the time, but does sweep bother the time of taking a single sample?
I'm looking for disadvantages of increasing the number of po... |
H: current flow to vcc
Hi, i want to build an encoder schematic using zener diode, so the input voltage from encoder can more than 5V (using zener 5.1V), if the input voltage from encoder 0V, voltage to uC is 0V, if the input voltage more than 5V (24V for example), the voltage is limited by zener and it will be 5.1V ... |
H: 5v piezo (micropump) with arduino
edit
-added pin 9 as output in setup and now HIGH/LOW code works.
-When the pump is set to LOW it turns on, when it goes HIGH it is disabled. So when I plug the arduino in, by default the pump turns on before it reads any code. Is there anyway to set a pin to HIGH (by default) so ... |
H: Is an edge coupled microstrip / stripline a differential pair or any two adjacent traces?
I got a suggested layer stack, and and it makes mention of "edge coupled offset stripline" and "edge coupled coated microstrip".
Are edge coupled traces differential pair traces or are they any adjacent signal traces ?
AI: The... |
H: Exceeding voltage ratings on microcontroller pins using series resistor
I've been designing a circuit which requires a microcontroller to read a voltage above its current VDD or below its current VSS. I've done this once or twice before by putting a large-ish resistor in series between the high voltage source and t... |
H: Switching and protecting batteries from external power supplies
my device can work from external power source as well as from two AA batteries, so voltage in this case is 3V, but external supply is 5v.
I need to protect my circuit and power supplies in case of connecting all power sources together at a time.
I have... |
H: Confused about this KVL equation (AC circuit)
I have the following circuit below, with part of the solution:
I need to find Z. I'm confused about the KVL equation below (fourth line):
If I understand correctly, they used loop analysis: with one loop around the entire circuit and one loop around the right mesh (Io)... |
H: State diagram for 2-bit parity generator
So the question I need help with is: Design a minimal moore state machine for a 2-bit parity generator that outputs ‘1’ if the number of 1s in a 2-bit sequence is odd, and outputs ‘0’ otherwise. Overlap is allowed. (Hint: this can be done with 4 states.)
Sample input: 0 1 ... |
H: # of gates in a 32 bit ripple carry adder?
# of gates in a 32 bit ripple carry adder?
I know the answer to this question is (4X32=128). But could someone please explain to me why this is the case? I don't understand how they got the 4?
FYI: the full adder implementation is the one without the use of XOR gate in th... |
H: Why do wall plug power supplies use audible switching frequencies?
Every plug-in power supply ("wall wart") I have ever used starts off silent, but eventually starts to emit high frequency switching noise. It usually happens only when the charger is on, but not charging anything. I presume it is due to the capacito... |
H: Qtouch lib on the ATXMEGA32A4U-MH
I have a project with the ATXMEGA32A4U, in which I want to use the Atmel lib Qtouch , the problem that I have is that the controller doesn't support the Qtouch Hardware, but when I saw the other uC given in the example projects, the don't support the Qtouch Hardware too. So I'm con... |
H: Polarized capacitors in voltage doubler
Consider this voltage doubler:
.
I simulated the circuit using NON-polarized capacitors and WITHOUT the transformer as in this schematic:
and the output voltage (at C1) was still doubled. I have a couple of questions about this:
Why would people want to use polarized capaci... |
H: How to protect a MAX232 from PIC programming high voltages?
This question is derived from this Board review thread, I thought it would be preferable to make it a standalone question.
I want to be able to reset a PIC remotely using the only communication port of the board, the RS232. But I also want to be able to pr... |
H: Watchdog Reset VS Power Cycle
I am working on a system with a microcontroller than controls other microcontrollers, mainly sending commands to the other micros.
I built in a Watchdog Overflow function on the 8051, which basically just puts the device in an endless loop, thus not kicking the watchdog periodically, ... |
H: How to identify solder
Recently, my headphones mic stopped working and I figured it was probably the plug (although I'm not 100% sure). So what I've set out to do is to solder a new plug on. I asked my dad and he said the house had some solder, and even the solder iron. However, there are no lables on the solder, a... |
H: Is it possible to recover from this un-soldering mistake?
I did a real mistake when un-soldering this PCB :
The metal part of the PCB was accidentally removed. Now it is impossible to solder anything at this place again: the solder material (what's the name again in english?) doesn't "glue" to the PCB anymore.
Is ... |
H: D-Flip Flop Frequency Divider - Simulates but doesn't work on protoboard
I'm having a problem that is probably trivial, but I can't seem to make any progress. Just a disclaimer, I'm an analog EE and digital design isn't my strong suite. That being said, I'm trying to build a frequency divider using discrete parts a... |
H: Which is the best way to version control Xilinx PlanAhead projects?
Actually I'm migrating some mature projects from Xilinx ISE to Xilinx PlanAhead. I need to take advantage of TCL scripting and partitioning of PlanAhead.
This ISE projects are under version control in a SubVersion repository, so I need to define th... |
H: Providing a higher voltage to a motor
I have a 9v motor but I want to give it a lot of voltage so that it can open a door lock so if I attach it to a 18 v battery source will it be alright?
Noob in electronics . Help is highly appreciated
AI: The definative answer is in the datasheet. See what it says about short ... |
H: Practicality of this LM317T PWM Voltage and Current control circuit
Ive been trying to design a LM317T power supply with a PWM (Arduino MCU etc) adjustable voltage and current limit. After various circuits, videos and tutorials i have designed the following circuit in LTspice.
I am a complete beginner in electroni... |
H: Why does pulsed DC pass through a capacitor?
The current flowing through a capacitor equals C*dV/dt, I'm aware of that. What I don't understand is the physics of the process. Why does a capacitor pass pulsed DC (0-10V for example) when charge carriers don't change their direction?
Even if I use the "water analogy"... |
H: Could you submerge any electronic device (with no applied power) and see no ill effects?
In theory, could you completely submerge an electronic device in water, let it fully dry out, apply power, and see no ill effects?
My logic: I can't see how how you wouldn't be able to do this. I understand capacitors and batte... |
H: Resistor instead of flyback diode
I was looking at the data sheet of a common 12v relay and noticed it mentioned using a resistor instead of a flyback diode for circuit protection.
On the last page for 12V models it reads;
When connecting a coil surge protection circuit to these relays, we recommend a zener diode ... |
H: Insight on analog and digital Lock-in amplifiers operation principle?
As far as my knowledge goes:
in the analog case, the discrimination of the, low S/N ratio, signal is done by (demodulation) comparing it to local oscillator with almost identical frequency and then passing it through low pass filter. So it must ... |
H: Could you program a microcontroller without a computer?
Let's say you had a rather simple and small microcontroller and had no interfacing, no computer, no debugger, compiler, or assembler. Could you write your code in assembly, convert it (manually) to machine code, and then apply power to the appropriate pins usi... |
H: Weak pull down for SPI
I am using Arduino(does not matter) and 8 x 12 bit-ADCs to read some values. I created a prototype which consists of a Shift Register(SR) and all outputs of SR are connected to individual ADC's chip-select pin. During boot, I set all output of SR as HIGH.
I select the ADC by pulling the spec... |
H: Ambient temperature vs operating temperature?
I would like to know the difference between Ambient temperature vs operating temperature?
In datasheets they specify operating temperature for IC's.
ex -25°C to +125°C, so does this mean even though the IC's generate heat and ambient temperature is 125°C it would work(w... |
H: Substitute a Li-ion Polymer Battery with AA(A)s
My headset broke a few days ago, but the circuit board still functions properly. I want to see if I can re-use it by soldering two 3.5mm female plugs to it, so I can use it with any speaker or headset. The problem is, it used this battery, I don't dare to play with th... |
H: Functions that return Enums?
In Atmel ASF I found this piece of code
enum status_code eeprom_emulator_init(void)
{
enum status_code error_code = STATUS_OK;
struct nvm_config config;
struct nvm_parameters parameters;
/* Retrieve the NVM controller configuration - enable manual page writing
* mode so that the e... |
H: Alternative ways to maintain temperature stability of silicon BJT circuits other than feedback resistors
So I've been messing with Bipolar Junction transistors lately and I'm trying to really nail the concepts of designing circuits with these things cause I want to start using them in some of my circuits and maybe ... |
H: How to get equal number of clock cycles before ISR on an AVR
While writing a time critical piece of code for an Attiny13, I figured I could use the rising edge of an input as a trigger to read in some self clocking data. However, the number of clock cycles needed to go into the interrupt routine differs depending o... |
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