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2
votes
1answer
39 views

Switch in Circuits

I am really confused about what happens to the circuit when the switch is open or closed. What does t=0 , t=0+ , t=0- , t<0 and t >0+ mean ? what does it mean if the switch has been in ...
1
vote
1answer
27 views

Need help understanding the concept of “Circuit model of a discharging RL circuit”

I don't understand the statements for t<0 and t>0. Why does this happen?
1
vote
1answer
69 views

time it takes for the voltage to achieve 7 V

C1 = 56uF C2 = 12uF R = 12kohm E = 13 V I have this circuit and I want help to find out how long in takes for the voltage Uc2 to achieve the value 7 V? I have calculated the time constant to 117 ...
3
votes
4answers
503 views

Why are my reed relays releasing 10x faster than spec?

I have Magnecraft W171DIP-25 reed relays (datasheet). They are DPST relays with a built-in coil suppressor (according to datasheet). Their listed response time is 1 ms, and, following the logic of ...
0
votes
1answer
52 views

I have this timer circuit. Push and release vs push and hold give me different times

I have a timer circuit which I slightly modified from the one in this link I have an image below of what my circuit looks like. My problem is this: When I push my start button and immediately let ...
0
votes
0answers
39 views

Relay turn off delay

I need help with my project. I want to design a circuit for my car. It goes like this: Blinker on car is made with 1-filament bulb. I want to use this bulb as indicator and as DRL (made by PWM - ...
0
votes
0answers
36 views

Receiver wake up time

I want to make an extremely power efficient node that can receive a signal and determine what to do with the information it received. Since receiving requires a lot of power, I want to occassionally ...
-1
votes
2answers
155 views

Could a computer technically run without time measurement?

I just asked myself if a computer could technically run without time measurement? With time measurement I mean the human-invented method to measure season and day/night cycles: a year has 365 ...
3
votes
1answer
83 views

VHDL: How to change the resolution of time printed using “now” in VHDL to file or terminal

The "now" is usually used if one wants to print simulation time to screen or into a file. I need to print simulation time in ms into a file. However, using now with writeline into a file is giving me ...
3
votes
2answers
62 views

DS1307 timekeeping date significance (leap seconds?)

As part as a hobby project I built a relatively simple BCD binary LED clock using a PIC micro controller and a DS1307 RTC. Upon battery power loss the DS1307 resets back to 01/01/00 00:00:00 which ...
5
votes
2answers
239 views

ADC acquisition time

I need to take one sample of a fast changing signal at exact time with high precision. Slow sample rate ADC's have better accuracy, but I wonder about actual aquisition time - the time at which ADC is ...
0
votes
3answers
57 views

When does an RC Transient period end?

I have struggled with this question and read many articles and watched youtube videos but to no avail. For this circuit the time constant or "Tau" is 80 micro Farads (or$$80*10^-6$$) My issue lies ...
0
votes
1answer
52 views

propagation delay (low -> high / high-> low)

i build a 2x2 bit multiplier circuit where i take a number (a1a0) and multiply it by (b1b0) . and im asked to calculate the time propagation from high to low , and from low to high for every input ...
0
votes
1answer
101 views

Fall time for integrator with a large resistor

I know how to find the Outputvoltage when the circuit is "turned on" (Input x DCgain x (1-exp(-t/a)) , a=time constant , t=time )..but.. How to calculate how fast the output voltage will go to zero ...
1
vote
1answer
106 views

Detecting fast laser pulses

I'm building a laser target with photoresistors and a 90FPS camera (which will probably become CPU bottle-necked) and when yesterday I went to shopping I just saw a barcode scanner and begun thinking: ...
0
votes
1answer
86 views

Find settling time of ADC

In an assignment, I need to find the settling Time of the ADC Input Circuit time to reach 1/4 of the LSB. The ADC has 12 bits. I also know that C=12 pF and R=10 kohm. I found a formula that i used ...
1
vote
1answer
73 views

How do I work out the time when given current in a RC circuit?

So this exam question looked straight forward, but I can't get the right answer. I'm trying to find the time, from when the switch is close,that the current will equal 2mA. I've used a few formulas ...
0
votes
1answer
102 views

Unexpected sinusoidal wave at low voltage setting on oscilloscope?

I'm fairly new to electronics in general, and I'm learning to use an oscilloscope. I have a 10X probe attached to a 1uF capacitor that is completely discharged. When I set the time interval on the ...
0
votes
1answer
56 views

Delayed Overcurrent Protection

I trying to find a solution for a problem that I have with a system I am responsible for. The system runs on radio control, the problem we had is one of the radios got stuck on transmit and blocked up ...
0
votes
1answer
168 views

Measuring time using an STM32F407VGT6 microcontroller

I'm using a custom board for charging and testing batteries. Its 'brain' is an STM32F407VGT6 microcontroller. I'm developing in Ubuntu (14.04.2 LTS), using ChibiStudio (ChibiOS/RT 3.0 development ...
0
votes
1answer
143 views

Lengthening charging time of a capacitor

Alright, so I got a circuit that charges a capacitor and I want to charge it to a fixed voltage in a longer time than than the current provided would have (as the current provided would have charged ...
1
vote
3answers
10k views

How long will this appliance run from a battery?

How long can I run a water pump which requires 12V and 50W from a 12V, 40Ah, 400A car battery? Can you explain how this was calculated?
0
votes
1answer
247 views

Proof: A strictly bandlimited signal must also be a signal of infinite time duration [duplicate]

How can I show that a bandlimited signal is also of infinite time duration? I know it has to do with Fourier transforms and convolution but I'm not sure how to actually prove it. I also know that the ...
1
vote
4answers
124 views

Getting frequency of a signal from its phase

How Can I get the real time frequency of a signal from its encoder phase angle. The encoder gives us a triangular wave from (0-2*pi). If I use derivation, I get discontinuity which provoke spikes. ...
-1
votes
6answers
3k views

How do you find the voltage across a capacitor at time t= 0 and t = infinity?

Here is a diagram of the circuit, I am confused about problems a and b. How do I go about solving these two problems? Thanks! By the way you don't have to tell me the answer, I just want to ...
0
votes
1answer
60 views

İs this system is a LTI or not ?

I have a F system and a input of this system is e x(n) = e^iπn/4 and output is y(n)=cos(πn/4) So is the F system is LTI or it would be ? I try to using addivity and Homogeneity but I cant do it
0
votes
1answer
408 views

What kind of time delay switch to choose to reverse motor for just a couple of seconds

I would like to know the following: I have a motor driving a lead screw which transports a part either up or down. When going down and something comes in the way a switch gets triggered by the ...
0
votes
1answer
529 views

Shortest time required UART- UART transfer of 32 Byte block

I need to transfer 32 Byte block UART to UART 8 clock cycles per bit 1 start bit Struct 8-E-2 8bits 1 UART char, Even Parity, 2 stop bits/ char 1 + 8 + Even parity + 2 stop bits = 11 efficiency = ...
2
votes
2answers
308 views

Do LED and photodiode rise times matter for time-of-flight (TOF) measurement?

Do I need small rise times of an LED and a photodiode/APD when considering time-of-flight measurement? Given I know rise time of both diodes I am always able to count time of flight by subtracting ...
0
votes
1answer
428 views

What's the thermal time constant/capacitance of a 1/4W resistor?

I can't find it anywhere, what is the thermal time constant or thermal capacitance of a standard discrete 1/2W resistor? A table with other resistors of different power ratings would be nice, too.
0
votes
3answers
43 views

Transient analysis of filters inside allowed band

I understand that a zone pass filter will cut off portions of the signal in the cutoff zone, and allow or amplify the frequency parts of the signal in the allowed zone. Now lets assume a signal that ...
1
vote
0answers
255 views

How to calculate average delay time of circuit having several possible transition states

Is it possible to calculate average delay for all possible states directly without calculating them individually using Xilinx or with Cadence.
0
votes
3answers
74 views

Synchronized pulse generation from wirelessly connected boards

I want two or more boards (less than 10m range) to generate a LED blink at same time, within 1 ms difference, using wireless communication. First, due to power consumption, I am thinking to use ...
0
votes
2answers
157 views

How long will it take to completely run out of power a Li-ion battery of 3.7V and 1000mAh, if the load consumes 16mA?

I'm trying to determine the exact time that run out power a Li-ion battery of 3.7V and 1000mAh. I'm using a load of 16mA. If I use the theoretical calculus: $$time=\frac{1000mAh}{16mA} = 62.5 ...
2
votes
3answers
98 views

Anyone have specific examples of how IEEE 1588 is most commonly used in industry?

I've run into the concept of IEEE 1588 synchronization over Ethernet several times, and am curious what its most common uses are and the details of why it is required. For example, I read that cell ...
2
votes
5answers
750 views

How is time of supplied real time clock module maintained without battery?

I am thinking about purchasing this RTC ( real time clock ) module. Since this particular item comes supplied without a battery, I wonder how the time is being kept running in the chip since it's ...
0
votes
1answer
455 views

Determining Pipeline Cycle Time

I'm having trouble figuring out how the longest stage of a pipeline is calculated given the following: "Your processor has a 3-stage pipeline where the delay is 26ns through the first stage, 40ns ...
7
votes
2answers
223 views

How many devices can I power?

I have a device that requires 1.21 Gigawatts over one second to fully activate. Upon activation the device is disconnected automatically. The device can accept the power at any voltage, and will ...
0
votes
1answer
98 views

Electromotive force and Faraday's law

If Faraday's law states that Emf is inversely proportional to time, how is it that we can give emf in the unit volts? I'm a second year electrical apprentice, so am I missing some sort of relationship ...
2
votes
3answers
226 views

Wirelessly get the current date and time

I know there is a wireless signal all over the US (at least) sending out the current date and time. Some clocks use it so they don't need set, just not sure what its called. Is there a module or a ...
0
votes
1answer
47 views

What determines the communication speed? is it the physical link's speed or the communication card speed?

Two IEDs (Intelligent Electronic Device),an electronic relay and a gateway, are connected with Modbus RTU protocol over RS232. In the relay's manual it states that a speed of 9200 bauds can be ...
2
votes
1answer
221 views

Arduino: Generating time critical signals with interrupts

I have some problems to fully understand how interrupts on e.g. Arduinos/AVR are used in practice. Lets assume I want to generate a time-critical signal like PWM and at the same time be able to ...
0
votes
1answer
586 views

Output voltage diagram of a 3-input OR logic gate (using diodes)

Let's say we have a 3-input OR gate (using 3 diodes and a resistor) as follows: A hypothetical input voltages diagram is the following: I want to find the output voltage diagram (voltage Vo) that ...
7
votes
4answers
4k views

Is my phone battery better / more capacitative than my laptop battery?

When we go out and look for phones, the first thing I do I always look at the battery capacity, usually 2000 mAh, 3000, up to 10000 mAh for a (external?) battery. Looking at laptop batteries, they ...
2
votes
1answer
108 views

Doppler pings from MH370 Inmarsat : how was the data processed?

Published news reports indicate Inmarsat used something similar to 'doppler shift' to analyze pings from flight MH370, concluding the plane was traveling south not north. Any normal radio receiver ...
0
votes
2answers
180 views

Random timed output circuit [closed]

I am in need of some help with a project. I am trying to build a circuit that will turn on three LEDs randomly on a 1-5second cycle. I have the basic when it comes to electronics, but get stuck on ...
0
votes
1answer
179 views

Chip to cause a delay in a pulse [closed]

I was looking to get a delay in a pulse output. Is there some IC I can use to be able to change the time of the pulse output?
0
votes
1answer
5k views

how to draw a timing diagram for a logic circuit

Hello does anybody have a guide to drawing timelines for logic circuits? For flip flops like this Basically I want to draw corresponding timeline for any circuit like this:
0
votes
1answer
550 views

Electric toothbrush charging time [closed]

I replaced my old Ni-Cd 1.2 volt sub-c battery (1500 mah) from my electric toothbrush to a new Ni-MH battery 1.2 volt sub-c (3800 mah). I looked inside the toothbrush and it look like there is no ...
2
votes
3answers
4k views

Arduino Due precision with function micros

I read on arduino.cc/en/reference/micros that I can know the number of microseconds since the Arduino began running the program. On my 16 MHz Arduino Uno board, the function has a resolution of four ...