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2
votes
2answers
51 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
0answers
37 views

Linear time invariant system transfer function is known - calculate output signal

Here is my task: a) Calculate and sketch amplitude spectrum of u(t), b) u(t) is input signal for linear time invariant system whose transfer function H(jw) is shown. Calculate output signal uo(t) ...
0
votes
1answer
98 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.
3
votes
3answers
159 views

Time constant for RC common emitter circruit

Here is a simple circuit for common emitter. Is the time constant for charging \$C_1\$ equal to \$C_1R_2\$? It doesn't seem logical that \$R_1\$ would influence the charging of \$C_1\$, since it's ...
0
votes
3answers
33 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
31 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
63 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
67 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
58 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
278 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
115 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 ...
0
votes
0answers
43 views

Calculating most likely time delay from multiple phase-shifts

Suppose you have a reference signal, which is sinusoidal. This signal travels in a path that adds time delay and returns to be compared with the original. The result is a phase shift between the ...
6
votes
2answers
217 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
38 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 ...
0
votes
2answers
70 views

Time synchronizing a transmitter (ultrasonic sensor) and a receiver (ultrasonic receiver) using any microcontroller [closed]

I'm trying to time synchronize a transmitter (ultrasonic sensor) and a receiver (ultrasonic receiver) using any microcontroller. Once the transmitter sends signals, the timer should be started and ...
2
votes
3answers
210 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
40 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
84 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
177 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
2k 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
100 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
69 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 ...
1
vote
0answers
98 views

CTMU Time Delay Measurement Not Working - PIC24F16KA302

I'm trying to use the CTMU unit in a PIC24F16KA302 in an impedance measuring system. I'm applying a sinusoidal signal to a component and creating a voltage and current signal which I can then use to ...
0
votes
1answer
77 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
923 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
204 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
916 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 ...
9
votes
4answers
627 views

Why wavelength is not measured with a unit of time?

While learning Fourier transforms, I have this little doubt about wavelength. Why is that wavelength for a sine wave, or any other wave, is measured with a unit of distance? If it travels w.r.t. ...
0
votes
1answer
346 views

Find current flowing over an element given charge as a function of time

This should be pretty basic but I want to clarify some: I = dQ/dt, so that means that I is the derivative of q(t) right? So if I'm given q(t) = (7t^2 - 2t +3) pC and told that time is dimensionless ...
3
votes
2answers
1k views

Calculate Charge time of capacitor with current limiting power supply

If I have a 10VDC supply current limited to 1AMP to charge a capacitor through a 1 ohm resistor, what will happen and how long does it take to charge? I need a capacitor that can "eat" this power for ...
1
vote
1answer
236 views

How to measure battery charge and depletion over time

When using my various electronic devices, they always seem to know how much charge is left in the battery. They also know when the battery is completely charged. Not exactly sure how this is ...
0
votes
1answer
184 views

Time Warp - Controling an analog clock from another room

My goal is to be able to spin an analog clocks hands forwards and backwards through a controller box that I build and wire to an analog clock. To accomplish this I imaging that I need a small hobby ...
0
votes
2answers
71 views

Should I use Counter1 to record time series data?

My Atmega328 will record data from an external sensor at around 100Hz over several minutes. Communication is done through I2C requests to the sensor. I need to store the time of measurement (relative ...
0
votes
2answers
93 views

Time of charge of a battery

Given a battery with a certain capacity C (in Ah) and given a certain charging current Ich (in A), how I can calculate the charging time?
5
votes
1answer
315 views

Building a menu and scheduler for a thermostat (rotary encoder for input, LCD screen)

I'm building an advanced thermostat on an arduino with the following goals: Use a rotary encoder (with pushbutton) as the only input device Use LCD display (standard 16x2) Use a real time clock ...
0
votes
1answer
114 views

Frequency Response Help

A discrete-time linear and time-invariant (LTI) system is given by the following input-output relationship: y[n] = 2x[n] − x[n − 1], where x[n] is the input and y[n] is the output. (a) What is the ...
0
votes
3answers
555 views

Arduino Time.h - Resets on Serial Connection for Sync

I realize and understand the problem with arduino boards resetting whenever you open a serial connection as stated and answered here. However, because of that I'm trying to figure out how various ...
0
votes
1answer
983 views

Is there any Real time clock (RTC) which provides time resolution in microseconds?

I've been searching for high precision RTCs on Google but almost all RTCs like DS12C887, DS1307 provide time resolution in seconds which is ok for general use. But is there any RTC IC which can ...
11
votes
3answers
1k views

Very accurate time measurement

I'm going to measure very short times as accurately as possible. The device will get first one pulse and within 150 microseconds six more, each on their own wires. The time between first signal and ...
5
votes
2answers
530 views

How does GPS calculate time

How can a GPS device give exact timing even when the number of available satellites are zero? I'm monitoring GPS data using VisualGPS.
6
votes
4answers
321 views

Time of flight difference in hardware

I have an ultrasonic emitter, and two ultrasonic receivers. When the emitter emits a pulse, the receivers get the signal at different times. I am only interested in the difference between the two ...
4
votes
3answers
155 views

Basic electronic watch

I'm thinking about building a simple electronic watch in my spare time. Not a lot of functions, no LCD, just keeping time and displaying the time using LEDs. However, I have never created a ...
1
vote
1answer
347 views

Arduino with multiple LEDs and timers

I'm working on creating a wireless interval timer with an Arduino, is there a specific Arduino board required that can work with multiple LEDs and give me the programming capability for providing ...
0
votes
4answers
1k views

RC time constant in astable multivibrators

I'm having trouble figuring out why exactly T=0.693*R*C is used for astable multivibrators (and why 1.1*R*C is used for monostable). At first I assumed this was only used for 555 timers but the same ...
2
votes
1answer
122 views

Does this setup create time distortion?

You have an RC element. After the RC element there is a comparator. After a given time of X minutes(X * 60 = R * C), the comparator reacts. Does voltage drop lead to time distortion, provided that ...
2
votes
3answers
2k views

Bipolar stepper motor: What should the sequence timing be?

What I mean is, how long should a coil be energized before it's de-energized. Also how long should the coil stay de-energized before I power it in the reverse direction. Where can I find this timing ...
11
votes
3answers
431 views

Cheapest way to synchronise date and time for standalone system?

If you have a device connected to a network, the answer is obvious - use NTP. If you don't have a network connection, I can think of 3 ways to get the current date and time: Radio signal, i.e. WWV ...
5
votes
1answer
138 views

Issues ascertaining current x time for battery life

It is simple to calculate a continuously-on device's theoretical battery life based on the battery datasheet capacity (assuming always nominal voltage, etc.) An LED @ 20mA.. ...
11
votes
4answers
1k views

What do I need to close an electrical circuit for a certain amount of time

I need something that closes an electrical circuit for a certain amount of time when it receives an electrical pulse. In my case, two wires touch, even for a second, the device I need will supply ...
0
votes
1answer
918 views

Generating SMPTE time code signal

SMPTE signals are (one of) the signals used to synchronize video and audio recordings from multiple cameras/recorders. How does one go about generating such a signal? I have a GPS-derived clock and ...