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2
votes
1answer
76 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
42 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
38 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
57 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
171 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
69 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 ...
1
vote
3answers
150 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
560 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
129 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
425 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
151 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
156 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
57 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
83 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
232 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
104 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
400 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
595 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
753 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 ...
4
votes
2answers
467 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
268 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
147 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
294 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
901 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
116 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
381 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
121 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
978 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
784 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 ...
1
vote
4answers
311 views

Phase shift a data signal by about 200ns

It would be very nice to be able to insert a little "phase shift" circuit into a data line of mine to shift it by one clock - about 200ns - instead of doing it in software which will be difficult and ...