Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [edge-detection]

18 questions
10
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1 answer

Falling edge detector sometimes doesn't work

I have a falling edge detector built based on a D flip-flop as shown in the following figure: Components: 74hc74, 74ls04n, 74hc08 A sample output is shown below (I invert the output since I need it as an active low): My question is why it…
Sina
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2
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2 answers

Weak edges over SPI data lines

I am developing a driver for an SPI temperature sensor, and having some trouble with poor quality edges near the end of packet on the data lines. While I am not experiencing any data loss, I am worried this is evidence of a larger issue; any…
stmfunk
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4 answers

Dual edge detector with binary counter doesn't count correctly

I want to build a circuit that counts the on and off of a reed switch in a CD4040 binary counter. I wired the circuit below in a breadboard. This has a debounced switch connected to a 74HC86 that when I press or release the button, output a pulse…
CBal
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1
vote
1 answer

How is clock signal edge detection done / pros and cons of different approaches?

I'm currently learning about flip-flops, and I'm curious about the different ways in which the clock signal is handled. So far I've come across 3 different techniques: AND-ing the clock signal with the inverted clock signal (relying on the gate…
Verwirrt
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0
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1 answer

Dual Edge Detector without using IC

I tried to simulate (before building it) a double edge detector circuit that I found in this post. When I simulated it, I got a decent pulse when I closed the switch but when I opened it, I got a spike more than a pulse. Is it possible to improve…
CBal
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0
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2 answers

SCLK : 50 [MHz] Rising Edge vs 25 [MHz] Dual Edge : Tradeoffs

TI manufacturers two near-identical drivers for matrixed LEDs, LP5890 and TLC6983. I was only able to determine the following differences: Characteristic LP5890 [DataSheet] TLC6983 [DataSheet] Applications • LED digital signage • Keyboard,…
kando
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2 answers

Rising and Falling edge pulse alternative

I have a requirement to generate a 4 sec pulse when a switch is closed and another pulse when the switch is open with minimal (<10uA) to zero power consumption when the pulses are not being generated. Vin is between 6.5 & 3.3v (due to battery life).…
Planestoner
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4 answers

How to detect digital edge after "long time" steady 0 or 1?

Given 1 hall sensor. It can be in: State 1: Static 0 (no oscillations) State 2: Static 1 (no oscillations) State 3: Edging 0/1 at different frequencies Given also an MCU which counts the positive edges. When there are no edges for a long time, the…
Ivy Growing
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What's a good name for change detector initialisation?

Hi I'm trying to come up with a name for when a change in input is detected and an interrupt is issued due to that. So I want to "trap" a change in an input, but a trap already means a software interrupt so it could be confusing. The name will be…
Hard Deco
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Edge detection circuit causing multiple inputs

I am trying to build a shift register using only 2 inputs - a button to enter high, and a button to enter low. Since I'm not using a separate button for the clock, I need to make an edge detection circuit so that when a user presses a button it will…
alejanndro
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How to measure rising and falling edge of square wave using c-code block

I have a problem in understanding how to incorporate a c-code block in order to measure the rising and falling edges of a square wave signal in Simulink. I am using a signal generator to generate a square wave and I need to measure the rising edge…
Pranoy Sanyal
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0
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1 answer

I designing a pulse generation circuit using capacitor and resistor but my output is not coming as expected

I am designing a pulse circuit which I will be feeding to a comparator. I am using a combination of resistor capacitor and diode for generating positive edge triggered pulse as shown in the below figure (encircled in the yellow color). I want some…
Vengatesh
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1 answer

Raspberry PI 4 Compute Wakeup Circuits

on the raspberry PI 3 computer IO boards datasheet it has on page 10 (first sheet) is has the option to connect jumper 13-14 to wake up the computer module by connecting global_en to run_pg run_pg is high when awake and low when halted and pulling…
fireblade
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3 answers

How do I build an RC-base negative edge detector, that makes a low pulse on a falling edge?

I keep coming back here searching for an RC-based negative edge detector for TTL levels, that generates a negative pulse on a falling edge. The only place I find this solution is a certain spot in a certain video by Ben Eater. But I keep forgetting…
Gunther Schadow
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LTspice and TTL logic gate parameters, my edge triggered ramp generator is current starved? How to correctly estimate TTL gate impedances?

Continuing with my edge triggered ramp generator and its simulation, thanks to all your help I have the LTspice simulation set up that I can see a theoretical circuit work that uses the rising edge of the inverted ripple-carry output (RCO) at the…
Gunther Schadow
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