Questions tagged [monostable]
The monostable tag has no usage guidance.
82
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How to change sync pulse into pulse signal
From this application note :
https://www.renesas.com/br/en/document/apn/cm-318-dc-power-line-communication
I want to change sync pulse into pulse to process in microcontroller
I am thinking to use ...
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Simple timed one shot trigger to enable LED with constant voltage not momentary switch
looking for some help on how to accomplish this.
What I have is a 3 way switch (off, on (position 1), on (position 2)) powered by a 12v to 13.5v DC power source (think car battery). Position 1 only ...
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2
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How does the TI CD14538BM96 behave in response to long input pulses?
This is related to my earlier question on driving dual coil latching relays from a single logic signal.
This question is on how whether the TI CD14538BM96 monostable multivibrator can be used to ...
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How do I wake an ESP8266 when a float sensor value changes?
My goal is to reset an ESP8266 in deep sleep (pull RST low) when the value of my float sensor changes (which detects the water level in a tank), so that I can report the value change to the IoT ...
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Monostable (eg CD4538 channel) connecting rise and fall inputs together to generate pulse from rise or fall
I would like to use one channel of a dual monostable (CD4538) to generate a pulse from either a rise or fall single trigger input feed.
If I connect rise and fall trigger inputs together
(or use a ...
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2
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538
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Deep sleep wake ESP8266 with DS3231 RTC alarm
I'm trying to use a DS3231 RTC to wake my ESP8266 at a specific hour, minute and second. My circuit is a very low power design.
I believe I need to reset my microcontroller (by momentarily pulling the ...
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63
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Optimizing RC values on monostable multivibrator accounting for retrigger timing
I am attempting to use a retriggerable monostable multivibrator datasheet to tell me if an engine is on or off. The input to the IC is a square wave usually between 100-200Hz 0-3.3V. The signal is ...
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Dark Green Probe in Orcad Capture/Pspice 17.4
I am running into this consistently odd behavior and I was hoping someone had some insight on what it means, my searches have been fruitless so far.
Sometimes when I try a transient analysis and try ...
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What happens if we give a negative trigger pulse before a monostable multivibrator reaches it's stable state
Monostable Multivibrator using Op Amp, from this link,
Obviously there is a certain amount of time that the capacitor takes to charge again from -Vcc*β to VD (0.7v) and therefore during this period a ...
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Monostable multivibrator edge detector not working as expected
I have the following circuit that consists of a Monostable Multi-vibrator, SN74LVC1G123 configured to detect a falling edge upon button press and outputs a logic HIGH which in turn is inverted using ...
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213
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Minimum time pulse for the NE555
I want to know if the pulse period of the monostable multivibrator using NE555 can go down to around 200ns. I don't have necessary equipment to test it and I'm afraid the timer can't work with that ...
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151
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One shot monostable multivibrator with OA, output active low
I need to make a one-shot multivibrator with a OA, since in the main design, one OA is available form a package with 4 (single supply).
Triggering can be either POS or NEG since I can adapt the ...
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171
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Why am I getting an "invalid expression" for output voltage and not for other voltages?
I have designed this monostable (one-shot) vibrator using the 555 timer, yet I am getting this type of error on Pspice for the output voltage only. Where have I gone wrong?
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555 timer monostable → simulation is not working
I would like to build a simple circuit with a 555 timer, in monostable mode (monoflop). I looked at these two diagrams for this purpose.
http://www.learningaboutelectronics.com/Articles/555-timer-...
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How to connect the output of the 555 in monostable mode to an optocoupler?
I currently have the following schematic for my circuit:
Link to the simulation.
On the simulation everything is working pretty good. The output of the 555 which is in monostable mode is giving ...
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163
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555 PWM Checker/Filter
I need to design "PWM Checker" or filter - that will check that the input signal is at specific frequency (let's say 1 kHz) and specific duty cycle (let's say 33%) and the design has to use ...
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337
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OUTPUT pin is not going LOW in 555 timer IC
I was working on a simple monostable IC project and I came acroos this problem.
When the switch is closed which triggers the pin 2 and sets pin 2 on low logic OUTPUT goes HIGH.
As per my settings of C ...
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302
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555 timer won't trigger monostable mode unless I add a switch between R12 and ground?
I have this setup which is a part of a bigger circuit to control motors.
This is supposed to be a timer in monostable mode with about a minute of hi output when triggered.
The lines going down are to ...
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314
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Usage of 555/556 Timer as a One shot timer
Im using two 555 timers / one 556 timer IC for a project. I've used it a couple of times before but never in monostable mode. Basically I need to activate a DC Motor in one direction for a set amount ...
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Toggling between astable and monostable input to dual 555 timer pulse generator
Hi there,
I am looking to build a simple analog circuit to generate adjustable pulses for a medical device. The current circuit utilises 2x LMC555 timers - one in an astable configuration to generate ...
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555 timer IC unexpected pulse wave width problem in monostable mode
I was trying to make a monostable timer for a specific project which should trigger output high for around 5 seconds. For that, I have chosen a capacitor of 4700uf and a resistor of 1K.
According to ...
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3
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How to build an arbitrary (one-shot) pulse generator?
I need a circuit/IC that can generate a single pulse with a variable pulse width (I would want a minimum of 50 ns but if that is not possible the next minimum can be 1 μs, and even if that is not ...
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My NE555 circuit triggers falsely when connected to the mains using a 5V adapter
I have designed a laser security system using an NE555 in monostable mode with a potentiometer to adjust the pulse length. Another NE555 (U2) ciruit is used for delaying power on the monostable ...
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128
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Tacho signal for LED fan monitoring
I am struggling with this problem: I have a fan whose output tacho signal is a square wave when it is running properly.
If the fan stops the signal remains at its last value (either high or low). I ...
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84
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What is equation for the 555 timer control voltage in monostable
How do i get the 555 timer in monostable output frequency when there is voltage apply at control voltage. I only able to find the formula for astable which is
Orignal post:-
What is the equation for ...
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594
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Reset and trigger 555 timer with one push button
I want to turn on a LED with a single push button. When the button is pressed, the LED has to be turned on for an X amount of time. But what I also want, is to turn of the LED with the same push ...
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241
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How does the loopback on a non-retriggerable monostable work?
I understand how to connect a monstable multivibrator to be in the non-retriggerable mode. Just loopback the /Q to the falling edge input or the Q to the rising edge output) as in the following ...
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477
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How to bypass continuous input on Trigger pin of 555 IC after some time working in Mono-Stable/ One shot version?
I configured the 555 IC such that it gives the output pulse for 3 Seconds (Approx.) as soon as there is input on trigger pin, but my project requirement is; even if there is input continuously on ...
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What is this circuit called?
This is a circuit I made to create a high signal when a switch is opened and closed. The duration of the signal can be adjusted by changing the capacitors and resistors.
It is also low powered when ...
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604
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555 timer not working in monostable mode
I am a newbie electronics learner and trying my hands on 555 timer to get it running in the monostable mode. Am trying the circuit as in the attached diagram. I am just unable to get the LED blink. I ...
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41
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Switching circuit based on clock
I have attached the timing diagram. I want something similar to monostable multivibrator but with so additional features. don't know how the circuit will be.
Case 1:
I want the output to go high at ...
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332
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Pulse output only from switch toggle on OR switch toggle off (not both)
I found this circuit here from a few years ago, posted thanks to tcrosley:
Using the 74LS122 I found that it produces a short pulse both on latching the input high AND to low. The problem is I can't ...
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How to find the exact value of K for SN54LS123
I have a circuit containing SN54LS123 (Datasheet) IC. I want to know the output pulse width but unable to figure out the value of K.
The formula is PW = K * R * C.
The values of K is given in the ...
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494
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Replacing an NE555 with a 74HC123D
I want to replace an NE555 with a 74HC123D in a battery powered device. It is used to clock a CD4017, for which I need a pulsed signal of 46Hz.
I read that a 74HC123D needs less power than a 555. How ...
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132
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Can we trigger a mono-stable multi-vibrator( using 555 IC ) using mono audio signal?
I'm working on a project where, a certain low frequency audio spike should trigger the mono-stable multi-vibrator. If we can trigger a mono-stable multi-vibrator using a mono audio signal, how much is ...
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496
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How to stretch 1ns pulse into a 5ns pulse?
We have a time-tagger device that records the arrival of a LVTTL signal with 0.5ns resolution. Currently the 5ns LVTTL signal is generated by a separate commercial Avalanche Photon Diode but I would ...
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555 Monostable delay circuit misbehaving
I have designed a basic application of a 555 in a monostable configuration to delay the LOW/off state of an output signal. (The output drives some power electronics through an optocoupler).
As per my ...
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365
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555 timer that does not output low when reset
I'm trying to design a circuit with the following goals:
When not active, output can be either Vcc or floating
When triggered by pressing a button, output pulses several times to GND at some ...
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490
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555 timer with controllable reset
I have a 555 monostable set up which is triggered when an output from another circuit goes low. This then remains on for 10 s. This all works almost perfectly.
My issue is that when the output from ...
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Trouble with engineering project - 555 timers
I'm currently finishing my GCSE engineering project and I am attempting to use a dual 555 timer circuit as a timer. I am using a schematic I copied off Kitronik Alarm Project Kit, but when simulating ...
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Can an electrolytic capacitor be charged reversed bias by a small voltage? [duplicate]
In this monostable circuit the C1 capacitor is reverse biased. When T1 is closed and C1 is discharged what will happen on the right side of C1?
Will it charge up to 0.6 volts so that T2 can be ...
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Capacitor charging voltage showing ripples on scope. Origin?
I have an RC circuit delivering a square signal via a standard 555 timer set in monostable.
I am powering the 555 with 4.88V DC directly from the Arduino, which itself is taking its power from the ...
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monostable 555 timer - buzzer motor and pulsing
I need this circuit to pulse an LED while running a buzzer motor for an adjustable period
RV1 and C1 should give me 1 - 5s of pulse, while RV2 and C2 should adjust the LED ramp times
The LED will be ...
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2
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Comparison of 1G123 to 4538
I am designing the edge detection circuit with predefined output pulse duration. Pulse width will be 18.33 ms, supply power is 5V. Error tolerable is +-1 ms.
There're a number of designs already ...
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171
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IC 555 as monostable multivibrator
How is the output of a monostable multivibrator affected if the trigger pin is kept at a negative voltage (0V)?
The upper voltage reference comparator will change its output to logic 1, while the ...
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Speed of monostable circuit
I need to find the time between the rising edge of an input signal and generating a new output state. I don't have a scope so I can't measure it.
Does someone know how fast it is, and what the edges ...
user208862
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Can I use the oscillation frequency equation for this circuit?
I'm not really sure if this is a question that can be answered so I'm sorry in advance if it isn't. I've just started doing electronics on a breadboard and I'm making a "Mini Strobe Light" from Jaycar'...
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monostable Eccles - Jordan multivibrator, theory
I’ve a few problems and questions to the principle of monostable multivibrator’s work. Basic schematic is as below:
What is the reason for D1, C1, R3 elements at input? Why I can’t just tie a ...
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496
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Why is the potentiometer setup in this configuration in this 555 circuit
I just started learning about chips and signals using the book Make:
Electronics, in one of the circuits, used to generate a pulse in Monostable mode
a potentiometer is used to vary the pulse length....
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2k
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One-shot Monostable 555 with long trigger
I am building a one-shot monostable oscillator using 555 Timer. Trigger pulse is controlled by a pushbutton, and thus can be long. I don't want output pulse to stay high for that long (simulated by V2 ...
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