Questions tagged [schmitt-trigger]
Anything related to Schmitt trigger circuits. Schmitt triggers are positive feedback comparator circuits exhibiting hysteresis.
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CPLD based Pierce oscillator
I want to make a clock generator for Altera EPM240T100C5N using the CPLD itself as a Pierce oscillator. This CPLD has Schmitt trigger inputs so I guess this should be possible. What I`m not sure about ...
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Noisy rising and falling edges at the output of a schmitt trigger circuit
I wanted to replicate a comparator circuit to PCB and I later noticed that I mistakenly swapped the inverting and non-inverting inputs. The comparator used is LM2903. Surprisingly the board was still ...
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Function generator design
So i was asked to design a function generator that eventually produces a sine wave at the output of the circuit and this is what i have come up with so far. A Schmitt trigger and then an integrator ...
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What is the purpose of the following inverter topology?
I stumbled upon an Schmitt-trigger oscillator circuit. I can fully understand the principles and its function, but what I cannot fully understand is the chain of inverters after it.
In the above ...
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Calculating resistor values for a Schmitt Trigger and LDR circuit
I am trying to make a light sensing circuit which has hysteresis.
I want an op-amp (LM358) to output logic 1 (12v) when the light level rises above 250 lux, and output logic 0 (0v) when the light ...
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Driving transistors without using MCUs
I'm trying to drive transistors with just a push of a button without using a MCU. The circuit I drawn drives different transistor on every button push and resets back. First part is a debounce circuit ...
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Really occasional malfunction of the Schmitt-trigger input
I'm using some Schmitt-trigger inputs for debouncing the interrupt problems.
Referring to above circuit, the circuit has a RC circuit and the output of the RC circuit goes to the Schmitt-trigger IC(...
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Was my circuit victim of capacitor self-resonance?
In order to generate a short pulse off a permanent constant current signal, I made this circuit.
It works well except that it created a very high frequency ripple which wreaked havoc all over the ...
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STM32L0: Fast processing of an analog sinusoidal signal
I have an embedded system based on a STM32 ARM Cortex M0+ microcontroller (STM32L051K6) and want to use it to convert an analog sinusoidal input signal into a digital pulse signal and do some SW ...
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Schmitt Trigger hysteresis
I am studying comparators and Schmitt triggers. And I did not find anywhere how to choose the value of hysteresis. I understand its purpose and I know how to calculate it. But what value is needed for ...
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Voltage appears on comparator input
I have made a pcb .
A part of the circuit is the Schmitt trigger comparator seen above .
The positive feedback resistors are chosen to give the noniverting input values from zero to 0.5 volts . ...
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Flashing an LED with Schmitt trigger
I'm trying to build the above circuit, which is supposed to flash an LED with a schmitt trigger (with the possibility to vary the frequency with the knob of the
47kOhm potentiometer). I don't have a ...
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Schmitt Trigger: Problems between theory and reality
I want to say that I am not a native English speaker so you may find some writing errors. Also, I am just learning electronics, so sorry if some questions are poorly formulated.
I am trying to build ...
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Schmitt trigger oscillators interfere with eachother (74HC14)
I am using a single 74HC14 (hex schmitt trigger) to implement three oscillators. I now have a test build ready and encounter problems. See schematic, it shows component values. Also
proper 5V power ...
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Need help understanding an electronic oscillator (Schmitt trigger + capacitor) [duplicate]
When we use this circuit, the LED blinks. I know an inverter transforms high to low voltage and low to high voltage, but here the voltage source is connected to the inverter all the time so the ...
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Simplest schmitt trigger with fewest part count for microcontroller
I own several AT89C4051 microcontrollers and I'm currently trying to read signature bytes of the micros that I probably broke (by applying 7.2V to the VCC pin before noticing the 5V regulator became a ...
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Why is this BJT Schmitt trigger producing a sine wave?
I am trying to build a Schmitt trigger from a pair of BJTs to convert a sine to a square wave.
The sine wave is from a Colpitts oscillator running at over 150 MHz. I want to measure the ...
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Determining U_ref on Schmitt Trigger
If I have only starting values a U_high=3V and U_low=2V (pulse signal on V3 on schematics), can I determine a U reference, that's given us on the inverting input of the op. amp.?
My calculations were:...
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Op. amp. with integrator - enough values to start?
All the red-circled values (Uref, C2, R31 and R36) are missing. I'm supposed to calculate them, but I think there's at least one value missing. Shouldn't Uref be known to calculate the rest of the ...
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Schmitt Trigger not reaching full saturation
I'm trying to develop a sensor based on the optoelectronic device CNY70. I want to filter the signal in order for it to be read by a microprocessor, where the threshold to change between logic levels ...
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Need help to increase schmitt trigger sensivity in a circuit
I need help on a circuit I've designed to detect hits on a piezo sensor on a drum. It uses an opamp with 2 channel, on goes to a schmitt trigger, the other to the ADC input on the XMEGA ...
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Schmitt trigger inverters or regular inverters for clean high speed data processing
I made a circuit in which data is passed in from phototransistors (part# PT334-6C) into a microcontroller (part# AT89C4051) serial port via schmitt trigger inverters (part# 74HC14) and a demultiplexer ...
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Schmitt trigger with 741 op-amp not behaving as in simulation
I am implementing a Schmitt trigger using the circuit shown below. This circuit consists of one LM741 op-amp, which acts as an asymmetrical Schmitt trigger with a single power supply. According to ...
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cd40106 Problems
so im trying to make this simple oscillator using ic cd40106 without any succsess. it's the usual astable multivibrator configuration using a 9v pwr supply, 220k resistor and a 2.2uf capacitor, the ...
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Why do I get a triangle wave in this Schmitt trigger oscillator?
I'm trying to design a function generator that can generate square, triangle and sine waves, with frequency varying between 100Hz and 100kHz.
The circuit in the blue box is supposed to be a schmitt ...
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Flip a Schmitt-Trigger when current flows through a Zener diode
I am trying to design a circuit using an intermitent power source (a bicycle hub generator), which is rectified and filtered, and regulated at 6,8V.
Now I want to "detect" when the power source is ON ...
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How does a "speed up capacitor" work in Schmitt trigger?
Hello I'm trying to understand how adding a capacitor across R2 in below circuit increases the switching speed. I don't see how C2 supplies charge to C1.
With the additional capacitor C2, it seems ...
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Analytically obtaining the hysteresis of an opamp Schmitt trigger with RC network in its inverting input
This is a follow-up from here. I have got the following Schmitt trigger circuit implemented already on a breadboard. As seen, the input signal at the non-inverting and inverting terminals of the op ...
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Strange state in input at the amplifier
I have this schematic, an invert Schmitt trigger attached to the RC component to create a triangle wave.
It's an oscillator.
The two oscillators go in to the amplifier, but I don't understand why I ...
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Comparing two variable voltages with hysteresis
All of the designs I have seen for adding hysteresis to a comparator (Schmitt triggers) assume that one of the two inputs to the comparator is set at a fixed reference voltage (typically with a ...
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Are Schmitt trigger and peak detector comparator the same?
Here is a peak detector comparator schematic ,its symbol,and its simulation.I have some question about them.
First,we all know the Schmitt trigger symbol is the same as the second picture,so are ...
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Calculating R and C for schmitt trigger debouncer
I've been looking all over the internet to try to figure out the optimal values for R1, R2, and C but couldn't find info.
I'm trying to ideally make a debouncer that will work with any button on the ...
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Can multiple Schmitt triggers in series fully debounce a switch?
After dealing with software debouncing for a while, I find it takes a huge toll on the system, so I thought of initially making a hardware debouncer with one Schmitt trigger (74HC14), a capacitor, ...
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Schmitt trigger issues... lumpy outputs and wrong switching voltages
I'm trying to implement the Schmitt trigger found in "CMOS" by J. Baker. Here's what the circuit should look like:
And this is how the transistors should be dimensioned to achieve switching voltages ...
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Inverting schmitt trigger with pnp transistors
I have a question regarding Schmitt Trigger. I am trying to design an inverting output (at UTP=Low, at LTP=High) Schmitt Trigger for an application. However, I need to use PNP transistors since the ...
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Schmitt trigger with three transistors
I usually understand well transistors circuits, but I just can't get to work with this one:
(Note the circuit is powered with +/- 12V)
It is supposed to be a schmitt trigger circuit, and I'm trying ...
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Schmitt trigger - why is there no current over the second transistor?
I'm reading through The Art of Electronics, and I'm trying to wrap my head around a Schmitt trigger.
simulate this circuit – Schematic created using CircuitLab
Why is there no current over Q2 ...
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Hardware debouncing of key matrix with minimum passive components
I have recently bought this cheap 4x4 keypad matrix. It only has the push-buttons and nothing else therefore I want to add a proper debouncing to it. The debouncing in software is something I want to ...
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Calculate transfer function H(w) of Schmitt trigger with RC at inverting input
I have got the following Schmitt trigger circuit implemented already on a breadboard. As seen, the input signal at the non-inverting and inverting terminals of the op amp is the same, but with the ...
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How to determine the saturation level when an opamp schmitt trigger starts worknig?
The Opamp inverting schmitt trigger is constructed as shown.
The output signal is:
So I ask why is the output at the start of operation saturated to positive?
Also, if the input voltage is moved ...
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Design Schmitt Trigger
Use Schmitt trigger to design a 1 kHz square wave oscillator. Assume the Op Amp supply voltages to be +15V, and the maximum bias current of the Op Amp to be 500nA. Assume that the maximum output of ...
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ADC preamp using Schmitt trigger, opamps and transistor reset
I would like to validate this design I use for input to a microcontroller for a piezo microphone trigger. I use 3 lines: a Schmitt trigger for use with an interrupt, an analog line for measuring the ...
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Sine to square wave high frequency [closed]
I have a school project that requires a sine to square wave converter for a sine wave input of 0 - 3.1 V pk from 0Hz to 500kHz. The output must be a square wave with maximum voltage 2.8V - 3.1V. So ...
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Schmitt trigger in button debouncer
While researching how to debounce a switch for digital applications, I often come around this diagram :
simulate this circuit – Schematic created using CircuitLab
Or other similar diagrams, ...
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Schmitt Trigger configuration for enabling power from guitar pickup
I would like to enable power to a regulator from a 1Vpp guitar pickup. Threshold can be between 0.2V and 1V. And I need it to disable after about 60 seconds of no signal from the pickups.
I'm ...
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Why do TTL pulse generators generate an asymmetrical square wave (unlike CMOS)?
I've read that the asymmetrical (about 1/3 mark-to-space) output waveform is due to input gate characteristics of a TTL inverter, but I want to know more about which characteristics of the TTL input ...
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Analog buffer/voltage follower with function table?
I'm looking for a buffer as I am going to fan out a VCM signal from an ADC to multiple ADC drivers.
ADC VCM out: 0.95V 10mA
ADC dr in : 10Kohm x 3
...
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Schematic review for simple LED circuit?
I'm pretty new to circuit design, I am trying to make a small board with a few LEDS that uses a toggle to turn on and another toggle to either show the LEDS always on or to blink the LEDS. I believe ...
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RC integral and differential functions, Schmitt triggers. How does this circuit work?
I'd be happy if someone explained me why this circuit is the way it is; how does it work ? Also i would like to know what the value for C1 is.
Taken from https://www.electroninvest.com/shop/items/...
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Parameter tolerance estimation with non-pure ratios
I am trying to estimate the exact tolerance of a simple circuit, consisting of an op-amp based, inverting comparator with hysteresis.
This is the schematic (electronic-tutorials.ws)
For which I ...
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