Questions tagged [trigger]

A type of oscilloscope sweep in which a *trigger*, or waveform characteristics matching a user-specified condition, will initiate the sweep. A trigger can also be an event, such as a pulse, which causes a circuit to begin performing some action.

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318 views

Relay Trigger Type Is Short

I purchased a 12v Timer Relay that has no instructions but after messing around with it I have it somewhat programmed. My issue now is using the trigger inputs, the relay information states that the ...
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2answers
566 views

Scr triggering design, shuld i use four pulses for each SCR ot two for each pair of the SCR?

I have used a TRIAC and an MOC3021 opto-coupler connected to a PIC16F887A to simulate a a full wave rectifier. I am now to design the same using an SCR h-Bridge. My question is, in order to trigger ...
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1k views

how to close the circuit by relay with a pulse and my circuit stay closed until another pulse comes

I am new in this kind of stuff so please excuse me for my lack of knowledge and English Language :) I have an old car and I want to make a circuit with an LED that lights when car is switched ...
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188 views

Does CMOS J/K trigger need pull-up resistor

I want to use J/K trigger and I was told that usually IC outputs need pull-up resistor, but if I understand it correctly the following J/K trigger is based on CMOS: TI J/K trigger And it seems to me ...
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283 views

Simultaneous electronic shutter release for multiple Lumix G7 cameras

I'm trying to trigger six Panasonic Lumix G7 cameras at once. The trigger mechanism uses a four pole 2.5 mm plug, some resistors and two switches. With no switch closed there is 41 kilohms of ...
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3k views

How to trigger triac using DC?

This video features a circuit that triggers a triac using a DC: https://www.youtube.com/watch?v=ZXXup79B6Gc I would like to make a little modification on it it. The video says that I have to connect ...
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221 views

Switching AC or DC signal via TCP/IP [closed]

What is the cheapest/easiest way to switch an AC or DC signal of at least 10 V via TCP/IP? I have 5 measurement devices which can be triggered over an 0-250 V AC/DC input (switching threshold 10 V). ...
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479 views

Triggering a relay for a set period of time when voltage drops below a certain voltage

So I need a circuit, that will trigger a relay for approx. 10 seconds when the supply voltage of the device drops below 12.5 volts. Can anyone help me out? And also what might I need to change int ...
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391 views

Help to build a circuit to trigger event only after input signal changes from “1” to “0”

I'd like to build a kind of logic as shown in the picture ,but I can't do it and I really appreciate if someone can help on that. Basically what I'd like to achieve is that when the input signal ...
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1answer
306 views

How can I cause my oscilloscope to trig on interruption of AC voltage?

I'm probing a point with 230V RMS voltage inside a machine (don't worry, I'm using a 100:1 CAT 3 probe rated at 600V), and would like to trigger my oscilloscope at the point when this signal is ...
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175 views

using TSOP4838 in anti-collision line follower

i want to use IR sensors with emitter part ( IR led ) - calibrated with an IC timer to give 38KHZ IR signal - mounted side by side - not face to face like the counter module - to the receiver part ( ...
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101 views

Manually triggering a low active pin

I have a microcontroller with an active low reset pin. This pin is connected to a timer that periodically triggers a low edge and resets the microcontroller. What would be the best circuit that would ...
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2answers
1k views

Drum trigger controller

I'm planning to make a drum controller (something like arduino) for pc using a piezo transducer as sensor, some electronic circuit, keyboard PCB connected to usb and sampler for drums in pc. I found ...
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2answers
696 views

How to view pre-trigger data on digital scope (Owon SDS-7102)

Noob oscilloscope user here. I want to view the voltage rise on my oscilloscope when I connect a device to a 1.5VDC power source, to see how clean the connection is - i.e. how many times the voltage ...
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173 views

What is the current source for in the Schmitt trigger?

What is the current source for in the schmitt trigger? I can't understand this. Can't see any resistor either.
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608 views

Why modern oscilloscopes use hardware triggering?

I've been learning how DSOs work for the past few days. As far as I understand, digital storage oscilloscopes have trigger circuitry, which usually consists of an analog comparator and a DAC. A ...
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1answer
303 views

Thyristor not switching on when 'cold'

I have breadboarded a simple circuit using a 2N6395 thyristor to drive a resistive load. In simulation all works well, and even the physical implementation works sometimes. simulate this circuit &...
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5answers
40k views

Sine wave to square wave - Schmitt trigger

I need to transform a bipolar sine wave (varies from -5 V to 5 V, 1 kHz) to a square wave for further digital processing (0 to 3.3 V), as in this image: The important thing is ...
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174 views

What can the reason be to choose this specific op-amp as a Comparator/Schmitt trigger?

A rotating instrument is outputting AC sinusoidal wave where both the frequency and amplitude of the output is proportional with the rotation speed. This output then goes to a converter box, which ...
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1answer
365 views

Level-triggered mono-stable multi-vibrator running at 12+ volts.

I need a CMOS (preferably dual) level-triggered mono-stable multi-vibrator that runs at least 12V (better at 15~18VDC), perhaps in the CD4000 family. Everything I have found is edge-triggered only or ...
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3answers
3k views

Triggering a 12 v relay with an arduino

I am trying to trigger a 12 V relay with an arduino input. All I am doing in the Arduino sketch is to make pin 13 go high and low every 1 sec (1000 ms). The relay refuses to get triggered. Can someone ...
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1k views

solenoid hammer trigger control

I am new here and a newbie regarding electronics, I shoot PCP air rifles and have a small project regarding the air rifle. The shooting mechanism is consisted of a trigger releasing a spring loaded ...
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421 views

Trigger Signal Lockout Circuit

I have been trying to design a trigger lockout circuit and I have been having some difficulties. The circuit is taking as an input a 3.3v pulse. These inputs can happen randomly and what I would ...
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846 views

How to make pulse wave from sine wave - audio frequency

I'm looking for a quick-and-dirty way of converting something close to a sine wave to a narrow pulse wave. Please see the image: a low bass note played through a broken transformer. I'm trying to re-...
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2answers
4k views

555 Timer Monostable Mode Self Triggering

I'm working on a simple project with 555 timer. I'm trying to generate a high-state output for 10s when Vcc is applied to the circuit(It is initially off). However, I have not managed to operate the ...
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373 views

Analog oscilloscope triggers

I have recently received an old 70's era Tektronix 465b dual trace oscilloscope. Unfortunately I have close to no clue how to use it. I understand the concept of triggering but this scope has two ...
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2answers
800 views

Driving 74HC logic with sub-nano second clock reference

My goal: I am trying to phase lock a 74HC-based digital circuit from a clock reference at 10~15MHz pulse repetition rate. The pulse width is around 400 picosecond. The peak voltage is sometimes below ...
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1answer
930 views

Issue getting relay to trigger, coil voltage might be insufficient

I have a simplisafe home alarm system. All components of the alarm(keypad, base station, sensors, alarm) are wireless, so there are no wires running to any sensors. I wanted to add an additional siren ...
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2answers
254 views

Altera III Cyclone FPGA input synchronization problem

I have a problem with the asynchronous input signal synchronization. I am trying to make the IIC_Slave based on Cyclone III FPGA Starter Kit. I saw 3 cases: If I do not use synchronization ...
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1answer
136 views

Disconnect circuit after primary circuit detects high volume

I would like to build a circuit that detects high volume (through a microphone or something) and when it does, it would disconnect another circuit from its power source. I don't know exactly how high ...
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4answers
9k views

Turn TTL output of logic IC into output capable of driving 50 ohm devices

I want to provide front-panel trigger signals with the microcontroller inside my device. The trigger signal will be fed via a 50 ohm coax cable to another device with a 50 ohm input. A direct ...
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1answer
760 views

How to store more waveform after trigger and less before?

I have a Rigol DS1074Z and can't figure out how to lower the time the scope spends pre-sampling to open up more memory for the actual data I want to see. Here is a nice image that will hopefully ...
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3answers
258 views

Digital trigger from a weak signal

I have a coin cell battery operated device that I'd like to detect a weak pulse. The device will be able to operate down to approx. 2.5 volt, so my Vref will be in the range 2.5 to 3V. The pulse ...
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211 views

Adding trigger functionality in for FPGA in ADC capture board

I'm using the LM97600RB board from Texas Instruments to capture data signals and this board contains an ADC as well as a Virtex-5 FPGA. I'm trying to add a trigger functionality to the board using an ...
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1answer
496 views

high value resistors in optical slave trigger? Why?

In a commercial optical trigger, for triggering flash units remotely using the on camera flash, there are very high resistors two 30Mohm in series. Why such a circuit would need resistors so big? This ...
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1answer
584 views

Arduino flash trigger using laser and photodiode [closed]

I am trying to create a trigger for a high speed flash using an Arduino, a Sharp BS120 photodiode, and a laser pointer. The results i've obtained so far are inconsistent, the system seems to miss ...
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236 views

Undersampling of a non periodic pulse signal

I am starting getting familiar with electronics, consider me as a newbie.. I am facing a sampling trouble with my DAQ system. I have a non periodical pulsed signal with a separation between the pulse ...
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3answers
1k views

Control a switch with headphone output jack

So I recently finished my boombox project, but ran into a minor problem. The boombox is powered by a blue wrapped lithium ion battery and using a ta 2021 chip amp from parts express. If I plug the aux ...
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4answers
7k views

trigger alarm with relay from PC sound output

As a total beginner, I have a project of creating an alarm device for a sailing boat. The background is the following: a Mac-mini collects, by means of different computer programs, alarms from ...
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3answers
392 views

555 Timer Triggering Too Easily

I've got a 555 timer being powered by a 5v rail that is isolated from the 3v rail running a motor driver, which runs a motor. The 555 is only supposed to fire when it gets the signal from a 38khz ...
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3answers
3k views

What is oscilloscope trigger “sensitivity”?

I'm learning more about digital oscilloscopes (previously have only worked on analog), and encountered a setting for trigger sensitivity, expressed as a value like ...
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4answers
828 views

Why does my waveform start ahead of the trigger?

I am learning how to analyze SPI bus clock and data using an entry-level digital storage oscilloscope. I'm using a BK Precision 2542B to measure the output of the clock and MOSI lines from a Netduino ...
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1answer
483 views

Trigger switch using basic components

I am doing a project at a local fair which is one of those 'steady hands' games. I am adding a twist that if you touch the wire with the loop you are dragging through it once, distractions will start. ...
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5answers
27k views

Why edge triggering is preferred over level triggering?

I am trying to understand why edge triggering is preferred over level triggering. In my book it is not explained clearly. After searching online I came to know that edge triggering is insensitive to ...
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5answers
142 views

device for outputting HIGH when input have been HIGH?

I am looking for a device or circuit that outputs HIGH when a pushbutton has been pressed (if the button is pressed again it is supposed to still output HIGH), also, if possible, another pushbutton ...
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1answer
716 views

Capacitive touchscreen [duplicate]

I am doing project in which I want to perform read and write operation by using a capacitive touchscreen. What I know is I can trigger capacitive touch screen by: By using electromagnet as I heard ...
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2answers
687 views

Turning on and off car ignition - created two pulses?

I'm building a car DVR using a GoPro. The GoPro can be turned on by shorting out two pins on the gopro bus and then turned off by shorting out the same two pins. So when the car's ignition is turned ...
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4answers
115k views

What does edge triggered and level triggered mean?

I am studying 8085 microprocessor architecture and the word edge triggered and level triggered confusing me really very much. Can anyone explain me it in layman's words ? While studying the ...
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4answers
254 views

Breakaway Glass Triggering

I need to electrically "sense" when a brick is thrown through a vertically-oriented pane of breakaway glass, breaking it. My first thought was to paint a thin strip of clear conductive ink/paint/gel ...