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Questions tagged [555]

The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation and oscillator applications. The part is still in widespread use, thanks to its ease of use, low price and good stability. The 556 timer is simply two 555 timers in a single package.

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I need some help with 555 timer IC in water level indicator [on hold]

I am working on a project that is water level indicator. Here's the condition: Motor turns ON after every 1 min and if water is present in the tank then it remains ON else it turns OFF after 5 sec. ...
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51 views

Oscillator Interference

a friend of mine and I have recently begun creating synthesizers and such. After testing out a standalone 555 ic oscillator on my guitar amp I found it created a lot of interference. I can easily ...
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1answer
48 views

How can I use a voltage to control the pulse width of a 555?

I have a variable PWM signal at 13.2 kHz. I want to control a servo with this signal, but the servo needs a much lower frequency, at most 80 Hz. My first idea was to use two binary counters, a NOT ...
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1answer
32 views

How to turn off 555 Timer for a period of time after Vout signal passes through

I have a single-shot 555 Timer. After triggering, output goes high for a period of time. What I would like to do now: After Vout goes high and then low again, I want to disable the 555 timer for a ...
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4answers
60 views

Multiple sensor circuits connecting to one counter and a 555 timer IC [closed]

I have to use a 555 timer in a context where I have multiple sensor circuits connecting to one counter circuit. The idea is that the counter should indicate how many activated sensor circuits are ...
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34 views

Ultrasonic proximity detector [closed]

Need help on designing an ultrasonic proximity detector, using a instrumentation amplifier, wein-bridge oscillator, 9 leds and 555 timer
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1answer
69 views

555 Astable Timer produces incorrect period/frequency

I am building a 555 astable timer circuit for a course which must match the BPM of a song. The song has a BPM of 104, which requires a timer frequency of roughly 1.733 Hz. The circuit looks as ...
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1answer
142 views

The 555 regulator that won't regulate

I made a 170V step up converter using a 555 timer for my Nixi project. At first I tried to run it using 5v but could not reach a 170v output, so I opted for a 12V supply and put in an LM7809 ...
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2answers
63 views

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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1answer
48 views

555 Timer circuit analysis

I am trying to analyse a 555 based timer circuit: My current understanding of the circuit is that the output is changed by the voltage at pins 2/6 (let's call it V). If V drops below 1/3 Vcc, output ...
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1answer
66 views

Reset circuit loops forever on-off

I've designed the following circuit: This is a "self-reset" circuit, VCC_IN es 12V from source, VCC_OUT powers the entire board, including a PIC microcontroller. The idea behind this is whenever the ...
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1answer
100 views

555 Timer IC Simulation in Eagle

I am currently designing a circuit in Autodesk Eagle which requires a 555 timer IC. The timer may be any 555 chip, such as an ne555, tlc555, or lm555, or even one of their 556 variants, but the lm555 ...
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1answer
54 views

Expected behavior of 555 timer in monostable mode

While assembling the 555 timer based circuit below I noticed that 1) the intended delay on pin 3 only works if the switch on pin 2 is closed before attaching the circuit to the 9V power supply. ...
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2answers
99 views

Using Timer 555 to obtain a frequency multiplier

How can I use a timer 555 IC to obtain a frequency multiplier? I made a frequency divider by using a timer in monostable mode but a multiplier looked difficult. Can somebody tell how can I design a ...
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1answer
82 views

Is there such 555 timer circuit?

I was wondering if there is a simple 555 Timer circuit, or even simple transistors circuit, that has a HIGH output for 1sec, 2sec, or more seconds when I trigger the input switch and will remain HIGH ...
4
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1answer
90 views

How to avoid this voltage when I turn on the circuit?

What I want to do is an Delay ON, but when I press the switch this voltage pass for a brief moment and turns the led on for a moment. How can I avoid this? Should I put the switch somewhere else? ...
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0answers
73 views

How does the capacitor charge and discharge in this configuration?

I wanted to build a metal detector using 555 timer and I found this circuit online along with a video of the working model. It says that the timer works in astable mode. But since the capacitor is not ...
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0answers
52 views

Retriggering 3V PIR sensor with 555 timer circuit and LEDS

Hi y'all I'm putting together a PIR sensor circuit that will trigger a 555 timer in monostable and run a set of LEDS for about 5 sec all on a 3v cr2032 button cell battery and than reset until next ...
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2answers
54 views

Hold Pushbutton for soft latch after X seconds

What I'm trying to achieve is have a momentary push button that must be held for say 5 seconds before latching on permanently. But the button must be held for entire duration or else timer will reset....
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3answers
145 views

PWM dimmer for off-the-shelf 12v LED bulbs

I am building a PWM dimmer for loads of up to 10 off-the-shelf 12v LED bulbs. Here is my current circuit. I'll describe a fundamental problem and I ask if I'm missing something here. The driver (...
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1answer
113 views

Keep Blowing out 2STN1550 Transistor [closed]

I'm (Trying) to build a trigger timer for an air cannon to launch ham radio antennas. This is an attempt to only allow the valve to stay open by a consistent interval to get max distance without ...
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1answer
81 views

Doubt about a NE555 [closed]

I created this circuit a few days ago, but I'm a beginner in electronics, so I do not know if it's well done This circuit causes the LED to turn on after 5 seconds and to keep it on Could someone ...
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0answers
59 views

Safety of an Inverter Circuit

I built this circuit for an EL driver/inverter I found on this website: https://dcroy.blogspot.com/2011/02/ The transistor is a TIP122 Darlington transistor and I used this transformer in the circuit....
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1answer
100 views

Astable 555 not oscillating [closed]

I've been struggling with building a 555 timer for a project. I get the expected voltage at pin 3 (output), but the problem is that it's not oscillating. The Vout is constantly 8.4V, while I expected ...
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2answers
114 views

Changing frequency of 555 timer with varicap or capacitor

I have created a 555 oscillator circuit where the output is set to have flashing LED light. Now I have a problem when I change the voltage of the potentiometer, the output frequency does not change. ...
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1answer
211 views

What all do I need for a simple speaker circuit?

I'm trying to use a 555 timer in astable mode to play a square wave sound out of a small speaker, but I'm having trouble understanding all the components I should use. I think I need something like ...
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3answers
96 views

Can I use a mosfet as a switch to power arduino?

I have a project in which I intend to use a NE555 timer to turn the arduino on/off on specific intervals. I don't want to use the ne555 output directly because of the current limitations of the chip. ...
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1answer
98 views

Why Arduino does not suit the to trigger a Spark plug but 555 timer can?

To trigger a spark plug and to control it using an Arduino, I tried following this really well-written guide. Basically, a MOSFET(IRF540N in my case) controls the closing and opening of the primary ...
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1answer
70 views

Can a 555 output be made to pull to ground?

I have design in Multisim with a 555 timer that I want to pull to ground when the signal changes. It's a missing pulse detector for resetting an mcu. Is there anyway I can achieve this with say a ...
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1answer
68 views

NE555 Circuit stops working after random time

i finished my NE555 circuit and created some pcbs. After a few attempts i could get the circuit working, and tested it successfully. I placed my circuit between a 12V 1.5Hz square wave signal and a ...
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2answers
55 views

Electronic bell for lecture [closed]

please help me about this project. I want to make electronic bell. Which duration time is like 10.45 AM to 11.45 AM ..1st lecture 11.45 AM to 12.45 PM .. 2nd lecture 12.45 PM to 1.30 PM lunch break ...
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2answers
217 views

Chicken coop door opener circuit

I'm designing a circuit that will open a chicken coop when the sun comes up. I've attached a bungee cord to the door which opens the door when a pin is released. This pin is released by a car door ...
2
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2answers
130 views

Can someone explain how this circuit works? I have an idea but I dont know if its correct

What circuit does is turns the lights on sequentialy like on this gif. What I think is happening is that the capacitor thats connected between ground and the output pin through that 4k7 res is slowly ...
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4answers
2k views

Is there a small (6-pin) DIP I can use to generate multi-MHz squarewave clocks with an external crystal?

I'm building a circuit that I'd like to run at 8 MHz to begin with, but I want to be able to try it out at 10, 12, 16, 20, and, maybe, 25 MHz. I know that many microcontrollers have the ability to ...
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0answers
61 views

555 Timer Circuit Simulation Generates an Error

I simulated the circuit below: The expected output is a 50% duty cycle 40 kHz square wave but the simulator (MultiSim) generates an error and doesn't compile. The error message is as follows: "A ...
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0answers
43 views

Can you suggest a latch circuit that ignores short duration triggers?

I am looking for a circuit which I can adapt to CNC machine to monitor a panel indicator LED to trigger a solenoid. Since CNC controls are a very mysterious and expensive I don't want to connect ...
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1answer
48 views

Obtaining data from parallel port without the “phantom power” problem

After making failed circuits in the past, I learned that the cause is that the parallel port was producing "phantom power" (aka powering the circuit). This is because I plugged my circuit into the ...
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1answer
96 views

555 circuit problem.. could it be broken?

I've made a circuit that's connected to a 12V+5V power source (attached a gallery. last photo is the schematic) it is simply a 555 timer that goes off whenever one of the two input pins goes high (...
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2answers
81 views

How to minimize DC brushed motor arcing noise propagation from MOSFET drain to gate?

I designed a basic on/off control circuit using 555 timer for a 3v hobby dc motor as shown in below. Without the motor connected, the output off the 555 timer is as shown below. (the mosfet drain is ...
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2answers
128 views

Very weak LED dimming with combined PWM signals using 555 timers

First of all, here's the circuit: What I'm doing here is using 2 PWM signals generated by 555 timers to control the warmth of the LEDs and the brightness. The top 555 is the brightness control and ...
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2answers
79 views

How does this TLC556 work?

I'm having trouble understanding what the upper part of an electronic metronome depicted in the below schematic does. I already asked about the lower op-amp part in another topic, but I also can't ...
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2answers
77 views

Problem with dual led flasher 555

I have this schematic: which supposedly makes the two LED flash alternatively with a period of 1.5s The thing is that the one connected through the NPN transistor flashes, but in it's "off" state, ...
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0answers
184 views

PWM and PPM using 555 timer

I get what PWM is and how it can be done using a 555 astable circuit. However I feel I don't completely get what PPM is how its circuit works. I understand the VCO circuit, but I don't see how it can ...
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1answer
123 views

H-Bridge: forward and backward dc motor with ic 555 by esp8266 gpio

Searching on web for make h-bridge to forward and backward dc motor with ic 555 by microcontroller ESP8266 GPIO (PWM), i found some helps and i did this circuit: This circuit always stay with +3.95v (...
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3answers
65 views

555 timer oscillator schematic question

I found this schematic, which in theory alternates the LEDs like in railway crossing lights. First of all I was wondering if it works, and if it does, what frequency does it have, and what would I ...
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1answer
93 views

Can we use 555 timer in automotive electronic circuit? [closed]

Can we use 555 timer IC in autmotive electronics design? If not then please suggest an IC in order to create dealy at laod side.
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1answer
64 views

555 stepper motor controller

I need to make a square wave generator to control a stepper motor driver. It needs to be controlled with a potentiometer and get an output range from 40 Hz to 4 kHz. I don't know a heck of a lot ...
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1answer
65 views

Low cost PWM sweep

I have this project where I need to try and get a PWM duty sweep starting at around 30% up to 100%. The issue I have is that we don't have anything left in the design (BOM Cost). I would normally use ...
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0answers
21 views

NE555 monostable timer circuit restart timer when trigger grounded in between [duplicate]

I had made an NE555 timer IC based delay circuit (monostable mode) which keeps output HIGH for 10 seconds when trigger pin is connected to ground momentarily. But what I want is if I ground trigger ...
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1answer
116 views

Atari Punk Console with 7400 chips?

How would I create a stepped tone generator using 7400 logic? For the first part, it's easy to have same range generator, with an additional transistor. Is there any way to make the same range a ...