Questions tagged [ne555]

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-4 votes
3 answers
101 views

Is there an IC controller/chip which outputs a signal for a brief amount of time, say less than 1 minute? [closed]

For instance, in this CD4075, when any one of the 3 inputs is 1 (say 5V), then the output is constant 1 (say 5V) as long as the input value is 1. I want a similar IC which is capable of outputting ...
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1 vote
2 answers
57 views

How to turn ON/OFF NE555 using a pushbutton switch that is already to ground?

I'm building a circuit for my motorcycle to replace a damaged indicator module. It runs off a NE555 to turn on another NE555 in astable mode to flash the bulbs. The switches on the bike are push ...
1 vote
1 answer
60 views

555 TIMER ic: TI Datasheet: not able to understand these lines

I have studying the 555 timer IC by experimenting and working out the internals. I now have a good understanding, and hence visited the application note in the datasheet, only to find this statement. ...
  • 13
0 votes
1 answer
42 views

NE555 varying PWM not working

I'm building a fan controller based on an NE555 with varying PWM. Unfortunately the fan is continuously blowing at full speed no matter the potentiometer position. I based the circuit on this ...
  • 11
1 vote
1 answer
63 views

Reset an NE555 timer at a specific point

I want to reset an NE555 timer (by pushing a button) at the point where the output signal is at the end of the high voltage as highlighted in the diagram. How can I accomplish this? Since the time ...
3 votes
3 answers
76 views

Using long button presses to vary duty cycle of 555 (instead of potentiometer)

Apologies for poor phrasing and structure, this is my first post. I am trying to learn how to implement 555 to create a PWM with variable duty cycle (for control of LED brightness) Rather than the ...
0 votes
2 answers
121 views

Disable NE555 using an external microcontroller

I am trying to hack this board (it's a 60A PWM motor speed controller): Specifically, I need to enable/disable the 555 timer in the center using an Arduino. To accomplish that, it would be sufficient ...
0 votes
0 answers
110 views

Please guide me why NE555 is burning

I use an NE555 to drive 2 n-channel MOSFETs. After working a few times, the NE555 burns. Where is the problem in my circuit?
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2 votes
2 answers
87 views

Voltage controlled 555 bistable operation

[Updated with working schematic!!!] I have a circuit which I tried to adapt from the 555 bistable configuration to have the 555 states controlled by input A and B; B always goes high before A. I am ...
-1 votes
3 answers
174 views

NE555 stable frequency vs duty cycle change

I am experimenting with NE555 trying to get it to output stable frequency as duty cycle is changed. Circuit is powered with a 9V DC supply. The schematic is attached. The R3 is here so that the charge ...
2 votes
4 answers
206 views

What is the relation between NE555 voltage doubler output voltage vs load?

Considering this circuit (NE555 voltage doubler), how can I find the formula for the relation between the value of the load resistor and the output voltage? You can see below two examples of this ...
  • 147
0 votes
0 answers
93 views

555 timer emits tone regardless of reset value

I made a microcontroller circuit on a PCB and I attached a typical timer circuit to it. The IC of the timer is an 8-pin DIP texas instruments NE555 Resistors are 5% tolerance. Output capacitor is ...
  • 1
3 votes
1 answer
279 views

High voltage +170V based on NE555 design - short circuit

I love Nixie tubes so I decided to build a Nixie clock. I am a beginner. I have one successful design that electronics SE helped me design. That PCB was based on through-hole components and an Arduino....
  • 131
1 vote
4 answers
238 views

Pulse a 555 astable oscillator every second without an additional IC

I am developing a ranging device to help people with blindness. I need to pulse a 38 kHz Infrared LED every 1 second. A 555 timer in astable mode generates the 38 kHz modulation. I'm currently using ...
0 votes
1 answer
103 views

Sequential LED turn signal

I am trying to build a 4 LED sequential turn signal using the ne555 timer module and some comparators. I am having trouble with my next steps when trying to figure out what is wrong with my design. ...
  • 31
0 votes
1 answer
143 views

Single shot delay timer using the TI NE555 IC

I am trying the implement the following circuit that was simulated on Falstad. I tried implementing it using the TI NE555 timer IC but it does not work like the one in the simulation. I want the ...
  • 111
1 vote
1 answer
111 views

MOSFET increase voltage on load is too slow

Can someone help me correct turn on N-MOSFET transistor (M1)? I want control Load using MOSFET with start delay. The delay based on RC with discharge. As a load use Monostable NE555: When the ...
  • 56
0 votes
0 answers
102 views

Dual 555 siren circuit keeps burning 555 ICs, but why?

I've found the following circuit online, which creates a siren sound from two 555 ICs. Please note: the 1ohm resistors were added because Falstad otherwise assumes that a capacitor without resistor ...
  • 13
0 votes
1 answer
133 views

Is this variable resistor not connected to ground?

I want to build the following PWM fan controller circuit: I am not sure about the connection of potentiometer. Usually one of the terminals is connected to the supply voltage and the other is ...
0 votes
1 answer
42 views

Varying duty cycle of an square signal using comparator

Recently i've been tinkering with the interrupter of my solid state tesla coil and the circuit that utilizes two ne555 timer ic,one in astable mode and another one modulating via pin 5 of the first ...
0 votes
3 answers
131 views

Restarting a 555 timer

I recently came into ownership of a (sort of) arcade machine and I'm looking for a little help to figure out if it's possible to modify it. Long story short, the coin-op uses a simple circuit composed ...
0 votes
1 answer
111 views

Can't make simple oscillator based on NE555

I apologize for a very stupid question, I'm very beginner in electronics. I wanted to make a simple oscillator based on NE555P chips I ordered from local store, but struggling to make it work. I found ...
1 vote
1 answer
154 views

Are 555 PWM circuit resistor and capacitor values independent of the voltage applied to a 555?

I am new to electronics so my question sound dumb. I am using this diagram to build a 555 timer IC PWM circuit: The above circuit operates on 9V but I have 5V. Do I need to change capacitor and ...
2 votes
2 answers
306 views

How to get a single pulse for 10 milliseconds?

I am trying to get a single pulse of 10 milliseconds on the output of my 555 timer. I following is my schematic: I am supplying 12 V for Vcc. The value of Resistor R and capacitor C is 100 ohms and ...
0 votes
1 answer
122 views

PWM regulated by a LDR , the darker it is outside, the darker are the LEDs

I'm doing a hobby project with an electronic panel. The panel is going to have some white LEDs under switches names. Since im going to use the panel at all times of the day I want the LEDs to be ...
1 vote
0 answers
349 views

How does the 555-timer AM radio work?

The 555-timer is used here as a demodulator. I don't understand how the 555-timer generates the desired signal. Shouldn't the output have the same frequency as the carrier signal? Can someone please ...
  • 91
0 votes
0 answers
63 views

Why are Switching Signals Used for DC-AC converter

I have noticed that oftentimes an NE555 timer circuit is used to generate AC switching signals, which allow a DC to AC rectifier to convert a DC voltage to AC voltage. This AC voltage can be used for ...
  • 207
0 votes
2 answers
136 views

Change LED blinking frequency depending on voltage

I'd like to make an LED blink with a varying frequency that depends on a voltage. I know about the 555's control pin, but I'd like the blinking to vary continuously, instead of switching between just ...
  • 375
2 votes
1 answer
338 views

Dual control an output with a MCU's GPIO and a capacitive touch button (TTP223)

I am a newbie in this electronic world and English is not my first language, please be sorry for any inconvenience I may create. It was a long story for me to come up with this writing, let get a bit ...
3 votes
2 answers
432 views

How to turn a Latch circuit from Press-ON/Press-OFF to Press-ON/Hold-OFF circuit and how to make it auto-off when power is first connected?

I'm building a Latching circuit using 555 IC. The schematic is as follows: The Input voltage is 12V and is used to operate the 555 IC that switches a relay coil through a transistor. When the circuit ...
1 vote
1 answer
4k views

Why does the 555 timer have a maximum frequency of 2MHz?

according to the website, the 555 timer has a maximum frequency of 2MHz. Why is it not less or more? What property of the timer makes the limit of the frequency? Website:http://groups.ist.utl.pt/lee/...
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4 votes
1 answer
277 views

What space applications use the 555 timer? [closed]

The 555 timer is considered the most famous integrated circuit of all time and is also credited with a versatile use in space travel. Hans R. Camenzind (the designer of the 555 timer) said that this ...
  • 91
0 votes
1 answer
187 views

Combining CMOS and TTL with drivers and Leds with relay driver

I need some practical advice on how to combine different component types. I designed a circuit with at the heart an up/down counter (74f269) The outputs of the counter are connect to via 330 ohm ...
  • 1
0 votes
0 answers
153 views

How does the comparator in the NE555 compare its two inputs?

This is a circuit diagram from the very detailed and helpful NE555 Wiki page. The yellow and red coloured segments are comparators, comparing Thresh and Trig to fractions of Vcc. If I know how a ...
0 votes
2 answers
78 views

Output voltage\current of 555

Im trying to understand what is the output voltage\current (pin 3) of that 555. If I get it right, when low (logic 0) AND Vcc is 5v AND output current is 8mA, the ...
0 votes
2 answers
186 views

switching off 555 timer with trigger button

I am new to working on 555 timer. I am running it in monostable mode. I am triggering it using a button on trigger pin. It works just fine. What I want is the LED connected to the out pin 3 to switch ...
1 vote
2 answers
291 views

NE555 - astable flashing alternative LED circuit

NE 555 help - astable alternate flashing LED circuit "In the circuit, the LED1 lights when the output pin has a HIGH state and LED2 lights when the output is in a LOW state." - I couldn't ...
0 votes
1 answer
65 views

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 ...
0 votes
0 answers
227 views

Circuit question for LM358 and NE555

I have made an IR proximity sensor which works fine when an LED is connected. Figure 1: This is the IR receiver and emitter part of the circuit. The white LED is connected to ground via a 270 ohm ...
0 votes
0 answers
34 views

NE555 delayed monostable timer with discharging capacitor after poweroff

I'm using the following circuit to try to simulate a button press in a speaker: This is supposed to wait 2 seconds, set the output high for ~500ms and then set it to low. The output of the ...
  • 261
3 votes
1 answer
282 views

Light bulb lights up in a fraction of time (blinks) using TRIAC-BT136 and MOC3021 (Solved)

I have several days with problems when assembling the circuit of the image (it is a light bulb that turns on when you clap). To briefly describe the operation of the circuit, when the potentiometer is ...
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4 votes
1 answer
324 views

555 startup timing issue

I'm new here, as I'm slowly drifting from mechanics and programming into more electronics stuff. The question I have, is if anyone could possibly point me in the right direction, as all of my searches ...
0 votes
0 answers
63 views

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 ...
0 votes
0 answers
97 views

why the 555 timer output is not the same as my calculation

Hi may i ask why is my calculation for the 555 timer of U2 is not the same as the simulator. U1 output signal 22064.24Hz, 92.81% duty cycle. t=1.1* R_1*C_1 t=1.1* 10k* 2.2n t=1.1* 10k*2.2n t=0.0242ms ...
2 votes
3 answers
1k views

555 timer - large inaccuracies with precision components [duplicate]

This is a problem I have been slowly chasing down. At first I was using 10% caps that caused the poor output accuracy. After changing the capacitor to a 1% I thought the problem would be fixed, but it ...
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4 votes
3 answers
366 views

How does the led fade circuit with the NE555 timer work?

I searched about this and each explanation did not make any sense,my explanation is that when the OUT pin is HIGH the transistor turns on and the capacitor charges,also the led turns on gradually ...
0 votes
2 answers
307 views

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 ...
0 votes
3 answers
136 views

555 trigger amplitude slightly too large to trigger

I have the following circuit which is designed to take a longer pulse (on the order of miliseconds) from a microcontroller (source v3 below) and use two 555 timers in cascade to output two consecutive ...
  • 819
0 votes
1 answer
75 views

AM circuit LTspice

I have to analyze the following circuit and understand its function. As far as I understand the top part is the simple phase-shift oscillator generating output sine wave at circa 145kHz. The NE555 is ...
  • 7
0 votes
3 answers
252 views

how to solve the phase shift of a ne555 timer

Why is the first pulse wave is not the same as the rest of the wave in this 555 timer? Is there any way to remove the wave before 2 ms or is there anyway to make it same as the rest in the graph.