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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3
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2answers
70 views

CD4029 does not initialize at 0

I am attempting to build a very simple 4 bit counting machine using a CD4029 ic and a 555 timer. I have built my circuit on a breadboard and everything seems to be working perfectly, however on the ...
0
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0answers
33 views

Magnetic Polarity Detection Sensor

I'm interested in figuring out the best approach to determine the polarity of a magnet. I've started thinking through how to build a simple circuit to detect North vs South and indicate via a one ...
0
votes
1answer
97 views

How to build a blinking 12V indicator LED light

I attempt to build a blinking circuit using 12V truck light ( like this one: http://www.princessauto.com/pal/en/Tail-Lights/4-in-LED-Stop-Turn-Tail-Light/8126047.p). I have try to build a single LED ...
0
votes
0answers
54 views

How to combine a 555 timer and an MC34063

So, I've been at a project for a couple of weeks now, far too long in my opinion. I'm coming down to the final push and my last obstacle is to connect two circuits together to make a Piezo transducer ...
-1
votes
2answers
50 views

555 delayed after threshold goes above control voltage

I am messing around with some 555s I bought a while back (NE555N from STMicroelectronics) and I'm getting some unexpected behavior. I have a capacitor hooked up to both the trigger and threshold pins ...
0
votes
1answer
42 views

555 servo controller “modulation input”?

Exactly as the question says. On the TI 555 Rev. C data sheet, what is the modulation input for the PWM circuit? Also, can I round the resistor and cap. to 10k and .022uf, respectively?
1
vote
2answers
231 views

Simple methods for switching a boost converter, to get a stable output voltage?

I've made a boost converter circuit, with a MOSFET as a switch, and a (7)555 timer operating as an astable oscillator, and it's output goes directly to the MOSFETs gate pin. The problem is that the ...
-1
votes
2answers
100 views

How long will this low duty 555 LED blinker last on batteries?

I know there are many questions about LED blinkers, but I haven't yet found a clear answer for this. I have a 555 circuit blinking a blue led (or three in parallel). I has a low duty cycle (using a ...
1
vote
1answer
139 views

Difference between two 12V PWM signals/circuits (PIC and NE555)

I'm trying to understand the difference between two 12V PWM circuits I've build and tried. The PWM signal is intended to control the speed of a motor. Only not in the way you would expect. The motor ...
4
votes
3answers
114 views

Using timer to power on/off a high current circuit

I'm working on a Arduino project that takes measurements from the environment and sends them to a remote server over WiFi. The circuit should be battery powered and I've measured that what I have at ...
3
votes
1answer
83 views

What is the diode for in this 555 circuit?

Here is a schematic of a 555 setup to create a single shot voltage sawtooth pulse across the capacitor C2. It also outputs a square wave pulse on pin 3. A (reversed biased) Zener diode is used ...
0
votes
1answer
99 views

Flyback NE555N driver and mosfet overheat

I have built a small and very simple flyback SMPS based on NE555N IC. The circuit exactly I did built from is shown below: It works nicely for small loads. However I have some issues with it: ...
0
votes
2answers
102 views

Astable 555 timing circuit (0.5 Hz and 50% duty cycle)

I am trying to build a timing circuit to generate a 0.5 Hz 50% duty cycle signal. In other words 1 second on, 1 second off, and so on... I have searched a few places and found the following ...
0
votes
1answer
59 views

An adapter for disconnecting the current after a particular period of time

I want to prepare an adapter which will discontinue the power supply after a particular period of time. The time period will be provided manually using a switch. The time periods are: continuous ...
0
votes
2answers
97 views

IR proximity sensor

I have built an IR proximity sensor using a normal 940nm IR LED, Tsop 4856 kHz IR photodiode. I have used 555 timer to generate pulses to the IR led. the circuit is working correctly as far as I know. ...
1
vote
2answers
131 views

What do Capacitors do in a System with a Speaker?

I made a circuit based on a diagram from my physics teacher. The circuit has a 555 chip connected to seven wires that make up a circuit. The circuit includes a photocell resistor that acts as a ...
1
vote
1answer
95 views

Barebones, rudimentary audio player [closed]

I'm currently working on the next phase of a top secret art project, which just passed the threshold of the prototype stage. I'm building an electronic project that involves light and sound; the ...
2
votes
1answer
100 views

Combine 2 circuits to get the best of both? Battery management system

I'm working on a battery management system for 2 12V batteries in series, totalling 24V, and I found this very good blog online with 2 circuits that got me very interested: This one, that got me for ...
0
votes
1answer
70 views

Digital Clock Circuit With A Buzzer

I developed a digital clock circuit that simply resembles the function of a stopwatch. The circuit works fine, but I decided to add an extra functionality: A buzz is produced each hour, but I seem to ...
1
vote
2answers
115 views

NE555 timer not working - how to identify the element at fault?

background Im a beginner in the field of electonics, and I have been trying to put together a IR remote control / laser tag system using Arduino Nano. I am using a TSOP4840 receiver and a TSAL6100 as ...
0
votes
1answer
111 views

Simple question (I guess): 555 timer

I want to know if it's possible to have a push button so that when it's activated, it turns on my 9 volts circuit for 10 minutes and then turn it off. Also, I don't want this circuit to consume ...
0
votes
1answer
75 views

Low power timer circuit for solar tracking

I'm making a solar based device but it needs to be aligned according to sun's position in sky , the whole assembly needs to move around 11 degree/hr. So I was thinking of using a timer circuit (low ...
2
votes
3answers
148 views

NE555 Flyback Driver MOSFET failiure

simulate this circuit – Schematic created using CircuitLab I made this simple NE555 Flyback driver. I used a 9V Battery to power the NE555 and a 24V 6A power supply to power the flyback. ...
2
votes
1answer
156 views

Generating PWM from rectified sine wave using 555

I want to generate a PWM signal from a rectified sinus wave similar to the image below using 555 timer IC. I have designed the circuit below for this. I want to get a duty cycle of 80% at the ...
2
votes
2answers
133 views

What is the tiniest, low-power, and efficient am transmitter?

Here are my constraints: I need to build an am transmitter, but it has to fit in a 1 inch diameter and ~1 inch height box. Since the box is very small, I plan to use a CR2032 battery, which is also ...
0
votes
2answers
71 views

555 Timer Astable Multivibrator

Why does the astable mode in 555 timer require two resistors, whereas monostable works with just one resistor ? The cap gets charged through R1 and R2 and gets discharged through R2. But in monostable ...
0
votes
1answer
82 views

Kaustic Machine's Atari Punk Console: Line Output or Log Pot?

I'm planning to make a atari punk console for an electronics project, but i have a question, the original circuit published here: http://compiler.kaustic.net/machines/apc.html has a "line outout". Is ...
0
votes
2answers
111 views

556 dual timer circuit not clear to me

I have the following question about a cascade 555 timer circuit. The thing what I do not understand in this schematic how the second input trigger (2) is triggered for low condition. I know that the ...
0
votes
1answer
107 views

IC555 flyback driver troubleshooting

I made a flyback driver which just uses an astable 555 circuit to drive the flyback. The 4 and the 8 pins were connected to the positive rail. 7 pin was connected to the positive rail via a 1K ...
0
votes
3answers
120 views

How to trigger something once a day [duplicate]

What would be the right thing to use if I want the base of a transistor to be high for 12 hours and low for 12 hours? I ask because I would like to make a circuit that regulates temperature in a ...
3
votes
1answer
63 views

Problems with Atari Punk Console circuit

I am trying to build an APC using the following schematic: And the output is having some issues. Sound only comes out when the rightmost potentiometer is at 0 resistance, and in that position the ...
3
votes
3answers
518 views

Using 555 to generate square signal with fixed duty cycle / variable frequency

I am attempting to design a circuit whose output is a square wave with the following properties: Fixed duty cycle, as high as possible (let's say 99%) Variable frequency, between 0.2 - 20 Hz (I'm ...
0
votes
1answer
65 views

How do I replace a CdS sensor in a circuit with an ALS replacement?

I am wanting to replace a resistor in a 555 circuit with a light sensor, but don't want to use the traditional CdS cell. I'd like to use an ALS such as the Everlight ALS-PDT144-6C/L451. This is the ...
7
votes
2answers
341 views

555 saw tooth generator diodes purpose?

I'm given this 555 timer based monostable saw-tooth generator. This is a known arrangement for this part. The difference from other circuits I've seen is that the bias network of the external ...
0
votes
0answers
209 views

Control 12v motor with 5v PWM

I have 5v PWM (555 generated) and I want to control speed of a motor using it. The problem is my motor is 12v and by diving it with a 5v PWM I can't reach full speed of a 12v motor. my pwm generator ...
0
votes
2answers
165 views

What is the equation for the 555 timer control voltage?

I was just wondering what the equation is to find the 555's output frequency is, when a control voltage is applied to pin 5. That would be very useful for me to know! [Edit By OP] So based on what ...
1
vote
2answers
131 views

How do I connect a 555 timer to a CMOS Input?

I designed the following circuit, using a 555 timer, to supply a single trigger pulse with the same width to digital circuits, no matter how long the button is pressed. The actual pulse output works ...
1
vote
2answers
317 views

Simple frequency deviation to voltage converter

I have a capacitive sensor connected to a 555 timer wired as an astable multivibrator and the free running frequency is 60kHz. When the capacitance of the sensor changes, the frequency of the 555 also ...
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votes
2answers
101 views

Toggling on and off 220V power

I have a 9V 555 timer circuit and I want to use it to automatically turn on and off a 220V water pump. What can I use to connect the timer and the pump? Is there like a transformer or something?
0
votes
2answers
55 views

Random timed output circuit [closed]

I am in need of some help with a project. I am trying to build a circuit that will turn on three LEDs randomly on a 1-5second cycle. I have the basic when it comes to electronics, but get stuck on ...
1
vote
1answer
99 views

Power a circuit and read output from tablet microphone port

I have a project that I'm currently powering with a AAA battery, providing 1.5v to a simple 555 timer circuit. The output of the circuit goes through a voltage divider into the microphone input of a ...
1
vote
3answers
228 views

Can you make a waveform asymmetrical with the 555 timer?

Using a 555 timer how do we output a biphasic square wave instead of a monophasic? Is there any way to make it asymmetrical? If not are there any other devices or circuits to use to make an asymmetric ...
1
vote
3answers
260 views

Control RGB LED without microcontroller

I have an RGB LED that I'd like to change from green to red when a circuit is completed. While I know this is very simple with tools like an Arduino, I'd love to not use a microcontroller. Would it ...
0
votes
1answer
101 views

555 timer multivibrator charge and discharge

With this kind of connection I expect 555 to run as a multivibrator. As far as I understand the discharge of the capacitor should be via R2, while charge of the capacitor via R3 and D1. => discharge ...
1
vote
1answer
136 views

How does a series capacitor affect a square-wave on-off signal?

This question refers to the book Make electronic's experiment 18. I have included a picture below. ...
0
votes
1answer
120 views

IC 555 timer to provide oscillation for high amp electromagnet

I am using a self-built electromagnet in my project that consumes 9.0 amps at supplied voltage of 12 VDC. I don't mind even if amps goes high. The power supply I am using can provide up to 30 amps. I ...
0
votes
2answers
296 views

DAC to run a 555 Timer [duplicate]

I am trying to create a PWM signal using a POT from 555 Timer to control speed of a 5V DC motor. I have a development board with a C8051F020 microcontroller, a 100K POT and an LCD display. The ...
0
votes
1answer
582 views

How to design a binary counter with 4029 binary counter ic

I am trying to build a circuit that counts up to 15 or 1111 in binary using a 4029 ic and 4 LEDs as demonstrated in this video. I have studied the 4029 datasheet, and I still can't figure out how to ...
0
votes
1answer
144 views

Get ADC value to run external 555 Timer

I am working on Motor speed and position control. The requirements of the project are: 1. Set a speed to run the motor at a particular frequency. 2. Use a potentiometer to set the speed displayed on ...
1
vote
2answers
681 views

555 to drive a MOSFET

I wish to drive a MOSFET using a 555. I dont have a driver handy, will it be fine to use a transistor instead? So the output of a 555, could activate a transistor(as swtich), which allows a source to ...