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What are the recommended decoupling cap values for these. The cmos 555 datasheet mentions that they can be smaller but does not actually give any suggested values. So how small is 'small'? And I have seen people using them for LM358 but my datasheet does not mention them.
you can make simple delayed timer by using CD4538 or 555 timer I.C, simple google it and you will find your require circuit Fragrance
why not sense hotspot temp and regulate fan speed automatically. A 3 minute timer is possible with Johnson COunter and Emitter Follower or FET buffer with OP Amp Feedback to reference voltage created by 1 minute clock and 3 stage control but only using extremely low leakage plastic Caps and big >20MOhm resistors. using CMOS Schmitt (...)
I have a simple repeater controller using a simple timer ic which is the LM 555..du7dlz
Design square wave oscillator using 555 timer operating at 8khz with 50% duty cycle. need sample design and computation/formula. :)
Hey, I have this circuit idea of which I'm somewhat confused about its logic on how I should on to implement it. I have a voltage sensing section that gives me a square wave of 12V DC. This is applied to a buffer stage which produces 2 12V DC Square Waves on parallel lines. One line goes to a mosfet A which is connected to a coil load and the sec
Hi frito23, Okay, I'm having difficulty seeing the details of the pin uses in the schematic, when I enlarge it gets blurry - sorry. If you haven't quite resolved this yet, if you don't mind could you maybe re-post the schematic larger/as a jpg, please, and I'll be happy to scratch my head for a while, not promising anything but I'll gladly give it
I want to build a circuit that scans my 4x4 keypad using a binary counter and a '138 to generate the row scan and then read the results with a '374 which is read by the processor. The counter is clocked with a 555 timer. The counter will have to reset after it reaches 3. The resistors are pull-down. What would I use as a counter? A '161? And (...)
You could use two time-delay relays. No soldering, but lots of money. Now might be a good time to learn to solder! I would look at using a 555 timer and a couple of transistors. They are cheap and plentiful. But if you REALLY don't want to solder, you could use a breadboard.
Hi, I'm using a 555 timer to set the output hi for a short period of time and then back low. The problem: if the trigger low signal its shorter that the output toggling time the circuit works fine. If the trigger is longer that the output time, the output will stay hi for the hole trigger time (the RC will recharge). It is any work (...)
Instead of a 10 mH coil, use a larger flat coil, like 50 turns of 0.5 mm dia.wire would on at least 6" diameter, in a tight strain. Detecting metals requires to affect the coil inductance by a larger metal mass. using a small coil might only detect a magnet if it affects coil iron core. Better metal detectors use larger coils, also the beat-frequ
This thread should be part of his original thread about an ESR meter using a 555. This circuit also has the capacitor being tested that is shorting the output of the 555 which will destroy the 555 if the 9V battery is good. The circuit does not measure the ESR of the capacitor, instead it measures the output resistance of (...)
So connect a 10 K resistor between the battery +terminal and the non earthed capacitor test output terminal. Warning you might find some 6V working capacitors that won't like 9V. So for these, put another 10K across the capacitor under test, this will reduce the 9V to 4.5V. There seems to be a fascination with ESR meters on this board, low va
I am puzzled by your question! Multisim is a schematic simulator and NOT a programming language. But you can introduce delays using RLC components or timer chips like 555 or 4538 cmos. These are not options but you have to actually connect up the components to implement your delay. Allen
- Use small footprint 555 IC's which are for low power application like CSS555S, TLC555, LMC555. - If using above IC's already, run 555 power at 2V or smaller supply which will reduce the power to few uA. For this dc-dc charge pump step down regulator can also be used as in here:
I am trying to create a circuit that will delay coming on and then turn on 6 LED's. As far as I can tell, my diagram is correct (please correct me if something is wrong.), but I do not know the values of the resistors connected to the npn and pnp transistors I am using or how to calculate them.
Hi everyone, I've build a metal detector circuit using a 555 timer as explained in this link: al-detector-using-555-timer.html instead of using a speaker as the informer of detecting I am checking the frequency at the point were the speaker is shown in the diagram. The (...)
With a +12.0V supply and a 200mA load some 555 ICs have a maximum output voltage of +9.5V as listed on its datasheet. If you add a high current P-channel Mosfet then the output will be close to +12.0V with plenty of Amps. Very correct, while using MosFet you need to wire two transistor (one NPN & one PNP) in a "tote
I am trying positive pulse triggered monostable using NE 555 timer IC. Trigger Pin - 2 triggeres at 1/3 Vcc, can this value be lowered to say 1/4 Vcc or even less. A link to related issues will also be helpful.
I have a square wave from the astable multvibrator coming out and I want to invert the waveform for the monostable. I want to invert the square wave using a transistor. I don't know how to invert using transistor. Could somebody tell how to use a transisor to invert a signal. Thanxxx
I hope its helps you...
Have you considered using the 555 timer IC as a pulse generator? It will provide up to 200 mA to your load. It is inexpensive and easy to use. - - - Updated - - - Sample configuration of 555 as a pulse generator. The resistors and capacitors at left determine the frequency. By altering volt level on the p
You want to rest the timer or any other module to be reset using 555? what is your actual requirement?
For a first guess, have a look at 555 timer application notes. If you want zero current consumption in off-state, a different approach might be required, e.g. using CMOS logic ICs or transistors.
Hi! I am nt very familiar with electronics design. Just have some basic knowledge. For one of our projects to heat an alloy with capacitive discharge current being controlled by SCRs, i need to make a 3 stage time delay trigger circuit using 555 ics(or any other suggestions?). Could anyone guide me doing that. Ther
good day. i have the idea of "power failure and power resumption indicator/alarm" (using 555 timer) as my project. i have seen a power resumption circuitry. i'd like to use this concept but since this project only applies to the resumption of the power supply, can you please help me about modifying it. thank you very much.
Hi all, this is for my science fair project. I am trying to make an electric arc using ferite transformer in flyback mode. I have done a rough calculations of the windings and power source as follows. Target voltage = 10-15K blocking oscillator using transistor or bjt ot igbt. power source 4/8 volt lead acid battery but not 9 volt mike batt
i already solved it using a 555 timer powered by a battery and a relay to the output.but the project coordinator has now specified that a battery cannot be used for powering the delay circuit. How about to use the CMOS 555 timer (LMC555) instate and use a big capacitor instate a battery ?
There are ways to get a 555 to act as a PWM modulator (using some external components), but simply modulating the CV pin is a very poor way to do it. Besides the severe nonlinearity in D, you'll also be modulating frequency quite a bit. A more straightforward way to make a linear PWM modulator is to create a nice linear ramp waveform using (...)
Hi I want to produce siren sound by using 555 timer.But i am getting tick-tick sound for 2Khz frequency...what should I do, i am using external drive piezo element.PLEASE HELP.
Thanks. The o/p of 555 timer is it connected to the gate of thyristor?I'm using six thyristor
I need to generate a square waveform with 30% duty cycle having +/-5volt peak voltages by using a ttl circuits
This design allows you to vary the output level (using R5) and allows you to switch between square wave or sine output. You can easily design the 30kHz clock source with a 555 timer.
G'day Mate, Bit tricky using passive components only! but depending on how accurate you need the 5 seconds a 555 timer should give reasonable results... remember to use an extended temp range part for automotive use... Follow the design of the mono-stable configuration as shown here... h
Hi, Anyone who has experience with that how to get a PWM signal whose Puls should be controlled based one the I/P voltage ?5V using simple OP-Amp ? Thanks in advance
Hi, Thats always the problem when using someone elses code, if it does not work you are stuck. Perhaps if you post the site where you got the code from we can see what the whole idea is and how it should run. Its also uses a strange collection of parts, running a 40mhz and using a 555 timer chip ? The code you (...)
You will always struggle with long time constants using simple circuits due to capacitor leakage. Long time delays are therefore usually made using higher frequencies and counters/microcontrollers. Keith.
The 555 timer IC can be used to do what you want. Example hits using an internet search: The concept is also known as a voltage controlled oscillator (VCO). There's the question of linear response. Do yo
in atmega i can give an analog ip becauge in atmega yhere is inbilt ADC present. can i also give analog ip to 8052. actully my friend says that i can controll pwm in 8052 by analog ip voltage without using ADC.
how can i control the width of square wave by varying the voltage without using 555 timer ic. actually i am using potentiometer and mirocontrollor. if there is another component required then plese mention. use the timer of the microcontroller to set the period and invert a digital output on each (...)
Hi i would like to make an frequency generator using a 555 timer chip. The frequency should vary in the range of 100hz to 1kHz with a reasonable duty cycle (20-80%). I am using the circuit below. Varying r2 alone would not do the job because at r2=0 the duty cycle is 100%. I found out if i started with r1=2k2 and (...)
Simply use any general purpose Transistor available in the market, most commonly available general purpose transistors are c828, c1383 and 2n2222 will work fine. drive the base of the transistor using output of the 555timer with around 5v zener diode connected between the base of the transistor and output of the IC. Connect the Led with (...)
Hello sir i want to make a mono stable multivibrator using 555 timer with variable timings in the range of .1 secs to 60 secs . how can i design it please tell me with the circuit diagram & if possible the related formula (...)
im using Agilent ADS 2009. how to create a 555 timer? please help. im a newbie in this software.
A very simple voltage trigger alarm. You may add a timer module using for example the CD4060 circuit, to trigger the alarm in short beeps, followed by an adjustable stop time period and circuit restarting automatically over a period of time to keep monitoring as a remainder for charging the batteries.
I think it?s the best solution to use a timer, the question is: do you want to make one timer (by using a standard 555 circuit, capacitors and resistors) or considering buying off the shelf product? ---------- Post added at 19:37 ---------- Previous post was at 19:30 ---------- e.g. [COLO
Hi Please help I have done PWM using 555 timer and controlling duty cycle using potentiometer and its works but now I want to use an LDR to control the duty cylce. The final pwm output will be used to controll dc motor. My final circuit will sense light and run motor forward and back ward at a particular speed (...)
Pulsed Infrared Sensors 38 kHz Pulse Generator with a 555 timer 38-kHz IR LED Circuit Infra-red Light Barrier using 555
In the given circuit a monostable using NE555 is used to play a UM66 IC for about 11 Sec. The circuit is working Ok but the problem is, it is consuming enormous power. My friend using this as a calling bell for his ill mother. According to his report the bell needs a new 9V battery pack every alternate day. Any solution? The speaker is of (...)
Maybe you need to have a timer and delay using a LM555+CD4017 70183 johnson counter for your 6sec delay ?