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Don't expect quaility audio! The circuit just pulses current to the speaker but needs to be driven with pulses going from less than about 0.6V to peaks of more than 1.5V to operate. Too much low voltage or low period will damage the speaker. Brian. As I mentioned earlier, I need to amplify simple tunes (300-800Hz)
What do you want the audio to be and what effect on the output do you want? The 100k pot adjusts the frequency of the 555 oscillator. The servo might need pulse width control for it to move, not a variable frequency.
With respect to this a 12V supply I am only getting about -7V out of it with a CMOS 555. Does anyone have any suggestions on how I could get it closer to -12V?
I am generating 300us Monostable Pulse through 555 IC with 12V Vcc supply.The frequency is 5Hz. The pulse width is ok but when I see the waveform on the oscilloscope, the pulse shape is not good. The pulse rises to 10V very fast but after that exponentially goes to 11V and while discharging it drops down to 3 V fast but then exponentially discharge
Hello, How to build Sin wave oscillator for learning??
Could you be more specific? Do you want a digital circuit? An analog circuit? Any constraints? frequency? A simple 555 timer would do this. So could an FPGA.
I have used a 555timer to output a pulsed signal. The amplitude is 4.6V. I am then inputting this signal into a transistor to pulse the LED. However when I do this the amplitude drops to 0.8V. How do stop the amplitude from falling when I put it through the transistor? :?:
The 555 has a 'ctl' pin. By applying a voltage, you change duty cycle. At the same time it changes frequency. If you're lucky the resulting waveform will suit your Also check out this collection of 555 circui
The values of the timing capacitor and resistors have to be changed for different frequencies (C4, R1, R6). There are various combinations that will work but I suggest 470K for R1, 510K for R6 and 10uF for the capacitor will be fairly close at about 10.05 seconds intervals. If you need very accurate timing I do not recommend using a 555. Brian.
Poking around the internet I just found a very simple ac conductivity circuit using a cmos 555 that outputs changes in frequency with changes in conductance, ideal for driving a micro 555 has DC pulses as its output. The DC causes electrolysis of the probes which c
therfore the discharge of the NE555 has no function.Besides need to flip the input voltage, I wondered how the capacitor can be discharged. I guess it can work with a bipolar LM555 (but not the 555 CMOS version) by utilizing the small positive output voltage of the saturated switch transistor, about 5 mV with 15V supply
hi, To keep the cost down I would use a 555 timer as a PWM generator for each chain. For only 20mA per LED chain, from a 24Vdc source, a BJT or a 2N7000 MOSFET would be suitable. The frame frequency of the 555 PWM generator could be selected for each LED colour chain. Lots of simple circuits on the web.
That means you need a zero-cross optoisolator triac driver (MOC3083) then you might use a simple 555 to generate a PWM signal with very low frequency (T=few seconds) to drive the optotriac. This way, the voltage applied to your heating element will be half waves multiple thus there will be no stress on the mains power supply.
CMOS version of 555 takes 30uA
I think the piezo transducers operate at 40 kHz. So first adjust the 555 frequency to the proper 80 kHz. Only then there will be any ultrasonic "beam" generated and detected. Use an oscilloscope to adjust the correct frequency, then connect it to the receive transducer. You will see a sharp voltage peak at 40 kHz, and hopefully the thing (...)
Output voltage and impedance question is still pending. I presume it's a digital signal and exact voltage levels don't matter. Generally a 555 with a current source output stage. The simplest current source would be a resistor, by the way.
if you know a little electronic, you can build timer with 555 easily. just search 555 timer
If your 9V battery actually produces 9.0V then the output of a 555 oscillator without a load goes from 0.01V to 7.7V over and over. Maybe your multimeter cannot accurately measure the level of a frequency so low since they are made to measure 50Hz and 60Hz. Please post your 555 schematic.
The 555 output is a square wave that is full of harmonic frequencies, not just one sine wave frequency. You need a bandpass filter for each frequency that is not a simple capacitor. Why not use a touch-tone encoder IC for the transmitter and a touch tone decoder IC for the receiver instead then the frequencies will be accurate and (...)
The transmitter uses a 555 that switches its output high and low digitally so the tuned circuit on its output is useless. The frequency is far too high for a lousy 46 years old 741 opamp. You show its gain as high as 1000 then its frequency response is limited to only 900Hz. You have the opamp as an inverting amplifier with an input (...)
The datasheet for the Cmos 555 ICM7555 from Intersil has graphs showing the typical output current. It can source only 2mA (but its minimum current might be only 1mA) and sink 10mA (or a minimum of 5mA) when its supply is 3V from two brand new AAA alkaline cells then you will watch the LEDs dim even more as the battery voltage drops to 2V. The Cmos
Dear Edaboard engineers, I need help here! There is this Sine Wave Inverter circuit I am working on. I did not originate the circuit but instead with my own EDA software I redrawn it in a new way and better layout for easy understanding and I also corrected some mistakes in the the original circuit but still, I couldn't get it to work! I get high
You forgot to post the schematic of your 555 somehow driving an LC tank. A MUX works with analog or digital signals. A shift register is digital only.
555 is an option. The application circuits in 555 data sheet should give you an idea how to make astable and monoflop.
Actually, I want to use only one POT to change the frequency such that the duty cycle should remain fixed. Can't be easily achieved with a 555. A standard OP generator can do it, see post #2. Asymmetrical thresholds set the intended duty cycle, a single potentiometer the time comstant.
Assuming I am OK with setting up a 555 bases PWM (53kHz) to run a few IR LEDs and that I can get an unmodulated IR LED and phototransistor to drive a red LED as an indicator as you pass your hand over the phototransistor. What is the best way to go about demodulating a 50kHz IR signal coming from the phototransistor. I have tried a high pass
If you don't mind a simple RC timing network, then you can use an ordinary 555 IC to produce pulses with this
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
ne555 maximum operating frequency is only 100KHz. Why not use a crystal oscillator?
Hi all, is there any way we can work the 555 VCO such that its frequency increases when input voltage decreases ? thanks.
lets say its DC so we need to use DC DC converter. but one problem is if we use 555 to generate current pulse of our desired frequency vlotage drops up to 1. 2 or 1.8 volts. if i use 3.7V battery and generate a pulse of 2khz and use Dc Dc converter i think i can get the desired result but the problem how to generate p
dear frank, please tell more about diodes with op amp. whats is your opinion about a 555 based vco, I dont need 100% modulation. thanks.
Hello sir As we know 555 astable multivibrator has a capacity to generate high frequency oscillation say 100 khz max. so what about the case if the astable design is transistorized ?
The higher the frequency, the smaller the transformer. It's easy to find transformers for audio frequencies and they can be tiny. Any oscillator would work, even something based on a 555 timer. JP
The circuit is a fully-developed versatile driver for the electrodes (arc welder, I guess). All the components are popular. It is versatile because you can vary the frequency and duty cycle to the electrodes. If you wish, you can experiment with just the 555 timer IC driving the mosfet. There are easy ways to adjust the frequency and duty (...)
A 555 can be used to make PWM but your circuit is missing the parts for it to make adjustable PWM. You simply made an oscillator. The duty-cycle of the pulses must change to make pulse-width-modulation. All datasheets for the 555 show how to do it.
Just in case someone needs a better 555 there is the 7555
hi guys! I wish to generate frequency from 17Hz to 17KHz. can anyone help me?
my tsop 1738 output waveform shows ringing.also the 555 output used in the receiver circuit too shows ringing.please why is this happening? the ir led output of the transmitter shows a frequency of 38 khz and are pulses with ton less than toff though the pulses are not perfect. what should be the tsop output?what should be the 555 output (...)
I am assuming that you are using full H bridge? Run your 555 at twice the frequency required. Use the output from this into a flip flop. Now you have two square waves exactly out of phase. Remember, you must take great care that there is some way to stop the wrong transistors conducting at the same time. Imagine, the top Lh. and bottom Rh transi
There are two causes of frequency drift :- 1, thermal. The other, 2, is sensitivity to power supply voltage, the 555 is very susceptible to this. That's news to me Frank. One of its well known attributes is that in the astable mode it is indifferent to changes in supply voltage.
use 555 timer that can do that
Hi all, How to generate a sine wave of frequency 50Hz +/- 10Hz controllable through a POT? the amplitude can be +/- 5to12V, duty cycle 50%. 555 and 566 give only +ve wave forms, i need a wave with alternating polarity. thanks.
You can do everything with the MC, you do not need the 555 and 4017. Everything in SW code
555 Timer - frequency and Duty Cycle Calculator 555 Calculator
if the 555 is in astable mode the multimeter reading maynot be correct since it is not pure dc
The 555 is a good timer but a poor RC oscillator. It is not worth time to select stable R and C to improve its stability. You could use it with only 3Vcc to prevent heating .For stable frequency source, select a quartz oscillator at e.g.10 kHz, then use TTL dividers to get your frequency. A 74HC390 can divide by two, five and ten, etc.
are you driving the mosfet gate directly from the 555 output with a frequency of 437KHz?
The original design is working in Proteus and real life, but of course not with a frequency of 500 kHz. Review a 555 datasheet about frequency calculation. 555 isn't very good suited for the intended frequency range, but will hopefully work. I would prefer a simple thing like 74HC14 oscillator or similar.
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 r2=4k7 and c=1uF. (...)