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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.
You can use schottky diodes to make the drop-loss over each diode less. Check your load current. The 555 can only provide about 100 mA of peak output current to charge the caps. You can also increase the frequency ( 1/2 your timing cap value) to have energy transfers more often to your load.
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? :?:
I am new to 555 timers and circuit design. I am trying to figure out a way to control the duty cycle and frequency. I need a controllable frequency from 15kHz to 60kHz and to be able to adjust the duty cycle for motor speed control. Is this possible?
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.
i need to measure resistivity between two points using AC current , what kind of circuit I would need for this ? thanks 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 ! http:
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.
I have the need for a low frequency (say 1kHz) oscillator as follows: - Really inexpensive - Reliable start-up -40 +90 deg C - 0-5V output @ <10uA - Accuracy 20% - Duty cycle 25 - 75% - power source; +5Vdc The tried and true 555 circuit is pretty cheap: $0.44@qty10, or $0.22@qty100 (Digi-Key pricing) Does anyone have a cheaper
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 (...)