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Oscillator And Duty And Cycle

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32 Threads found on edaboard.com: Oscillator And Duty And Cycle
Hi, These are just a few, from RC + 3 inverters, single op amp, logic + crystal/logic + RC, two transistor + RC oscillators, the CD4060/HEF4060 + crystal/RC, a VCO IC, ..., ..., and there are plenty more. The "Relaxation oscillators" pdf has the one using a single op amp and a few (...)
In terms of microchip ECCP parameters, your initial post shows a PWM signal with 50 % duty cycle and 30 % dead band. Dead band range is 0 to 127 Tcyc, so 6 ?s should be possible for 50 kHz PWM frequency and 4 MHz (...)
This is basically a continuous Buck regulator switching oscillator than regulates the pulse width for an average DC voltage across Vbe controlled by D1 zener voltage , Vbe and Ie*Re and duty cycle. Offline buck designs have improved over this (...)
I would use a dual one shot with suitable buffer and current limiter R to a few Watts of white LEDs, over driven but not to exceed max I with < 20% duty cycle. 1st one shot in retriggerable multistable vibrator or oscillator mode adjusts f vs R over a very wide f range with suitable RC values (...)
It's also possible using an oscillator circuit to generate the frequency and a separate monoflop to generate the duty cycle. Or a ramp/triangle generator and a comparator.
Like barry said, 555 only produces pulse's, not sine wave. Pulse: Sinusoidal: Check this app note from TI. Specifically page 15-11 (Figure 15-8). It uses
I don't agree about "unusual". A 555 circuit with feedback from output instead of DISCHG pin can be already found as 50 % duty cycle oscillator in the LMC555 datasheet. The variant with diodes and variable duty cycle is at least frequently used.
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.
hii, I have to design a flyback smps of o/p power 3W. I want to use 555 timer as PWM oscillator and control the duty cycle from 0 to 50% using control voltage. 1. In what configuration 555 timer will be configured, whether astable or monostable mode 2. How can i limit the duty (...)
First of all Hello everyone!! I have a problem a very big one I am new to verilog and i have a Spartan 3E FPGA Starter ,i am facing a rather difficult problem for me i want to create a verilog code to make a frequency generator from the 50Mhz Spartan s internal oscillator i need a frequency generator with frequency between 1Hz (...)
Hi Er_SJSU, Without using a counter if you generate a delay just using a Capacitor that becomes very unreliable and bulky. Even with a 100uF capacitor to charge 1V in 60sec you need a current of 1.66uA. So your leakage current of the capacitor must be really low over all your operating conditions. If you already have an oscillator, why (...)
Hi, i will write a PIC18 program in C and examine my program using MPLAB simulator to generate a square wave signal with 60KHz frequency and 60% duty cycle so how can i do it if any one can help me (me new in Microcontroller world) thanks for all
I have a 38.4khz crystal oscillator circuit that i have running into a 4060 ripple counter. i thought that if i used an and gate on the Q5 and Q6 outputs that i would get a 400Hz frequency (2^5 + 2^6 = 96; 38400/96=400), but i'm getting a 350Hz with a 25% duty cycle. I (...)
Hi simon, Check the feedback section of your inverter. Check any optocouplers and associated resistors and potentiometer. Check the connection of these parts to the oscillator and use a multi-meter to check the output duty cycle (...)
if your system has a clock, and your OFF state does not have to be a continuous number, you could use a programmable counter for the OFF state. If not, you can use a relaxation oscillator where you control the time constant for the OFF state.
Axmmm, microcontroller with hardware PWM module, quartz crystal in oscillator (nor ceramic resonator), duty cycle 50% ? In Proton+ it should be something like: Device 16F627 Xtal 4 PortB_Pullups FALSE All_Digital TRUE HPWM 1, 127, 2400 End
If you are using an 8-bit Pic, 5MHz will not be possible. You set the pwm period by writing to the timer period register, normally timer 2. The faster you go, the lower the duty cycle resolution becomes. If you write a 5 bit value to the timer period register, ie. PR2 = 0x1f, and you have a 20MHz (...)
I want to generate square wave oscillation using PIC16F873A with fixed duty cycle say 50% but i want to be able to change the frequency of oscillation from 1Hz to 1MHz by keying in the required value and make the PIC generate it. 20MHz crystal oscillator is used. pls, i need help on how to do this.
Use a crystal oscillator.
This technique is sometimes referred to as Replica bias. The output from the crystal oscillator is a sine wave and the digital buffer is supposed to change it into square wave. However, the duty cycle of the square wave is highly dependant on the sine wave's DC and the (...)