New answers tagged pwm
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PWM Driver for PIC12F1572
RA2 should be configured for
TRISA5 = 1 (input);
ANSA5 is not implemented so the pin will naturally be in digital mode;
...
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pwm 0-5v to 0-12v , what's wrong with this circuit
In the schematic C2 is connected between +12 V and the emitter of the opto-coupler, which is the output. When the opto-coupler transistor is off the capacitor charges through 10k resistor U7. When the ...
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Did a PWM fan tach signal fry my ESP8266?
Assuming you measured the voltage with a standard volt meter, you would have been looking at the average voltage not the peak voltage. Have a look at the signal with a scope (or a peak measurement ...
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Smooth a PWM to DC stable
You usually do this with an RCD network as sketched below, no transistor necessary.
simulate this circuit – Schematic created using CircuitLab
R2 is optional. It can be replaced by an internal ...
- 18.9k
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PWM Driver for PIC12F1572
When Q1 is not conducting, there will be no current through R1, so the transistor's collector voltage will be the same as that of the supply, 12 V. Is that more than the microcontroller can tolerate?
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Low Percentage PWM LED Brightness (Equation?)
I'll try to give a helpful answer instead of telling you that this is a question of human perception and very difficult to answer correctly.
Gamma correction is exactly what you need and want.
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PWM circuit that switches MOSFET with soft edges
Relevant discussion from another community: https://www.eevblog.com/forum/reviews/any-opinions-on-the-aixun-t3a/
Buzzing isn't mentioned (or audible in the video), but it might be that build quality ...
- 24.3k
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Low Percentage PWM LED Brightness (Equation?)
You will have no trouble seeing that LED going at 0.01% duty cycle in a dark-ish room. To turn the LED off, the PWM setting must be zero. That’s all there’s to it.
Many LEDs, if pulsed at say 50% of ...
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Low Percentage PWM LED Brightness (Equation?)
Human vision has a logarithmic response, and will be more sensitive to low intensities. PWM type drive also triggers another vision path: persistence. So the eye will see the LED pulses and stretch ...
- 50.1k
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Low Percentage PWM LED Brightness (Equation?)
LEDs are linear with duty cycle so long as your on time is relatively long relative to the rise time of the driver/LED combination. This will depend to some extent on how you switch it, but probably ...
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How do you size a resistor when the current and voltage flowing through it are impulsive?
You need to ensure the average power dissipation is well within the capabilities of the resistor.
It would be best to use a resistor that has a pulse-power curve in the datasheet. Obviously you also ...
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How do you size a resistor when the current and voltage flowing through it are impulsive?
In this example the load is the gate capacitance.
Energy dissipated by a resistor charging a cap is 0.5*cv^2.
So plug your gate drive supply voltage into V and the gate capacitance into C. Then ...
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Voltage not varying with duty cycle
I don’t know what's the error as I have seen in buck converter that with a capacitor in path of the PWM, as the duty cycle changes the voltage changes. Using that concept of buck converter and voltage ...
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Voltage not varying with duty cycle
You have a load of 1.6 MΩ on a capacitance of 5 nF. The time constant of this is \$ \tau = RC = 5 \times 10^{-9} \times 1.6 \times 10^6 = 0.008 = 8 \ \text{ms} \$ but you're recharging at 25 kHz (...
- 170k
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LED indicator for PWM signal
If you want to implement this without using the ESP, one solution would be to charge a small capacitor via a diode with the PWM and use an constant current driver to drive the LED with a constant ...
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LED indicator for PWM signal
It sounds like you want an external way to ensure that a PWM signal is actually present, rather than trusting the ESP software. Sure, so you could route to the PWM signal to a second GPIO as well and ...
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Problems controlling the Roman Black regulator using ESP32
I have modeled the circuit in your post in CircuitLab
simulate this circuit – Schematic created using CircuitLab
As can be seen by a simulation run, the start-up current consists of very low ...
- 20.3k
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STM32, how to create microseconds long custom pulses
Simplest method Use DMA to transfer to the GPIO. It is much more precise than SPI. Simple use a timer to trigger the DMA transmissions. It is very precise. I use it in our test devices where jitter ...
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STM32, how to create microseconds long custom pulses
There are many ways of doing it - using SPI, a PLD or PIO (programmable IO state machine) hardware block if the chip has those, or even just loading new compare values into a timer using DMA. Each ...
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STM32, how to create microseconds long custom pulses
As proposed by Velvel, using SPI (in DMA mode) is probably the easiest approach.
The SPI peripheral should be configured like so:
Mode: Transmit Only Master
Hardware NSS Signal: Disable
Data Size: 8 ...
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Correcting error in 555 PWM circuit
Adding components like diodes makes it much harder to accurately compute the timing of a 555 circuit, since it will be very sensitive to variations in precise diode characteristics. A variation on ...
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Correcting error in 555 PWM circuit
Yeah i figured that the diode was causing the error, i guess i'm trying to figure out how to calculate that so i can account for it in my equations.
The equations you cite are simplifications of the ...
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555 Astable Multivibrator Voltage Spikes
Mine was identical. I used a 33nf cap on pin3 to gnd. This did change my "On Time" and "Off Time" a tad but I just switched the pots out to higher values.
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Controlling stepper motor with DRV8833
It seems you have a 4-wire 2-coil bipolar stepper motor, it is not controlled by a single PWM signal. You need to drive all four inputs (Ain1, Ain2, Bin1, Bin2) of the driver to obtain synchronized ...
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