1. meshcurrent

    why ccp set_pwm1_duty(250) does not work for servo.

    I am using PIC16F877a microcontroller. My aim is control the servo motor with pwm signal. I can create the pwm signal with RB0 pin with ccs c code. I have tried the ccp1 module to create pwm signal but I could'nt. Why does not work. And I have a question about these two ways to create pwm...
  2. K

    RGB LED colour and brightness control

    I am a mechanical engineering student so only have a basic knowledge of electronics. I am using some RGB LEDs and I want to control their colour temperature and brightness. I am controlling the colour temperature with PWM but want to control the brightness with another method so the colour is...
  3. dmarciano84

    DC Fan PWM/Speed Sense

    I am working on a project (based on the PIC16F18877) to which I am planning on adding a PWM DC brushless fan. However, I have never had to work with PWM before (or even DC fans) so there are a few things I am not clear on that I am hoping to get clarification on. I just want to make sure I...
  4. B

    Fan Controller - Thermistor Circuit

    Hi folks I am trying to build a circuit which will govern the speed of the fans in my solar cabinet based off the temperature inside. https://www.circuits-diy.com/temperature-controlled-fan-using-555/ I built this circuit hoping it would work with 6x 24v / 0.08A PC fans (40mm) I have 3 of...
  5. A

    Getting a Constant Signal from a Demultiplexer

    So I have a circuit whereby a PWM signal is being sent to a demultiplexer, and the demultiplexer sends the signal to a MOSFET which takes it and allows a current to flow through the nixie tube. The higher voltage value in the original PWM signal, the more the nixie tube will light up. My issue...
  6. ponas.jonas

    How to control a linear drive motor using PWM

    I am trying to control a linear drive motor with a built-in encoder. I am using a motor driver to move the linear motor. I have calculated a PWM signal for a PWM frequency of 1kHz and a duty percent of 50% with the following values: Internal Clock = 180 MHz Prescaler = 180 Arr register...
  7. I

    Mosfets getting damaged and i don't know why

    Hi, I made a really simple PWM generator but the mosfet placed in the circuit keep getting damaged even though they are not heating up. The load in the schematic is a 20ohm heating element but i also tried to replace it with much led and resistor but the mosfet still get damaged after 1 or 2...
  8. PatteGris90

    Led boat lights

    Hi all, I am trying to build some underwater lights for my boat. I am using 10 pcs of 3W RGB 6 pin leds in series and i have tested the output. I am currently using a constant current constant voltage driver. I would like to make a pcb capeable of driving the 10 leds and controling them with...
  9. G

    Inductor / Coil / PWM door lock understand issues.

    Hi, I have returned to an old issue I am struggling with – my door lock solenoid project again. I have created a really simple LTSpice circuit driving my solenoid at 1Khz, 50% duty. The solenoid I measured with an inductance meter, 35mH and 25R series resistance, this has been entered into the...
  10. Younes Thabet

    What is the use of an 3-state octal buffer/line driver?

    Hello all, I have encountered an AHC244 chip used to drive LEDs (Something like in the attached image) so I wondered why not just drive the LEDs with the uC pins? And also I have seen this IC used with some PWM signals as inputs to it! in this case, I am guessing the output would be the same...
  11. S

    Analysis generate PWM use op-amp.

    Please help me to understand this circuit about analysis voltage each point and how to calculate time charge and discharge time on triangle signal. If use Op-Amp NJM2904C Thank you.
  12. J

    Arduino PWM

    Hello, I have an arduino Uno that I am trying to use to control a 12v motor. I need to control this motor. I have tried using the analogWrite(); method, and also changed the frequency but still could not get my valve to move. This valve can be controlled via linbus or pwm according to the...
  13. H

    Wiring 25 LEDs with a PWM Dimmer

    Not usually one for asking questions in forums, as I'm usually able to find solutions with my own research, however, I've been looking at this over a period of days now, and the deeper I dig, the more confused I'm getting.. I'm a Computer Science student, not electronics, so please go easy on me...
  14. avi9526

    LED driver with minimum duty cycle of 0

    hello I have a practical task to make a simple LED lamp. I was using LDD-1000 for that purpose. But it does have minimal duty cycle of 20% (output is filtered so it's 20% of max. current) . Was looking for an alternative that could provide smooth control of current from 0A to 1A. Kinda lost in...
  15. TheMasterXXXXX

    Issue controlling PWM with thermistor

    I am attempting to use a thermistor to control the PWM of a 555 output. Ideally, I want the duty cycle to be 100% when hot (~90°C) and 0% when not hot (~25°C). I am doing so by placing the thermistor as R2 (RB) in astable mode with a forward biased diode in parallel to R2 (allowing a duty cycle...
  16. -live wire-

    Help controlling multiple nema23 stepper motors with esp32 and motor drivers

    Hi, This probably isn't super complicated but I have to control 3 stepper motors simultaneously with an esp32 for part of a robotic arm. These are the nema 23 stepper motors I am using, they are normal open loop 4 wire stepper motors. These are the motor drivers I am using. One pin tells...
  17. T

    Best method for converting PWM to analog signal?

    I want to make a circuit that will convert a PWM signal to an analog signal. I want the circuit to be able to work on higher frequencies as well though (up to 15 kHz). Would an RC filter be the best method? Any reference design examples for this?
  18. T

    Standard LED PWM Frequency?

    I'm trying to determine a standard PWM frequency output for RGBW controllers. I see a lot of constant current LED chips call out a maximum PWM frequency input between 300 and 500 Hz. 1. I assume this indicates that 300 to 500 Hz is standard? I've seen a 12 Vdc 385 Hz RGBW controller pass FCC...
  19. T

    PWM Buck Regulator Question

    Questions: 1. Why do switching regulator ICs have dedicated PWM inputs pins? 2. Can you use PWM on a low side switch at the output of a constant voltage buck regulator module? For instance Remcom Power's R-78E5.0-1.0. My concern is that dedicated PWM inputs operate differently than using an...
  20. J

    Please somebody tell me what will be output watts of this PWM circuit

    Detailed description and website link are below. Parameter: 1>.Product Name: pWM 4-Wire Fan Temperature Controller 2>.Work Voltage: DC 11V~55V 3>.Work Current: 0.1A(MAX) 4>.Fan Current: 5A(MAX) 5>.PWM Range: 5%~100% or 0% 6>.PWM Frequency: 20KHz/2.5KHz 7>.PWM Signal Amplitude...
Top