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Grounding issue with PWM fan controller on Raspberry Pi Pico to drive 12 VDC fan

First, don't connect a local 3.3V pull-up to the NPN. It's unnecessary (the fan has its own pull up internally) and it creates a Vcc leak path to the Pico. The fan will make a lot of noise on its GND ...
hacktastical's user avatar
1 vote

Grounding issue with PWM fan controller on Raspberry Pi Pico to drive 12 VDC fan

Ground needs to be connected between the fan and the controlling circuit. Further, there must be no external pull-up resistor: see Intel's 4-Wire Pulse Width Modulation (PWM) Controlled Fans ...
Andrew Morton's user avatar
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Grounding issue with PWM fan controller on Raspberry Pi Pico to drive 12 VDC fan

Simply combine the GNDs from both your 12 V supply and your Pi Pico. Tie them directly together. This is the normal way to do it. The fan internally pulls the PWM high, so you shouldn't do that ...
evildemonic's user avatar
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PWM driver for ESP01 using IRFZ44N

Couple of issues I have noticed: The effective drive (gate-to-source) voltage when the PWM is low is 6V because of the R2-R3 divider. The lowest on-resistance could be achieved with higher drive ...
Rohat Kılıç's user avatar
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ATMEGA2560-16AU PWM control using AVR-C

For PWM control of pins PH3(OC4A) / PH4 (OC4B) / PH5 (OC4C) / PH6 (OC2B) /PB6 (OC1B) / PB7 (OC0A), what timers do I need to use? Timers 0, 1, 2 and 4, with their associated pins? As the digit in the ...
G36's user avatar
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2 votes
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I am Seeking Help to Adjust DC Motor Simulation Parameters in LTspice for Accurate Current Modeling

I initially considered deleting my question, but I think sharing an answer based on my experience is more beneficial. Estimating all six parameters required for a close approximation proved very ...
Mark's user avatar
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Why is the filter capacitor (used to filter pulsing DC) overheating MOSFETs in a buck converter?

@Aaron was right. The MOSFET connections were messed up which didn't allow the inductor current to flow during off state of MOSFETs. The MOSFETs broke the current loop of the inductor while being in ...
irshukhan's user avatar
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Trace width for PCB motor driver board

Using a standard IPC-2221 calculator, for 7A current and 1 oz/ft² copper thickness with a 10°C temperature rise: ...
S_G's user avatar
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2 votes

PWM Dimming of a Low-Voltage DC Incandescent Filament (Thermal Shock?)

PWM to the filament works OK as long as 100% duty cycle drives the bulb at about rated current/voltage. Thermomechanical resonances have to be avoided as you stated as well. Some people try PWM-ing a ...
Kuba hasn't forgotten Monica's user avatar
1 vote

PWM Dimming of a Low-Voltage DC Incandescent Filament (Thermal Shock?)

"Thermal shock" effects incandescent lamps are harmful not because of expansion and contraction, but because parts of the filament that are cold will convert far less power to heat than ...
supercat's user avatar
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3 votes

PWM Dimming of a Low-Voltage DC Incandescent Filament (Thermal Shock?)

Before high output LEDs became available, I made a softstart + voltage regulator for incandescent bulbs to go from 1000+ hours lifetime down to single digit numbers to gain ~50 % efficiency from ...
winny's user avatar
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8 votes

PWM Dimming of a Low-Voltage DC Incandescent Filament (Thermal Shock?)

It takes time for a filament to heat up. If your PWM frequency is much faster than the thermal time constant of of the lamp, you effectively won't be rapidly turning the lamp on and off, but rather ...
Hearth's user avatar
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2 votes

P channel MOSFET for PWM Peltier control (Arduino)

A P-MOSFET connected as you show it will always be on, regardless of the PWM signal: simulate this circuit – Schematic created using CircuitLab The MOSFET is "upside down." If you ...
JRE's user avatar
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5 votes
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4-pin 12 V PC fan - manual speed control

It looks like you are not interested to control the speed but just set it to always run at full speed. What you describe should work but there is an even easier way because the 4-pin PC fans are ...
Justme's user avatar
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1 vote

How measure fan signal that not seems to the ground isolated?

Sounds like your fan has an open collector output and you need a pull-up resistor to Vcc.
vir's user avatar
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