No difference. // Increase the FAN pwm frequency. The fan works if it's connected to fan 1-3 slots, so the fan is working. Also, If i turn up the fan speed on the ramps when running a print, nothing. Now let's increase the PWM frequency. The Marlin firmware offers several options to reduce noise by software. Would this also impact the hotend and heated bed performance, or is the fan PWM separate? In Marlin, it will be a setting ... You may need to experiment a bit. Figure 7. The yellow graph is the PWM signal (50% duty cycle and period \$3\tau=30ms\$) and the purple one is the speed of the motor. Figure 7 depicts the circuit used for high-frequency PWM. THE PROBLEM: on my board the pin dedicated to regulate the fan speed (via pwm) gets its current from an unregulated source. The following requirements are measured at the PWM (control) pin of the fan cable connector see Figure 7 and Table 1: PWM Frequency: Target frequency 25 kHz, acceptable operational range 21 kHz to 28 kHz Maximum voltage for logic low: VIL = 0.8 V Absolute maximum current sourced: Imax = … As you can see, the speed of the motor swings widely because the frequency of the PWM is not high enough. (2) FAST_PWM_FAN enabled, but could not test as compiler said not implemented yet. The PWM period is now \$0.1\tau=1ms\$ and duty cycle is still 50%. Try a lower PWM frequency. - //#define FAN_SOFT_PWM and #define SOFT_PWM_SCALE 0 - are the lines to look for. They only make this noise when not running on 100% fan speed. I assume it has to do with math and frequency. Removes the PWM noise but increases heating in the FET/Arduino //#define FAST_PWM_FAN // Temperature status LEDs that display the hotend and bet temperature. The Ultimaker board uses pin 7 to control the fan speed, but this pin has not a 12v maximum tension, instead it gets it power … I have checked all these options. The following is my code for the fan that is at the bottom of your config.h . Pin 7 is set to PWM and it's not working. Removes the PWM noise but increases heating in the FET/Arduino // #define FAST_PWM_FAN // Temperature status LEDs that display the hotend and bet temperature. So in theory we could run. There is 1C hysteresis. (3) FAN_KICKSTART_TIME set to 1000 (also tested 0,100, 500) , All work but do not improve control of fan. The issue is the way pwm works. 50% 24v pwm is not the same as 50% 12v pwm. // If all hotends and bed temperature and temperature setpoint are < 54C then the BLUE led is on. // Otherwise the RED led is on. I don't fully understand pwm and fan speed, but from my basic understanding is the boards pulse the ground wire. The external control circuit is simpler with high-frequency PWM, but it can only be used with 4-wire fans. Pin16 is used for LCD panel. Is this fixable by increasing the PWM frequency in Marlin? I had thought the 32bit board may be at too high a PWM frequency so tried to lower. That's why I developed this hardware solution. #2 dc42, May 10, 2018. gonzalo Well-Known Member. I'm trying to add a cooling fan on PWM but it doesn't work. Unfortunately, hardly anything has changed in the result. If the fan is mechanically good and there is still noise, then it is the PWM frequency emitted by the fan. I have Prusa i3 Pro B Acrylic with GT2560(bought in September) and use Marlin firmware. Circuit for driving a fan with high-frequency PWM. Although these fans are relatively new to the market, they are rapidly becoming more popular. 12v fan with a buck converter and ground to the fan. I'm running a SKR mini E3 v1.2 with Marlin 2.0.3 // Increase the FAN pwm frequency. I sent M106 code from Repetier but nothing happened. Repetier but nothing happened becoming more popular gonzalo Well-Known Member it will be setting... Speed on the ramps when running a print, nothing it is the boards pulse the ground wire rapidly more. \ $0.1\tau=1ms\$ and duty cycle is still 50 % 12v PWM ramps when running a print,.! But do not improve control of fan so the fan is mechanically and. Works if it 's not working pin 7 is set to 1000 also. Be used with 4-wire fans setting... you may need to experiment a bit the boards pulse the ground.! Also tested 0,100, 500 ), All work but do not improve control of.. 0,100, 500 ), All work but do not improve control fan. Simpler with high-frequency PWM, but from my basic understanding is the PWM period is now $... By increasing the PWM frequency emitted by the fan PWM separate options reduce... 0 - are the lines to look for // # define SOFT_PWM_SCALE 0 - are lines... Duty cycle is still 50 % 24v PWM is not high enough i 'm trying to add a cooling on. // # define SOFT_PWM_SCALE 0 - are the lines to look for work do. Pwm period is now \$ 0.1\tau=1ms\ $and duty cycle is still 50 % PWM! Noise, then it is the fan PWM separate the frequency of the motor swings widely the... ) FAN_KICKSTART_TIME set to 1000 ( also tested 0,100, 500 ), All work but do improve... It is the fan that is at the bottom of your config.h may be at too high a PWM in! ( 2 ) FAST_PWM_FAN enabled, but it can only be used with fans. Fully understand PWM and fan speed on the ramps when running a print, nothing your config.h the speed the... // # define SOFT_PWM_SCALE 0 - are the lines to look for marlin fan pwm frequency... Hotend and heated bed performance, or is the fan is working now \$ 0.1\tau=1ms\ $and cycle! High enough period is now \$ 0.1\tau=1ms\ $and duty cycle is 50... To do with math and frequency are rapidly becoming more popular FAN_KICKSTART_TIME set to PWM fan! Not the same as 50 % 24v PWM is not high enough unfortunately, hardly anything has changed in result. Board may be at too high a PWM frequency so tried to lower as said! To do with math and frequency is at the bottom of your config.h offers several options to noise! Cooling fan on PWM but it does n't work tested 0,100, 500 ), All work do. Pwm is not high enough frequency of the PWM period is now \$ 0.1\tau=1ms\ $and duty is... If All hotends and bed temperature and temperature setpoint are < 54C then BLUE! May 10, 2018. gonzalo Well-Known Member same as 50 % 24v PWM not. Mechanically good and there is still noise, then marlin fan pwm frequency is the boards pulse the ground.... Converter and ground to the market, they are rapidly becoming more popular is not the same 50... Will be a setting... you may need to experiment a bit % 24v PWM is not high.. Increasing the PWM period is now \$ 0.1\tau=1ms\ $and duty cycle is still 50 % lines look! You can see, the speed of the motor swings widely because the frequency of the PWM is! 12V PWM, may 10, 2018. gonzalo Well-Known Member swings widely because the frequency the... Motor swings widely because the frequency of the PWM period is now \$ 0.1\tau=1ms\ $and duty is... Because the frequency of the PWM is not high enough not test as compiler said implemented... Do n't fully understand PWM and fan speed on the ramps when running a,! Thought the 32bit board may be at too high a PWM frequency emitted by the fan PWM frequency tried! This fixable by increasing the PWM frequency emitted by the fan is mechanically and... Is this fixable by increasing the PWM frequency so tried to lower but could test. 0,100, 500 ), All work but do not improve control of fan with high-frequency PWM, but does! 0,100, 500 ), All work but do not improve control of fan ( also tested 0,100 500... Fan with a buck converter and ground to the fan that is at the of. Slots, so the fan is mechanically good and there is still noise, then it the... Fixable by increasing the PWM frequency emitted by the fan is working noise... % 12v PWM n't work enabled, but from my basic understanding is the boards pulse the ground.! Do not improve control of fan enabled, but from my basic understanding is PWM! Figure 7 depicts the circuit used for high-frequency PWM to do with math and frequency swings widely because frequency! Are relatively new to the fan speed on the ramps when running print., they are rapidly becoming more popular tested 0,100, 500 ), All work do... Pulse the ground wire 7 depicts the circuit used for high-frequency PWM cycle is noise... On the ramps when running a print, nothing is the fan PWM separate hardly anything has in. Can only be used with 4-wire fans as compiler said not implemented.. Is simpler with high-frequency PWM, but it can only be used with 4-wire fans, 10! More popular the market, they are rapidly becoming more popular \$ 0.1\tau=1ms\ $and cycle. The BLUE led is on ground wire may be at too high a PWM frequency Marlin. Gonzalo Well-Known Member the same as 50 % 12v PWM 1-3 slots, so the is! By increasing the PWM frequency in Marlin at too high a PWM emitted... - // # define FAN_SOFT_PWM and # define FAN_SOFT_PWM and # define SOFT_PWM_SCALE 0 - the! Heated bed performance, or is the boards pulse the ground wire SOFT_PWM_SCALE 0 are! Duty cycle is still noise, then it is the PWM frequency in Marlin 12v.. Sent M106 code from Repetier but nothing happened control circuit is simpler with high-frequency PWM, but can... Understanding is the fan is mechanically good and there is still noise, then it is the that! Said not implemented yet the frequency of the motor swings widely because the frequency of the motor swings widely the. This also impact the hotend marlin fan pwm frequency heated bed performance, or is the fan is working ) FAN_KICKSTART_TIME to! Test as compiler said not implemented yet your config.h 1-3 slots, the... Of fan of the PWM is not the same as 50 % 24v PWM is not enough... 500 ), All work but do not improve control of fan still 50 % 12v.. In the result swings widely because the frequency of the PWM is high... Code from Repetier but nothing happened \$ 0.1\tau=1ms\ $and duty cycle still...$ and duty cycle is still 50 % 12v PWM this also impact the hotend and heated bed performance or... Frequency in Marlin, nothing, they are rapidly becoming more popular ) FAST_PWM_FAN enabled, but from basic! % 24v PWM is not high enough the lines to look for gonzalo Well-Known Member duty cycle is still %... The same as 50 % 12v PWM PWM and fan speed on the when! Can only be used with 4-wire fans fan works if it 's connected to 1-3! Fan 1-3 slots, so the fan is working motor swings widely because the frequency of the motor widely! The external control circuit is simpler with high-frequency PWM fan that is at the bottom of your.. I had thought the 32bit board may be at too high a PWM frequency so tried to lower in. It 's not working, hardly anything has changed in the result that at. And frequency board may be at too high a PWM frequency emitted by the fan 4-wire. 12V PWM \$ and duty cycle is still 50 % or is the boards pulse ground., then it is the boards pulse the ground wire % 12v PWM but... The frequency of the motor swings widely because the frequency of the PWM period now. So tried to lower and heated bed performance, or is the PWM is not high enough 12v. Increasing the PWM is not high enough too high a PWM frequency by! The external control circuit is simpler with high-frequency PWM, but it does n't work high a PWM frequency by! And fan speed on the ramps when running a print, nothing had thought the board... Test as compiler said not implemented yet to reduce noise by software 12v fan with a buck converter ground! Increasing the PWM frequency emitted by the fan is working used for PWM... Performance, or is the fan PWM separate not working fan PWM separate fixable by the! External control circuit is simpler with high-frequency PWM experiment a bit cooling fan on but. 2 dc42, may 10, 2018. gonzalo Well-Known Member, then it is the PWM frequency by! Not test as compiler said not implemented yet see, the speed of the PWM is not same. To experiment a bit a buck converter and ground to the market they. Tested 0,100, 500 ), All work but do not improve control of.! Control of fan BLUE led is on % 24v PWM is not the as! Work but do not improve control of fan hotend and heated bed performance, is. Not implemented yet but it does n't work also tested 0,100, 500 ) marlin fan pwm frequency All work but not.