# EMU Black PWM Fan Control - H-Bridge High Side Trigger

**URL:** <https://community.ecumaster.com/t/emu-black-pwm-fan-control-h-bridge-high-side-trigger/4199>\
**Category:** EMU BLACK / CLASSIC\
**Created:** [August 5, 2025, 7:32pm UTC](https://community.ecumaster.com/t/emu-black-pwm-fan-control-h-bridge-high-side-trigger/4199 "2025-08-05T19:32:55Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![DevOnBoost](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/devonboost/32/6285_2.png) [@DevOnBoost](https://community.ecumaster.com/u/DevOnBoost)\
**Post date:** [August 5, 2025, 7:32pm UTC](https://community.ecumaster.com/t/emu-black-pwm-fan-control-h-bridge-high-side-trigger/4199/1 "2025-08-05T19:32:55Z")

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Hello Everyone!

I’ve been tinkering with V3.054 on the EMU Black and was wondering how I could achieve the following:

I have a 16 inch Proform brushless fan that uses Positive (High Side) PWM control. 3 wires come from the fan, one wire is +ve PWM. Other 2 are heavy gauge power and ground sources.

How do I configure my H-Bridge to control that fan directly?

- I see no option to ensure that I am sending a 12V PWM signal to that control wire on the fan.
- So far, I am using the PWM Table 1, with CLT on the x-axis and VSS on the y-axis.
- Is there an option I’m missing where I can set the polarity of H-Bridge?

Thanks!

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**Author:** ![FloorItGarage](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/flooritgarage/32/61_2.png) [@FloorItGarage](https://community.ecumaster.com/u/FloorItGarage)\
**Post date:** [August 7, 2025, 6:55am UTC](https://community.ecumaster.com/t/emu-black-pwm-fan-control-h-bridge-high-side-trigger/4199/2 "2025-08-07T06:55:49Z")

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Inverting the H bridge output will change it from low side to high side. However if memory serves PWM outputs only work low side.

A pull up to 12V and inverting the table may work for this.

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<div class="post-metadata">

**Author:** ![DevOnBoost](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/devonboost/32/6285_2.png) [@DevOnBoost](https://community.ecumaster.com/u/DevOnBoost)\
**Post date:** [August 7, 2025, 12:45pm UTC](https://community.ecumaster.com/t/emu-black-pwm-fan-control-h-bridge-high-side-trigger/4199/3 "2025-08-07T12:45:32Z")

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Thanks for the suggestion! You’re right. I’ve been researching the topic and the consensus seems to be exactly that. I’ll probably start with a 10k ohm pull up. Also could be used on any AUX or H-Bridge output.

Cheers!