Is it possible to adjust the lowest fan speed setting in control box? - Page 1
Forum section: electronics / beginners

author: saflyfish
author_rank: Contributor
timestamp: September 09, 2025, 08:35:48 am
content: Hi allMy ceiling fans lowest speed setting (1) is way too fast.Is there a way to lower that fan speed setting?See attached inside of control box

author: Ian.M
author_rank: Super Contributor
timestamp: September 09, 2025, 09:17:57 am
content: No. Everything is handled by the circuit in the potted module so there is no access to hack it. Also it looks too small to be switching in dropper capacitors so its almost certainly electronic speed control, and even if you had the bare PCB accessible, they can be very hard to hack.It may be worth investigating if your fan is actually reversible, as switching it to blow upwards gives a much gentler air flow in the room. Unfortunately if you want a reversing switch at the wall control, you typically need an extra wire going to the fan.

author: saflyfish
author_rank: Contributor
timestamp: September 09, 2025, 09:34:24 am
content: thank youWhat if i purchased another control box?

author: Ian.M
author_rank: Super Contributor
timestamp: September 09, 2025, 09:55:33 am
content: Maybe. If you get a fully variable one it may be easier to hack, or even have a low enough minimum speed as-is. However this sort of device is often based on a microcontroller (rather than easily hackable analog circuits) nowadays, and the lower limit will typically be set in the firmware, which is almost invariably protected, so even with the right hardware and software toolchain, you cant read it out to attempt to modify it.If you can find an 'old skool' control box that switches in different run capacitors in series with the fan to control the speed, then you'd have a good chance of getting what you want by changing the lowest capacitance one to an even lower value.

author: CaptDon
author_rank: Super Contributor
timestamp: September 16, 2025, 02:12:45 pm
content: There are 'fan motor' dedicated solid state controllers which can go from 0 to 100%. Fan motor controllers look like lamp dimmers but operate differently due to the inductive reactance found in motors.

author: saflyfish
author_rank: Contributor
timestamp: September 16, 2025, 02:27:31 pm
content: So would I replace the pictured control box with one of these fan controllers?

author: CaptDon
author_rank: Super Contributor
timestamp: September 18, 2025, 09:52:48 pm
content: It looks like you could. In your picture those taps on the switch do not appear to be winding taps from the motor. They appear more like a selection of fixed value resistors on a solid state controller and could most likely be replaced by a ceiling fan style controller. Ceiling fan motor controllers are usually a bit more expensive and sometimes a bit heavier or larger than a typical lamp dimmer device.

author: saflyfish
author_rank: Contributor
timestamp: September 19, 2025, 05:33:54 am
content: Ive done a google search and cant really find something suitable.Would you mind sending me a link or point me to a website that has one of these controllers.It would be easier if i saw a pic lol...You could DM me

author: CaptDon
author_rank: Super Contributor
timestamp: September 20, 2025, 06:12:21 pm
content: Sadly, I see you are not located in the U.S., We have a national chain of stores here called Lowes. They have the controllers for ceiling fan motors in the isle with the ceiling fans. Lamp dimmers are typically under $12USD while Fan Motor controllers are typically over $18USD although both controllers look very similar. Some of the motor controllers need a deeper box to mount in. Maybe you can simply search online for 'ceiling fan motor speed controller'.