12V Micro fan to USB-C not working - Page 1
Forum section: electronics / beginners

author: jbs
author_rank: Contributor
timestamp: February 27, 2024, 08:51:50 pm
content: So I cut a male to male USB-C cable in half and connected the positiv and negativ of my fan to the red(+) and black(-) of the USB-C respectively.I cut off the green and white (data) cables and made sure that nothing came in contact (electrical tape).I was following the steps explained in this video:However, when I plug the USB-C to a power source (power supply from my macbook pro, or power supply from my gopro, or cigarette lighter outlet in my car) my fan does not move.Q: Why doesn't it get 9V from the USB-C PD, or at least 5V if it was no PD cable and what can I do to make it work?The data of my micro fan (article nr. MF25101V2-1000U-A99):12 V0,36 W25x25x10 mm3 (dimension)Thanks in advance,Joël

author: electr_peter
author_rank: Unknown
timestamp: February 27, 2024, 09:01:25 pm
content: Most USB-C PSU ports expect to see specific conditions on data lines (5kOhm) before enabling power. The simplest solution is to get USB-C decoy boards for specific voltage.

author: radiolistener
author_rank: Super Contributor
timestamp: February 27, 2024, 09:03:14 pm
content: by default USB provides 5V, if you want more you're needs to request it from power supply with PD/QC protocol over USB data line.You can use PD trigger module for 12V to get 12V from USB PD/QC charger.Like this one:https://www.aliexpress.com/item/1005003828144045.html

author: jbs
author_rank: Contributor
timestamp: February 27, 2024, 10:03:43 pm
content: Quote from: electr_peter on February 27, 2024, 09:01:25 pmThanks for your reply. However, why does it work without a trigger module in the video? When I plug it into my laptop, it doesn't.

author: janoc
author_rank: Super Contributor
timestamp: February 27, 2024, 10:06:28 pm
content: I suggest you read this series of articles:https://hackaday.com/series_of_posts/all-about-usb-c/It explains what you have to do and how things work. Cutting up a cable is not enough - you must put in those pull-down resistors otherwise the upstream port has no idea that you have connected anything to it and won't enable power. Some cheap chargers and non-standard compliant stuff may have the 5V on all the time but that isn't something you can rely on - as you have discovered. Specifically laptop ports that both can't deliver a lot of current and support various other things than just powering stuff from them/plain USB need to be 100% sure that the connection is safe and won't damage anything before enabling power. That's why the system is designed the way it is.This is quite different from the old USB A!

author: electr_peter
author_rank: Unknown
timestamp: February 27, 2024, 10:37:05 pm
content: Quote from: jbs on February 27, 2024, 10:03:43 pmVideo shows USB-A connection - it is simpler with 5V enabled by default (limited to 100mA without negotiation if implemented properly). USB-C connection is more complicated.

author: radiolistener
author_rank: Super Contributor
timestamp: February 28, 2024, 06:27:09 pm
content: Quote from: jbs on February 27, 2024, 10:03:43 pmPD/QC chargers expecting voltage request with data packets over USB data line. If you don't request voltage, it just provide you with 5V. Laptop has PD trigger inside, this is how it requests high voltage from PD/QC charger. It cannot be done with resistors. It requires to send/receive datapackets in order to implement PD protocol to request proper voltage from charger.In short it works in the following way:1) Device is connected to charger2) Charger provides 5V by default3) Device send request packet to get supported charge protocols from charger4) Charger responds with a list of protocol that it supports5) Device requests one of supported voltage6) Charger switch voltage to requested one (if it supports it)Also note that a fan can be designed for different voltage. Some fan is designed for 5V and can work from USB with no needs for additional circuit. But if your fan is 9 or 12V, you're needs PD trigger module, as I mentioned before.You can use this PD trigger module, it allows to setup desired voltage with micro switches:https://www.aliexpress.com/item/1005003828144045.htmlBut note, USB port should support PD charge and should support requested voltage in order to provide voltage that you setup on PD trigger. Usual USB port with no PD protocol support cannot provide more than 5V.Also note that most of 24W PD chargers with USB-A port don't support voltage above 12V.