[SOLVED] Can you power pc fans from a 5v wall plug?

[SwordOfSierra]

I plan to do some experiments with pc fans so I’m buying some cheap fans off Amazon. Because they are cheap, I’m concerned about the cables shorting or melting. As such, I don’t want to plug into my PSU, and was wondering if a 5v wall plug such as this one (https://www.amazon.com/dp/B017TXGM4I/ref=cm_sw_r_cp_api_glt_fabc_RWQDC7ZWAVFP6VVEGGVX) with a usb to 3-pin adapter will work to power fans

 

[InvalidError]

Most fans will start reliably at 7V, many will work on 6V. Down to 5V though, the bulk of them either won't work at all or require a push to start.

As mentioned by others previously, fan speed will vary with voltage and will be very slow at 5V. I use an adjustable DC-DC converter to run my PC's front fans at 6.5V, enough for them to start reliably and spin fast enough to generate meaningful airflow through my case's intake filter without generating too much noise.

 

[CountMike]

Not necessarily. As long as the base control variable is constant, any data gathered can be compared to that and won’t affect percentages

With very small air flow rates other factors account for more percentage in the results. Also must take into account that such fans regulate speed by varying voltage and with it power of the motor not directly but because of air resistance (not able to turn as fast) so it would be very difficult to have constant speed.

 

[lvt]

Most fans will start reliably at 7V, many will work on 6V. Down to 5V though, the bulk of them either won't work at all or require a push to start.

As mentioned by others previously, fan speed will vary with voltage and will be very slow at 5V. I use an adjustable DC-DC converter to run my PC's front fans at 6.5V, enough for them to start reliably and spin fast enough to generate meaningful airflow through my case's intake filter without generating too much noise.

I see your point, back on the early days, in order to reduce the fan noise, I had to mod the Molex connector to have 7V instead of 12V so that the fan will run more silently. A DIY switch can be made to select fan speed by using 7V or 12V.