18Views4Replies

Author Options:

Help wth a 12v DC circuit Answered

Hello all

2 Questions please

I am working on a hobby project and I am needing to hook a 12v computer fan (200mm) which is 0.3A max...up to a Turnigy 5.0 Li-Po battery. The battery is 7.4v, 30-40c discharge, 5000mAh. I have ordered a DC to DC adjustable voltage "step-up" converter to increase the output to 12v (I am hoping this works). (Q1) - how (if at all) do I limit the output amperage to 0.3A without burning up the fan motor.

The fan is going into a cosplay set of foam armor (to help keep some air flow going to try to keep semi-cool) and I am hoping to be able to run the fan for about 3hrs. If I can accomplish the above, (Q2) - how long might the fan run?

Attached is the "step-up" I ordered...

Discussions

0
None
Downunder35m

11 days ago

You will notice the fan still runs on 7.4V or below.
With the step up converter you can literally adjust the fan speed but don't go above 15V.
No need to do anything with the current as the motor(s) will only draw what they need.

0
None
Jeepguy001

12 days ago

Thank you very much for responding :)

0
None
MR_instruct

13 days ago

Regarding Q2 - the fans is 12v at 0.3 A so it should last at least 10 hours on a fully charged battery assuming 500 ma needed due to the converter.

0
None
MR_instruct

13 days ago

You do not need to add any current limiting. Just set the power supply for 12 volts and the current will be automatically correct. That is how it works in a computer fan also.