How to control fan speed based on load (not temperature)?

Question

Electronics

There is a 12v power supply for about 200w, it feeds the rgb led strip. Depending on the chosen color of the tape, the power consumption can vary by 3 times (some or all of the diodes are on) - in order to be a little safe, a computer cooler is attached to the power supply.

I wonder if there is a way to control it depending on the load coming from the power supply? The backlight is turned off 90% of the time, but the PSU is always connected to the network - accordingly, the cooler is spinning and creates a little noise. I know that you can buy a controller board from ali , but they work depending on the temperature of the sensor, not the current (or I could only find one).

If there is a ready-made solution (on the same Ali) - it would be best. In other cases, it is interesting whether it is even possible to implement a device that is connected in series with the load and controls the speed of the cooler depending on the flowing current. I almost don’t understand electronics, it would be interesting to know at least in which direction to google.

Answer 1

put a shunt and read the value of the current consumed from it, use this signal to control the fan.
it just doesn't make sense.
the temperature of the "power supply" is proportional to the power consumed (with small delays for heating / cooling the radiator)

Answer 2

I almost don’t understand electronics, it would be interesting to know at least in which direction to google.

Then the easiest way is a ready-made solution with temperature control of the PSU (for example, the radiator of the output rectifier).
And so - to control (for example - with the simplest RC chain) the duty cycle of the pulses (duty cycle), which is proportional to the load and adjust the fan speed using it.

Answer 3

1. The idea of ​​​​blowing in terms of power is, in my opinion, erroneous, if the goal is to reduce the temperature, then you need to rely on temperature. The board according to the link is exactly what you need, it will turn on the fan if it is really needed.
2. If the power supply requires additional airflow - the power supply is incorrectly selected, it would be wiser to supply the correct power supply.