Start-up and shut-down voltage
This chapter should be read with caution and attention as long as the fans are not purely analog, i.e. DC-controlled fans with 3-pin connection. The PWM control electronics almost always stand in the way of clean voltage regulation and it is therefore also not advisable to regulate PWM fans via voltage. Nevertheless, we have also carried out this measurement for all models, regardless of whether they are DC or PWM fans, because even strange results say a lot about the control electronics and the use as a DC-controlled fan. Of course there are also laudable exceptions like the Fractal Prisma AL-12 PWM ARGB , but more about that in a moment.
But first, to be on the safe side, we check the maximum speed at 100% PWM and compare it with the datasheet. The fan manages the specified data absolutely precisely even after the 24-hour run-in. Of course, there is usually a smaller series dispersion in the game, but not here, This fits so really perfect.
In today’s DC test, we see that the fan only starts up with voltages from about 4.5 volts, while the fan from be quiet! requires at least 3.2 volts. Furthermore, the Fractal Prisma AL-12 PWM ARGB interestingly achieves PWM and DC controlled maximum speed and sufficient throughput as well as static pressure. Pure voltage regulation is definitely within the realm of possibility, especially if you want to go below the PWM minimum speeds.
The approximately 550 rpm PWM-controlled from the measurement (see curves below) are certainly still a normal value for such a fan, although not the optimum in practice. DC-controlled, the fan can be further reduced and even switched off – so a fan stop is also possible in a roundabout way. The quite high voltages are due to the electronics, but bearable and minimize in return the current load at the header, which is usually around 1 ampere.
Start-up and shut-down behaviour
The following measurement curves once again illustrate the very different behaviour. Let’s look at DC control first. Here, a proud 269 rpm are reached, below which the engine comes to a powerless standstill. So DC control is definitely an option, even if the switch-on pulse must be at least 441 rpm.
With the PWM protocol, we can also see the fan running very well because there is no minimum speed. The rest then reflects the data from the bar chart. Only this lower speed is above what the data sheet promises.
Power consumption
This value is amazingly low and really exemplary. Consider that 5 fans alone would not draw 10 watts together. This is absolutely no problem, also for the motherboard and the cables. So, from that point of view, DC control is a clever alternative, but it is not advertised that way. For whatever reason.
15 Antworten
Kommentar
Lade neue Kommentare
Veteran
Urgestein
Urgestein
Veteran
Urgestein
1
Urgestein
Mitglied
Urgestein
Mitglied
Urgestein
Mitglied
Urgestein
Mitglied
Urgestein
Alle Kommentare lesen unter igor´sLAB Community →