+kuyanatnatdkrx7 Adam savage said that on mythbusters

+Nathan Healy On what episode ?

one of the earlier one's I think. He was probably quoting him.

that's true, Adam Savage said that

mythbusters refrence

@Ξxodus for real?

Lol

Lol

😂😂😂😂😂👍👍

🤣🤣🤣🤣

well, its still funny. Also, most germans do not pronounce it van because "fan" is used in the context of football fan or something similar in german as well and it is not pronounced "van".

Lol

@Markus Schnepf I am not sure what my intention with that comment was(check the timestamp) But i believe i meant that germans would know how to pronounce it since they use that word for football fans and such. You can't say no german though, he is german and pronounces it "van".

In serious

BigClive doesn't use music :) . Though not a professor per se, but he does know his stuff.

This is also why you should know that Darth Vader was his fater from the first movie.

“Volkswagon” lol. VOLKSWAGEN!

@@benjaminfauchald2990 wait what how how no what

That reduction can also be achieved by using much higher power (.5 1 or even 2 W) resistors...in some cases PWM might not work and a resistor is, unfortunately the way to go and you will need those high resistors. I'm impressed that his didn't start smoking seeing how hot they were actually... From work I managed to score 3 16 Ohm, 60W resistors (no clue what they were in, but oof they are beefy).

In case of putting a potentiometer between the device and the voltage source, the heat buildup in the resistor that is a potentiometer is based on 2 things: the amount of voltage difference you want to create (in your case: how fast the fan is spinning) and the amount of current this device draws. The reason his quarter of a Watt set of resistors became flaming hot in the case of the LED strip is because there was a stupid amount of current (up to possibly around a full ampère) running through them all while also trying to limit some current from reaching the LED's so they would not shine as bright. Trying to regulate current/voltage with a resistor means there will be power that has to be dissipated in a way, in this case by putting all the power we don't want the device to use into an electronic part that has to get rid of the excess power by converting it to heat. In case of low-current devices this will typically not be a thing for small variations, but the bigger the difference between the device and voltage source, the more heat the resistor will start producing. Even if 0.25W resistors might be fine for a small variation, they might start to become reasonably hot when you slow the fan down more, because the power not used by the fan will have to go somewhere, in this case by being converted into heat. Sometimes you can feel this, sometimes you can't but the process is basically still there, just not detectable.

The POV Display has been on my to do list for quite some time. It will happen soon.

@@greatscottlab so it did finally happen! :) Loved it!

Some PWM circuits will require a big value potentiometer in order to see a big difference in output. One that I know uses a 100Kohm one, with a 10K one the difference is minimal, noticeable, but minimal (in my case it's used to control the backlighting of buttons in a dashboard-simrig setup).

A power transistor or a mosfet that you feed the output from the PWM circuit.

You can use regular (BC547) low-power transistors for driving them as variable resistors. That's how I use them in a dashboard-simrig build for controlling the gauges from an Arduino. Low duty cycle/PWM frequency (I have yet to look at the output of a PWM signal of an Arduino with a scope, I have seen the Tone one) means the gauges shows a low value, and a higher PWM value means the gauge shows a higher value :) . You do need to use a fairly high value resistor on the base of the transistor in order to do this, you want to drive them like a variable resistor after all (I think my setup uses 10K).

you're probably using a log pot - use a linear one

@@benkrege2135 No, that's not it. Most motors (especially cheaper, usually brush-ones) will have a stall voltage limit which will cause the voltage supplied to be insufficient for enough current to make it turn and have another successful turn be initiated. A linear pot will probably then show the same behaviour, except it will show it at a different point when rotating the axes of said potentiometer. With PWM however, the voltage provided stays the same, but not the time it is applied. If the motor wants to turn because of the higher voltage, it might see a small amount of movement and if the frequency of the PWM signal is high enough, it will keep functioning at much lower speeds: the voltage required to push current through the device is, after all, still there.

Bob Bennem I am familiar with the project. And I really like the idea. But instead of building a new lamp I would "hack" an existing one to use LED lights and the dimmer circuit.

Mauricio Ferrazzi lmao Over my head too.

***** ELV DPS 7000

GreatScott! How much did it cost?

+Mandragoras google it you fool! lol

Lightning555 I did, you fool, but google won't tell me. It's either a rare or old model. Most results are in german and google translation is just atrocious.

Forget watts in resistor calculations. Depending on the amount of current you will have to limit the fan to in order to reach a 25% to 50% reduction in speed, you will have to try out multiple resistors. Let's for simplicity say that in order to reduce it's RPM by 25% we need to reduce voltage an equal amount (which obviously is not how things work, but OK). Just for the sake of simplicity we also consider the resistor to be a perfect electronic part with no imperfections, and in order to reach the reduction, we can reason that at normal operation, the fan uses 19,2W of energy (12V x 1.6A). In case of a fan reduced in speed by 25%, we end up on (roughly) 14,4W (9V x 1.6A). That means that almost 5W's of energy (which usually is much more than people realize it is) will have to be going somewhere, which in this case will be a heavy, expensive 7.5W resistor (you could use 5 but it will get quite warm due to being on the exact limit of it's power dissipation).

Mind the fact that my electronics experience is limited to soldering a couple (literally, if I remember right) of kits. Once you get the mains to 60V and rectified, this seems to be a job of a step-down regulator. A full Arduino MC might be too much for the job, but if you find uses for the other pins of it (like a fancy light show⸮) it might be simpler overall.

+iakov Jack you dont. potentiometer for LED is terrible. use pwm