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Questions tagged [fan]

A device that produces air movement by way of blades or surfaces attached to a rotating motor.

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0
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2answers
8k views

Can a PWM fan be turned on and off with the control pin voltage?

Can a PWM fan be turned on and off through the control pin? Or can it only adjust speed? Is it just a fet that turns the 12V on and off?
4
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4answers
5k views

How can I adapt a 3-pin PC fan connector to a 4-pin connector?

My computer's motherboard uses all four pin fan connectors with no support for speed controlling the older three pin fan connector. The problem is, all the PC fans that I have use a three pin ...
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2answers
590 views

Simple PC fan controller PWM discrete components

Recently I switched some case fans in my pc to find the horror that the new ones were even louder than the old ones. After some quick checks just by eyeing and monitoring on my pc I can confirm the ...
2
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0answers
499 views

What's necessary to properly decouple/filter a PWM-controlled fan from an Arduino?

I've got a small problem I could use some help with. I am using an Arduino to control a cooling system I am building for a DSLR. Primary goals are to use PWM and some pots to control TEC power, as ...
2
votes
1answer
121 views

Good fan speed for solder fumes

I am going to be soldering in an enclosed space, so I am building a fume extractor via ducts. My eventual plan is to have one fan near the vent, and another somewhere near the inlet to help the fumes ...
2
votes
1answer
614 views

What DC fan connector is this?

I’m trying to identify the kind of connector I need for a few DC fans, but can’t track them down on digikey. Pictures attached. Pitch is 2.00mm, wire is 26AWG. The replacement fans I possess have ...
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1answer
1k views

How can I divide a variable voltage in half for a fan (variable load)? [closed]

I have a Peavey PV 2600 amplifier (1800W RMS) that I'm going to use in my home theater, but the 24V 80mm fan is much too loud and noisy. I want to replace it with a silent fan (Noctua NF-A8 PLX), ...
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3answers
194 views

Do fans need to run on DC? [closed]

I recently took apart a wall outlet fan and saw that it works by using the magnetic field created by a coil of wire to spin a piece of metal. I wondered if this runs on DC or AC, and I thought if AC ...
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1answer
11k views

Motor doesn't turn but makes noise [closed]

Motor that I took from electric fan doesn't turn, just makes buzzing noise. I had two fans, took motor from one and when I saw it doesn't work, I opened second one to check if I made something wrong. ...
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1answer
464 views

How to control 220 volts without using relays?

I have a fan in my house, It has an electronic PCB that responds to a remote control. The PCB has a voltage dropping capacitor so, I think it is supplied with a very low voltage such as 9 or 12 volts. ...
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1answer
2k views

Powering a 4-Pin stock CPU heatsink fan with an external power supply

I have scoured this website and the rest of the internet looking for a solution to my particular issue, but as of yet I have not found an answer. If this is a duplicate question I am sincerely sorry, ...
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1answer
4k views

What happens if I reduce the air flow for an exhaust fan?

I'm not very familiar with 220V AC circuits and motors that run on them, so let me explain my question. I'm building a soldering fume extractor for my workbench similar to what is shown in this ...
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1answer
196 views

12 Volt Solar Air conditionair

I saw a post on YouTube where somebody was able to make ice with a 90 watt solar panel, two 12 volt batteries, an ice maker (800 watt spikes) and 1000 watt DC-AC inverter. https://www.youtube.com/...
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2answers
1k views

How to change speed of dc motor using potentiometer?

I want to change the speed of a DC motor(12V,2000RPM) using a pot and operate a table fan(where I've replaced its AC motor with DC).Now the problem is I get a regulated output at o/p of 7812 but not ...
6
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1answer
1k views

Why does my PWM amplitude vary with duty cycle?

I'm controlling a 4-pin PWM fan from a 5V PIC and before going too far I'll say that everything is working fine but I'm just not understanding what I'm seeing on my scope. The fan has a 12V supply ...
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1answer
882 views

PC fan DC adapter power requirement? [duplicate]

I just bought a 120mm deep cool fan with a rating of 12v, 0.07A (70 mA)= 0.84watts Currently I only have a 12v 2.5A (2500mA) DC adapter. I'm a complete noob in electricals...so the question is- Can ...
2
votes
1answer
86 views

Buck regulator to match an analog voltage

In desktop computers, it's common to have headers that control fans with a 0-12V analog output, capable of up to 1A. This works fine for one or two fans, but with more than three fans, you can exceed ...
3
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2answers
3k views

Will 0.16 amp rated fan replace a 0.3 amp fan?

I have a noisy PSU fan (400 watt Coolermaster PSU), It's 120mm and 12 volts. I have found an identical fan which is also 12v, but rated 0.16A, as opposed to the original 0.30A fan. I'm aware PSU ...
0
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2answers
337 views

What possible issues with running a fan inside a freezer?

I need to turn on a fan inside an ice cream display cabinet when the lid is closed, and turn the fan off as soon as the lid is opened. I'm looking for a way to have as little temperature derivation ...
0
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2answers
2k views

Wiring up a computer fan to a normal outlet, without using a computer PSU

Ive got a Rack that is getting abit hot and i would like to cool using fans. Ive checked out units made by Mid Atlantic c.£300 which are really expensive, but have also come across places selling fan ...
2
votes
1answer
2k views

Changing fan Speed of a 4pin PC case fan with a microcontroller

I'm very new to electronic projects, I know the BASICS of circuits (i.e Ohms law, capacitance)but I've never constructed something on my own. For my project I want to take the side fan for my ...
0
votes
1answer
980 views

DC motor speed control: 12VDC 700mA fan motor powered by 7.2Ah sealed lead-acid battery

I am using a 7.2 Ampere-hour Sealed Lead Acid Battery to power a 12V DC motor which is driving a fan, and I need to understand ...
1
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2answers
1k views

How to calculate heat dissipation improvement when adding a fan to the heat sink?

I'm using an LM338 which I want to supply at least 3A @ 20V, with Vin being 35V. I made my calculations and I figured out I'd need a very expensive (for my budget) heat sink so I'm looking for a more ...
3
votes
2answers
1k views

Mosfets cooled with Heatsink and fan?

For my circuit, I have mounted heatsinks to my mosfets to dissipate heat. I have below a crude drawing of how the heatsink/mosfet is placed on the PCB I was thinking to integrate a LM35 to measure ...
0
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1answer
45 views

High Energy Metal Halide Bulb Heat?

I am building a custom box from wood (around 14 inches by 10 inches by 10 inches) to encase 3 high energy Metal Halide Bulbs (400+ watt each). The box will be opened and closed intermittently, ...
0
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3answers
198 views

Two voltage sources - selecting with digital signal

I'm trying to build a fan controller based on Arduino. It will be (at least I hope so) possible to either control with pure PWM or voltage regulator based on buck converter. Now what I'm trying to do ...
0
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2answers
2k views

Controlling fan speed with a rheostat

I just got a rheostat from radio shack to connect to my homemade stir plate. The rheostat looks like: (from here) My question is, how do I set it up? I want to use it to vary the fan speed. I am ...
1
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1answer
64 views

can I wire a ceiling fan to a 4 DP toggle switch?

I want to re-purpose a ceiling fan motor and would like to have each of the three speeds available on their own switch (or position on a toggle). Is this possible? and if so how should I go about this?...
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2answers
2k views

arduino: turn on-off a 12V cpu fan with optocoupler

I wish to use a simple way to turn on-off a 4 wire cpu fan using a digital output of the Arduino board. Since even with PWM=0 the fan works at 30% of the full speed, i have to find a way to cut off ...
2
votes
3answers
13k views

arduino - how to read and control the speed of a 12V - four wire fan?

I want to read the rpm and control the speed of a 12V - four wire fan through Arduino. There are many articles describing the procedure, yet I have some questions. Read Speed: So, 12V and Gnd are ...
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3answers
5k views

What amperage fan is safe to replace my 0.13A fan?

Fan on my wine fridge is buzzing, so I'm replacing it with a CPU or case fan off newegg. Should the replacement fan be rated at more than .13A, or less? I suppose ...
4
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2answers
4k views

Why do we use a diac for triggering a triac?

I mean, Wouldn't it be possible to give a gate pulse on triac directly? I have seen in many phase control application circuits like fan speed control,the usage of diacs to trigger a triac.
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1answer
123 views

Are there any effective estimates for up-rating resistors power capability by adding airflow?

I'm considering using a bank of resistors similar to this: http://www.vishay.com/docs/31842/fve.pdf 300-400 watt "corncob" wirewound resistors. I understand that they can be run over their spec'd ...
2
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4answers
840 views

Operating a 0.08 amp fan using capacitor

I am developing a hot air blower made out of 40w heater, 25mm fan and 12v power supply. I want to be able to keep the fan working in case that the power supply is cut off, so in case the heater is ...
-1
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1answer
167 views

Fan Control using Motor Driver, looking for suitable solutions

I want to control the speed of a fan (which is a 2-phase brushless DC motor). I am currently using a suitable power supply to run the fans. My source is a Data Acquisition device that outputs up to +...
1
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1answer
552 views

Atmega328 resets when I try to turn off an AC fan using relay

I have connected an array of 6V relays to one of the digital pins of my Atmega328 microcontroller via a driver ulN2803. I have connected two lights and one fan to the relays. The light bulbs seem to ...
2
votes
1answer
979 views

is CFM additive?

I currently have a heatsink with 1 (loudish) 1000-1500 CFM fan. If I was to put 2 quieter 500-750 CFM fans on either side of the heat sink, would they effectively push the same amount of air? It is a ...
3
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4answers
5k views

Why do fans keep running after power-off

What is the reason why the fan of many electronic devices, such as video projectors, laser printers or kitchen ovens (have to) continue running after the device has been powered off? It is my ...
1
vote
3answers
8k views

Measuring Current in 12V DC Fan

I am trying to measure the current of a DC computer cooling fan (Intel E18764-001) at various volts. Its rated specs are: 12V 0.20A. Check it out here. So I am suspecting that this is telling me: "...
2
votes
2answers
8k views

Solar panel and 120mm Computer fan

Just before I start description my question, I would like to let you know that I am new at this. I am working on a solar air heater for one of my window. I've been researching and reading up on a lot ...
0
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1answer
604 views

Fan 4-pin connector

My laptop's power supply to the fan gave up and I want to reroute it. My plan is to use power from the USB. And I want to make it clean, with connectors instead of soldering (where applicable). The ...
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1answer
155 views

How can I add a second fan to this circuit? Directly control the fans?

I want to add a a second fan to my laptop. On its mainboard there is just one fan connector but there are also 3 exposed contact points nearby. Could I somehow use them for that? JFAN1 is the exposed ...
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3answers
893 views

12V fan does not work when in parallel but does in series

I am building a food cooler for camping this summer. My plan is to build a thermoelectric cooler that is solar powered. My cooler is looking much like this: including a CPU fan on the hot side and ...
2
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2answers
7k views

Considerations for solar powered thermoelectric cooler with fan

I am building a food cooler for camping this summer. My plan is to build a thermoelectric cooler that is solar powered. My cooler is looking much like this: including a CPU fan on the hot side ...
2
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2answers
2k views

delayed auto off circuit after receiving power (ceiling fan)

I came across this website while doing a bit of research. I've used the stack overflow (programming) version of this site before but this is my first time on the electronics version. I'm looking at ...
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1answer
2k views

Proper configuration of a PWM fan which should be stopped when the controller power is cut off

Recently I am working on a controller to drive a PWM fan (datasheet). I am using a atmega32u4 and it sends a 25khz PWM signal to the fan and it's working well. I want the fan to be off when I cut the ...
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3answers
3k views

Analog Fan control via PWM

I want to control a fan using analog voltage instead of PWM. I have a PWM signal from MCU. I want to use a low pass filter to convert this to analog, so 0 to 3.3V based on PWM duty cycle. This will ...
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2answers
672 views

Solar panel and little computer fan

OK here is the spec: Solar Panel 4"x6" 200mA 7.2v Fan small : 20x10mm, 12vdc, 60mA, 2.17cfm medium : 40x20mm 12vdc, 140ma, 8.28cfm What I'd like to do, is to be able to run the fan hook to the ...
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1answer
798 views

Monitoring a fan with 2800 RPM with a Siemens 27-226 PLC

I have a fan that rotates at 2800 RPM. I need to make sure that the fan is operating. I need to monitor the fan. It has an output that gives a signal 2 times per rotation so it's 5600 pulses which is ...
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0answers
224 views

Gate resistor needed for this circuit?

I'm making a simple circuit for driving a fan based on temperature. Given that the LM339 needs a pull up (R5) do I need to put a series resistor in between the LM339 output and the gate of the ...