When to use fan

[adwnis123]

I have build a circuit on epoxy protoboard with 1,5mm^2 wires. When the circuit is stressed it can consume 5 Amps@12 Volt. Generally I have no experience on that much currents. I am thinking of using a fan for cooling. What is your opinion??

 

[barry]

My opinion is: you may need a fan; you may not need a fan; you may need a water-cooled heat exchanger; you may need to use liquid nitrogen; you may need a fire extinguisher.

Unless you give us more information, you're just going to keep getting stupid responses.

For starters, how much heat are you dissipating? How much heat can your mysterious, undefined circuit withstand? What's your ambient temperature?

 

[KlausST]

Hi,

To add what Barry wrote:

Where are your calculations? You need to (learn to) do them on your own. It's not that difficult.

1.5mm^2 copper wire has a resistance of about 1.2mOhms per 10cm.
On 5A this means a power dissipation of about 30mW. You won't recognize the temperature rise.
I see no need for a fan. ...at least without additional informations

Klaus

 

[BradtheRad]

5 Amps@12 Volt

60W. It can be split among various devices yet not generate damaging heat. Does your finger burn when you press on a component? Perhaps it needs a heat sink. It may be sufficient to attach metal fins, to draw away heat and be cooled by air.

Or else the power supply is a common source of heat. Is that the part you're concerned about?

 

[adwnis123]

60W. It can be split among various devices yet not generate damaging heat. Does your finger burn when you press on a component? Perhaps it needs a heat sink. It may be sufficient to attach metal fins, to draw away heat and be cooled by air.

Or else the power supply is a common source of heat. Is that the part you're concerned about?

I am asking about both power supply (220V to 12V/6A) and the end circuit.

 

[d123]

Hi,

If you use a fan for enclosure (whole circuit) cooling, define for yourself what temperature is the 'wrong' temperature and why you believe it is, and where it is best placed for most effective results.

You really ought to do PD calculations for each part that may get very/too hot and affect nearby component functionality or reach its own maximum junction operating temperature (or stuff that might melt - improbable, but still...). At least rough calculations. You may not need one at all or really need one on at certain moments.

Fans go well with a hysteresis range to avoid annoying constant on/off behaviour, such as on at 50°C and off again at 40°C or whatever, making the circuit larger, unless the fan is on all the time.

Fans have a cubic feet air flow parameter I didn't understand with first two I bought but is important when comparing products (in case you hadn't noticed that aspect).

They are a good feature to add when you have the additional current to spare but only if really necessary, imo.

 

[barry]

I am asking about both power supply (220V to 12V/6A) and the end circuit.

Again, WHAT IS YOUR CIRCUIT? Do you think a 60Watt light bulb needs a fan? How about a 0402 resistor dissipating 60 Watts? Why do you think a 60 W power supply might need an additional fan? If it does, it wasn’t designed properly to begin with.

 

[crutschow]

Really need to know exactly what component(s) are dissipating that power to give you a good answer.

 

[adwnis123]

I supply a CPU with peripherals for demanding image processing

 

[KlausST]

Hi,

Look at the posts. Several people try to help, gave informations, asked questions.

And all you respond are a handful of almost useless words. No details, no answers to our questions and doubts.
No pictures. No effort at all...at least less than anyone of us.

Klaus