Babysitter construction help

[Russellc]

Thought one of these would be handy for this summer, thinking of these fans:

Amazon.com: Noctua SSO Bearing Fan Retail Cooling NF-P14s redux-1500 PWM: Computers & Accessories

or something similar. Would like advice on some type of controller, that would let sink get to certain temp and switch on-off maintaining optimum temp. I see several talking about these ideas over in Turbo F-5 thread, but no specifics. Would love to see some ideas.

This would prevent fan running on and on keeping sink below optimum temp...

Thanks for any direction,

Russellc

 

[Zen Mod]

LM317 , variable , and some time , using palm rule

either that , or arduino , home server , implementation in national security alert scheme etc.

sky is the limit

 

[Russellc]

Found a little surfing around your suggestion, found this:

Cooling fan temp controller | Make: DIY Projects, How-Tos, Electronics, Crafts and Ideas for Makers

http://www.heatsink.info/content.php?content=control.shtml (click on "temp control")

I think a couple of these, (for a two fan babysitter) mounted in babysitter, heatsensor wire going through 5U cases perforated floor pan and then in contact with heatsink ought to do it.

Your first idea would work as well, I understand you mean to have a little 317 regulated power supply and just adjust fan speed to appropriate place for a given ambient temperature? Plus, this style would be a little easier to move from amp to amp...

I wondered about something similar to thermistor sensing heat on the F-5's mosfet, except something on heat sink. The link above has a link that I am still combing through.

I may be remembering wrong, but I think it was CanAm man that built a F-5 with some kind of temp control that operated fans, I may need to check with him or whoever that was.

Thanks,

Russellc

 

[Zen Mod]

do what your heart's wish is ..... but for Mighty Moi , simple LM317 circ is all I need

 

[Russellc]

do what your heart's wish is ..... but for Mighty Moi , simple LM317 circ is all I need

I do have some 317 bits laying around from B-1 power supply build. keeping motor at lower rpm would make for most quiet.

Russellc

 

[WalterW]

Or build a real Pass fan controller, with Mosfet of course 😀

 

[Zen Mod]

yup

😉

that's smart one - with turn on kick

 

[CeeVee]

..or you can just use a dedicated IC:

http://www.datasheets.pl/integrated_circuits/T/TC/TC642.pdf

😀

 

[Russellc]

Or build a real Pass fan controller, with Mosfet of course 😀

I like this, is IRF like on my F-5 outputs too large of a mosfet? How small can it be? Obviously it must at least handle the draw of the fan...any one know what mosfet Pass labs uses for this position?

Russellc

 

[Zen Mod]

size of IRF510

dissipation is negligible

 

[CeeVee]

...You can use the mosfet with the microchip ...see link.

And you can set the max temp profile you want and let it regulate itself.....no programming needed only one R to specify.

better is difficult.

For me it makes a lot of sense....last few days have been close to 40ºC here in Lisboa and i dont want to have to tune the fan speed all the time....i use 2 , one for each heatsink
and let them maintain the max temp i specify in summer.

....although the very hot days they are not so quiet.....it's way to hot to run class A.

It's either that or use the air conditioning....or both....

😀

 

[evanc]

excuse the poor drawing...this works...controls the fan speed nicely and has good adjustment. I just wedged the thermistor into the heatsink fins. Same thermistor parts I used for bias control in my pass amps.

 

[wdecho]

What is the best and simplest way to reduce the voltage from 24V to 12V. I have researched a few ways but would like to get feedback on what members consider the best and simplest way from the amplifiers PS.

David

 

[Russellc]

size of IRF510

dissipation is negligible

Thanks!🙂

Russellc

 

[Russellc]

excuse the poor drawing...this works...controls the fan speed nicely and has good adjustment. I just wedged the thermistor into the heatsink fins. Same thermistor parts I used for bias control in my pass amps.

Very interesting, but I, being an electronics numbskull, will need a bit of instruction about what value range of resistors to use to set temps....😕

Sounds like a good idea, now if I can implement is only remaining question. I'll read the info thoroughly and see if I can fathom it...return with finishing questions.

Russellc

 

[Russellc]

What is the best and simplest way to reduce the voltage from 24V to 12V. I have researched a few ways but would like to get feedback on what members consider the best and simplest way from the amplifiers PS.

David

I was going to butcher a wall wart....But what do I know?

Russellc

 

[evanc]

I used a wall wart for power. No resistors. 10k pot for adjustment of when fan comes on and thats it. I have built a few of these and they work great.

 

[Dennis Hui]

I was going to butcher a wall wart....But what do I know?

Russellc

Yeah, something simple like a wallwart for a babysitter.

I suspect David's question might be about adding a fan internally to an amp.
Assuming the fan doesn't draw much current then wouldn't something
like an LM7812 regulator be adequate?

Thanks,
Dennis

 

[wdecho]

Yes, I am talking about using a fan inside the amplifier. I have one amplifier that has to have a fan because of inadequate heatsinking. Looking at a schematic of an Aleph 3 it appears to me that a 330 ohm 1 watt resistor is what is used to drop the voltage for the fan but I do not know the voltage is for the fan. From what I have found a single resistor or a couple of resistors used as a voltage divider or a regulator can be used. I thought I may profit from someone else's experience who has done this before about what they used and the values of the components used. A simple walmart may be the easiest without experimenting. Thanks for any input.

David

 

[AudioSan]

Russellc: If you only need a babysitter fan for the real hot days and just in case, why use fan speed control circuit? a simple temp switch mounted on the sink and connected in series with the fan will do the job. this will power on the fan at a given temp and cut the power to the fan when the temp is around 10c below the limit.