mgntwo

Hey guys im trying to add a cooling fan to keep my amps cool. Im trying to find the best way to wire it in. My first guess is tap into the turn on lead. Is this the best way? Thanks for the advice guys.

redlude97

iTrader: (11)

tap into the turn on lead to power a relay to run the fans off. Also make sure a diode is used so the backsurge when the relay turns off doesn't cause a popping sound from the subs

tattoo60012

What redlude97 said is absolutely correct, if you try to go straight off the RTO lead you are forcing your head unit to power your cooling fan, and besides the excessive current draw from the fan motor, you can also introduce motor noise into the circuit which can and probly will backfeed to the head unit causing more problems for you than just hot amps.

16psibrick

iTrader: (10)

well this depends honestly, if its a very simple CPU type of fan, chances are it doesnt draw nearly enough current to do anyhting to the RTO signal, if you are just using one or two, and only turing on one amp or so...

but, if you are using a crossflow, or mutiple fans or have multiple accessories to turn on, es absoltuely, a relay is the way to go.

i pretty use relays on everything, but just asying, from experience, doing one or two small CPU fans of a lightly loaded RTO wire is fine...

tattoo60012

Oh absolutely, I couldn't agree more, I just assumed (there's that word again) that if he NEEDED a fan to take care of heat issues, that the fan would be significant enough to warrant a seperate circuit.

mgntwo

Im using a stinger pf2 fan, the larger of the two. the draw they say .3 amp. I have kenwood mp7028 head unit. What type of relay and diode should i use. There is also the idea of using the power antena lead from the head unit cuz that is also a hot wire.

i8acobra

iTrader: (6)

Here's a little diagram I whipped together:

Paul350Z

iTrader: (1)

I run a tiny 20 cubic feet per minute fan that directs just a puff of air between my amplifiers. Helps just a ton over natural convection. I was playing with an IR camera and should have thought to bust open the amplifier cubby and take some measurements - next time possibly.



My amplifier turn-on circuit is good for 0.5 amps. My amplifiers draw 0.1 amps meaning I have 0.4 (400 milliamps) left over for the little fan. I've heard no noise caused by the DC fan. I did the thermal load on my ~1200 worth of amplifiers with no fan in the subwoofer cubby and there wasn't going to be a problem. Being a belt and suspenders kind of guy - and living in SoCal's desert where the day time temperatures can hit 115 degrees - I thought the little fan would help.

There's a formula to calculate the heat produced in BTU and the insulation properties of various metals and materials. A fan helps strip the air from the heat sinks increasing their abilities to remove heat. The fan faces forward blowing air between the amps and toward's the empty hole where the subwoofers used to be. There is just the most gentle sound coming from the hole with the sound down and a soft breeze of warm air.

Diodes are placed reversed biased across heavy duty relays to reduce sparking between the armature leg as it closes. I've never known one to be use with any light duty relays - say less than a few hundred watts worth of load. It might be an audio tuners thing that I've never heard of though.

16psibrick

iTrader: (10)

paul, having met you, why am I NOT suprised you have a IR camera haha

b

KPierson

iTrader: (1)

I want an IR camera!!!!

Thermography is cool!

Paul350Z

iTrader: (1)

Thermography is hot!



(engine compartment - the bright spot is the radiator hose)

Paul350Z

iTrader: (1)

It's my uncles