GPz1100

My setup is as below.

1) These are huge images (some nearly 1.5 MB in size), dialup users beware.

2) If you link directly, they will be removed. Please link to this thread.

http://home.comcast.net/~zx1100e5/pics/100_1140.JPG amp rack 1
http://home.comcast.net/~zx1100e5/pics/100_1141.JPG amp rack 2
http://home.comcast.net/~zx1100e5/pics/100_1142.JPG amp rack 3
http://home.comcast.net/~zx1100e5/pics/100_1143.JPG amp rack 4

Previous pics http://home.comcast.net/~zx1100e5/pics/

The smaller amp is an alpine 3552.

After running a while, it gets hot.. really hot. Not enough to trip its thermal protection (I assume being a top of the line amp from 1992? it has this), but awfully hot to the touch.

I'm tossing the idea of hooking up some 120mm pc fans. Noise isn't much of an issue since its all the way in the back, and I'll never hear them over road noise anyways.

I know the remote on goes to +12 when the HU is active. But also, I believe the remote on is limited to 200-300 mA max. I was thinking of devising a small circuit using a darlington driver to power the fans directly. The IC I have in mind is a 6 or 7 channel, 500mA max/channel capable device.

Any other suggestions?

redline2k

iTrader: (9)

all you need is an automotive relay

Your turn on wire goes to pin 85
ground pin 86
+12 volts to pin 87
output to fans and amps goes to pin 30
leave 87a empty

GPz1100

These standard 30A relays, what are the coil ratings? The spec from the HU is not to exceed 300mA on the remote turn on.

I wonder what the typical amp draws to be triggered on.

Trent

iTrader: (3)

Amps are supposed to get hot. They are designed to work and operate well when they heat up like that. I run two kicker 850 watt amps in my car at 3/4 gain and they get VERY hot to the touch. If they don't kick into thermal protection, then let them do what they are designed to do.

GPz1100

Trent,

I don't entirely agree with you. Heat is a byproduct of the amplification process. Obviously the amp is quite inefficient if much power is wasted as heat. Given this amp is ~15 yrs old and uses older technology that would make sense (about being inefficient).

However, heat and solid state is not preferred. The hotter something gets, the more likely for component failure.

In addition, consider thermal wear - each time the device goes through a thermal cycle, it expands and contracts [at cool down]. Eventually the device fails because of microscopic cracks developed.

redline2k

iTrader: (9)

It is 30 amps for the output it takes less than 150mA to trigger the coil. I do this for a living it will work perfectly for you.

methane

iTrader: (1)

physics lesson....electrical energy is either converted to sound or heat.. which would you prefer?

how many ohms is that amp running at?

GPz1100

Redline2k: I was under the impression those bosch style relays took more mA to energize. I also do this for a living, but haven't had too much exposure to these recently.

methane: In an ideal world, 100% of the energy would go towards the sound

The 3552 uses BJT's for its output stage, not mosfets like current amps. Running in bridged mode (85 x 2) driving a pair of 4 ohm speakers (1 speaker for each channel).

The amp was in service until ~2001 when I sold the last car it was in.. Been sitting on a shelf since. Still works well today, and would like to get more years out of it.

redline2k

iTrader: (9)

The coil rating on the relay is 160mA at 400Ohms

Just in case you still have a doubt

I am an MECP certified installer and I have been doing it for 16 years. A bosch style relay is the best way to do what you want to do. Also if the amp is that old it may not have any thermal protection. Old Rockford Amps had no thermal protection until one of them actually caught a guys car on fire and they got sued.

GPz1100

Something doesn't add up [unless I'm overlooking something]

Assuming 12V operation, if it draws 160 mA, then the coil resistance should be ~ 75 ohms (R=V/I). If the coil is indeed rated at 400 ohms, then the current should be ~30 mA.

But, in either case, agreed, it should work without overtaxing the sourcing ability of the remote turn on from the HU.

Re thermal protection, according to the alpine tech I spoke with yesterday, it does indeed have this function.

Phoenix 5.7

iTrader: (7)

or 64v. if you wnated fans then you could have some that are temp activated. http://www.heatsink-guide.com/conten...=control.shtml here is a way to make a temp controlled 12v fan

CAMAROWITHBASS

iTrader: (2)

get crossflow fans, their much better.