reg/rect Cooling

[lecroy]

"I'm just trying to help people on this website. You?"

I'm just trying to help you.


So, for example if you have a block of aluminum, say 2 x 2 x 2. Will this block cool the same as one that has cuts make into it to create the fins? If the fins are mounted vertical in air it will. If it is mounted horizontal it won't. If it's in a perfect vacuum it's the same. In no air flow the virgin block will provide the best heat dump.


"Do engines get hotter than electronics? In general, yes. OK pedant go and find me an example of something to prove me wrong, but you know where I'm coming from."

Yea, but I'm a detail kind of guy.

"You know full well that I'm not talking about expense for the sake of it or rarity value."

Sorry, but I didn't. That's why I asked you to clarify what you were saying.

I'm talking about a designer trying to meet a budget and choosing the cheaper option in the design and/or the specification of discrete components.

Yes I agree. I can design crap for the same amount of money as I design something good. But more often that not, not the other way around. Automotive electronics, at least here, is a tough business. Everything is cut to the penny. If you want to make your design more robust and it added money but was not part of the original spec. you won't get the business. Keep in mind also that warrenty can play a big part in a companies business. Where would the auto parts store go without failed parts? I guess they can continue to sell those fuzzy dice.

"I'm also talking about 25 years ago in Japan. "

Does not ring a bell with me.

"There are many examples of this I could give you both from my experience with bikes and in my work, but I can't be bothered."

Too bad. I would like to hear them. I just have not seen any big trends. If anything, I would have to humble myself and say they really did a lot to help the electronic industry in every way. Even the advances in no lead solder seem to come from Japan.

"You're making me tired here. "

Go take a nap!

 

[Anonymous]

We're not comparing a 2x2x2 block versus the same block cut for fins. In reality you would make the thing bigger by adding fins.

Also in reality there is rarely "zero" airflow. A reg/rec under a battery box is going to get a fair amount of air movement around it at most speeds above stationary. As you said, following Granny.

An example from my work is that recently we started to see failures on a particular PCB. The failure analysis found that the part vendor had changed component suppliers for some of the components on the board in an effort to maintain profitability in the face of the continued slump in the semiconductor industry, which has focussed attention on costs. They had found a supplier who could supply an identical (nominal)spec part at a much lower cost. Returning to the original supplier cured the problem.
This is not an isolated occurence, but is happening all the time, both on current lines and on the introduction of revised items which turn out to be less reliable than the old item due to the constant downward pressure on costs. Cheapest components, cheapest design and cheapest production methods.

My point is this: Its possible to put a good quality well designed RR in the same (less than ideal?) location and it be less likely to fail than the original which may have been compromised by production needs. Proof? My Gs's now have better charging systems than they did when they left Hamamatsu. More proof? Many bikes produced in Japan at the same time had charging systems which have been 100% reliable to this day.

Look lets quit all this academic debate. My fundamental points are correct as are all the points you are making. You are over analysing my statements.This doesn't contribute anything to the discussion, which is reg/rec cooling.

You are patently a qualified and knowlegeable person, so I would like to ask you this: Is it necessary to improve the cooling to a regulator and rectifier on a typical early GS?

Also: If so, is this still the case once the charging system has been modded by the fitment of an aftermarket reg/rec such as an Electrex?

My opinion?
In the case of the first question, don't know, I've never had a GS where the original reg and rec have lasted long enough.
In the case of the second question, I would say no as I have never had a problem with the replacement Electrex's I've fitted. My belief is that these RR's are robust enough to tolerate less then perfect cooling.

 

[redliner1973]

OK guys, here is a simple one......Underneath the airbox is the opening or the intake. In a four cyl engine, there is alot of air in that box.....whilst the engine is running, the seat, sidecovers, and airbox form a kind of 'chamber'. in this 'chamber' if you will, air is being drawn in from all the little 'nooks and crannies' in this area and going onto the airbox inlet. whislt this air is around, and moving through this area, it cools the regulator. hence the reason it is in the location it is. lots of airflow, and protected from the elements at the same time.......!

 

[lecroy]

"An example from my work is that recently we started to see failures on a particular PCB. The failure analysis found that the part vendor had changed component suppliers for some of the components on the board in an effort to maintain profitability in the face of the continued slump in the semiconductor industry, which has focussed attention on costs. They had found a supplier who could supply an identical (nominal)spec part at a much lower cost. "

Again, I would need much more detail. But the root problem may not have been that the part was changed but rather that the part you are talking about was not designed for worst case conditions. All devices will have tolerences on them. If the designer does not take all of them into account in his design you run into problems.


I though you could follow the 2x2x2 block and the idea of effective surface area. Just the basic idea that for the same outside dimension that you can lower the resistance by adding surface area. Motorola had a good book on the subject that you can get for free. Maybe it would help.


"Also in reality there is rarely "zero" airflow. A reg/rec under a battery box is going to get a fair amount of air movement around it at most speeds above stationary."

I believe this was my original point.


"Is it necessary to improve the cooling to a regulator and rectifier on a typical early GS? "

In my experience this is not the case. I have yet to see a heat related failure on any of my bikes over the past 30 years. I have purchased one of my 83s in 84 and the other around 87. Both have all stock electrical parts. The problem is that I tend to ride Suzuki and have owned a very limited number of bikes. Maybe 20 or so. So the sample just is not high enough to make any kind of a confidence call. I went to the Electrex website, but they do not seem to supply any data on required air flow, max. ambient temp. or mounting that I could find. There was also nothing on max. operating current, voltage. Worse, nothing on the regulation. I guess they could sell you anything and it would be within their spec.

 

[Anonymous]

reg/ rec

reg/ rec

I put my reg/rec up front where the horns were had to make bracket ran wire under gas tank and spliced in 6 inches of wire so it would reach stator gets lots of AIR TO STAY COOL you can touch it and its warm not hot like it was before when it was under battery hope this will help you all out took me 2hours to move it. 1982 GS1100GKz

 

[Anonymous]

"I'm just trying to help people on this website. You?"

I'm just trying to help you.


So, for example if you have a block of aluminum, say 2 x 2 x 2. Will this block cool the same as one that has cuts make into it to create the fins? If the fins are mounted vertical in air it will. If it is mounted horizontal it won't. If it's in a perfect vacuum it's the same. In no air flow the virgin block will provide the best heat dump.


"Do engines get hotter than electronics? In general, yes. OK pedant go and find me an example of something to prove me wrong, but you know where I'm coming from."

Yea, but I'm a detail kind of guy.

"You know full well that I'm not talking about expense for the sake of it or rarity value."

Sorry, but I didn't. That's why I asked you to clarify what you were saying.

I'm talking about a designer trying to meet a budget and choosing the cheaper option in the design and/or the specification of discrete components.

Yes I agree. I can design crap for the same amount of money as I design something good. But more often that not, not the other way around. Automotive electronics, at least here, is a tough business. Everything is cut to the penny. If you want to make your design more robust and it added money but was not part of the original spec. you won't get the business. Keep in mind also that warrenty can play a big part in a companies business. Where would the auto parts store go without failed parts? I guess they can continue to sell those fuzzy dice.

"I'm also talking about 25 years ago in Japan. "

Does not ring a bell with me.

"There are many examples of this I could give you both from my experience with bikes and in my work, but I can't be bothered."

Too bad. I would like to hear them. I just have not seen any big trends. If anything, I would have to humble myself and say they really did a lot to help the electronic industry in every way. Even the advances in no lead solder seem to come from Japan.

"You're making me tired here. "

Go take a nap!

Sorry, had to jump in here.
"So, for example if you have a block of aluminum, say 2 x 2 x 2. Will this block cool the same as one that has cuts make into it to create the fins? If the fins are mounted vertical in air it will. If it is mounted horizontal it won't. If it's in a perfect vacuum it's the same. In no air flow the virgin block will provide the best heat dump."
Actually, in a vacuum, the finned block will still radiate more heat at a faster rate. There does not have to be air to radiate heat, thus the term "RADIATE" derived from radiation.

 

[lecroy]

"Sorry, had to jump in here. "

Hey, that's the idea. Why say your sorry?

"Actually, in a vacuum, the finned block will still radiate more heat at a faster rate. There does not have to be air to radiate heat, thus the term "RADIATE" derived from radiation."

Yep, you have me on that one. I have done some testing on electronic parts in a deep vacuum (2 x 10-7) and find that you really need conduction into the outside world to get any cooling. Of course I wasn't making my parts glow. Radiation provides little cooling. Convection also provides some cooling but there is not much stuff left in a vacuum this low. I was blabing about the convection kind of cooling in this case. The kind that matters on your bike. Somewhere on my dickey site there is a bunch of info on designing electronics for space flight. Fun stuff if your a G'ee'k.