fan switch= really hot

its not that but my fuel pump the fuse line....it got cut i guess putting it back on the silonied b/c there hiddin behind the fender and i guess it was cut on the opening circle it comes to go on the silonied


yea i cant spell.....but with the fueslink that got shocked it should of saved the fuelpump and soliniod from being ruin right?
 
Michael Yount said:
id - I suppose it could be semantics, but there's no way I'd describe something which infinitely varies the CURRENT to a motor to infinitely vary the motor rpm in order to maintain a set temperature point as simply "a switch". The toggle you buy at WalMart - that's "a switch". The term switch is pretty universally accepted as a device which allows a connection to either be made, or not made. Binary. On or off. This piece couldn't be described that way, at least not reasonably. :)


...but thats just my point. The connection is "made or not made". It just happens so fast, you don't know it. PWM = Pulse Width Modulation. This is a binary event that is time proportioning. Low temp = short pulse width. Hot temp = longer pulse width. Essentially, the duty cycle of the fan drive is a function of the input RTD. The current delivery or power factor is controlled very efficiently in this manner. Hence why this product is so successful as it is efficient and eliminates mechanical switching latency (hysteresis error) and improves reliability by eliminating mechanical contacts. :D
 
this is what i like. two of my favorite guys, Michael and ID, both engineers, enjoying a friendly debate that few of the rest of us understand. :-)

but overall, it balances out. these two guys are over my head, but on the other side, i really dont understand what the heck Sidewayz is trying to explain (no offense to you, Sideways, but a little grammatical clean up, like periods and commas, could really help us to understand). :-)
 
ID - "Hence why this product is so successful as it is efficient and eliminates mechanical switching latency (hysteresis error) and improves reliability by eliminating mechanical contacts." You've just given a perfect arguement as to why it most folks would never call it a "switch". The end result of its super-fast switching is that it doesn't behave like a switch at all. Some things fall into the category of being described as a distinction without a difference (e.g. - do the cylinders 'suck' air in on the downstroke of the piston, or does atmospheric pressure 'push' air in?). This isn't one of them in my opinion. If it doesn't walk like a duck, look like a duck, or quack like a duck, then it's not a duck. This ain't a switch.
 
Michael Yount said:
ID - "Hence why this product is so successful as it is efficient and eliminates mechanical switching latency (hysteresis error) and improves reliability by eliminating mechanical contacts." You've just given a perfect arguement as to why it most folks would never call it a "switch". The end result of its super-fast switching is that it doesn't behave like a switch at all. Some things fall into the category of being described as a distinction without a difference (e.g. - do the cylinders 'suck' air in on the downstroke of the piston, or does atmospheric pressure 'push' air in?). This isn't one of them in my opinion. If it doesn't walk like a duck, look like a duck, or quack like a duck, then it's not a duck. This ain't a switch.

I agree most folks would not call it a switch. When a dam gate opens and water flows it may not be called a switch, but it (the gate) acts like a switch (on or off). The dam gate may not look like anything you've seen in the local wall mart, but it sometimes takes "vision" to see the subtle.
 
:) I've enjoyed the thought provoking discussion ID. Probably a case of you say tomato and I say tomahto more than anything else. Living here in east TN, we're covered up with dams (Tennessee Valley Authority and Alcoa) - most of those gates I've seen are adjustable. Tiny opening, bigger opening, open all the way - definitely not all or nothing like a switch. Additionally, I've always thought that the term vision was more appropriately used to describe the ability to take in all the details, and summarize them on a grander scale. Perhaps it takes the ability to 'visualize' the detailed operation of the unit to see it as a switch. Oh no, here we go again.... LOL :)

You're right - it's a switch that's cleverly disguised so it doesn't act like a switch. I can live with that.
 
Michael Yount said:
:) I've enjoyed the thought provoking discussion ID. Probably a case of you say tomato and I say tomahto more than anything else. Living here in east TN, we're covered up with dams (Tennessee Valley Authority and Alcoa) - most of those gates I've seen are adjustable. Tiny opening, bigger opening, open all the way - definitely not all or nothing like a switch. Additionally, I've always thought that the term vision was more appropriately used to describe the ability to take in all the details, and summarize them on a grander scale. Perhaps it takes the ability to 'visualize' the detailed operation of the unit to see it as a switch. Oh no, here we go again.... LOL :)

You're right - it's a switch that's cleverly disguised so it doesn't act like a switch. I can live with that.


Its true, the dam gate can operate in an on-off or anywhere in between mode. In effect the rate of opening may determin if the output is more analog or more binary. (digital designers face this problem in silicon as-well) However, imagine the dam gate opening very quickly and the amount of time it ramains open is varied. This represents the duty cycle (% on vs. % off). The fan controller can work in the exact same manner. The resulting power delivered to the fan may appear to behave in a more analog mode (speeding up or slowing down as the temperature dictates). But, the driving force is a digital PWM electromotive force.
In this case it really doesn't matter if its a tomatoe, tomAto or carrot. The end result is a product that many people seem to like.
 
waoh.........ha no clue got a lil too lost, but i did put the new fuselink on the fuel pump that goes to the battery silenoid(sp?) so far so good. I made a connection by the relay where i can bypass the switch or not. So ill leave it there till i get a different switch. thanks for all the help


oh yea the relay wasn't blown, Im thinking that when the fueslink went since it was before the fan power wire it was blocking it but it works fine now.
 
Idwitheld-1` said:
not to split hairs but it is a switch. Its just solid-state (probably PWM modulation with FET or bipolar drivers).

The diagram leads me to believe it might be an Op Amp where output voltage varies in proportion to the input (temp sensor).
 
FROM DC CONTROL WEB SITE:
"The DC series high efficiency pulse width modulators
comprise a high side DC to DC voltage converter,
over/under voltage, over current, over temperature, and short
circuit protection circuitry."

The module probably uses op-amps for signal conditioning and increased S/N ratios but ultimately it gets converted into a pwm signal and probably ends in some very large discrete driver(s).
 
Michael Yount said:
The toggle you buy at WalMart - that's "a switch". The term switch is pretty universally accepted as a device which allows a connection to either be made, or not made. Binary. On or off. :)


:OT:

Just to add a little fun to this. I define a switch as a moderate to large computer system that routes phone calls or data.
A large PBX is a switch. The 30 million dollar Lucent Technologies wireless 5ESS that I maintain is accurately called a switch. I have a few cisco data switches in my office as well. It is somewhat unlike you to have such a narrow definition of a term. Id rather have a few Lucent switches to sell on ebay than the ones a walmart.

FYI: As far as motor starup current draw, for generator sizing you calculate 7 times the normal duty curent as the initial current draw. So for a 30 amp motor, expect it to draw 210 amps for the first smallest instance that power is applied. The obvious lesson here is that the motor will draw the most current when stalled and will draw less and less current until it approaches its proper rating and RPM/LOAD design. Dont know how that would apply to relays, but it should be the same theory. To properly engineer a relay, you should assume at least 150% duty. In otherwords, for a 20 amp load, you should chose a relay capable of 30 amps.
 
Here is a simple and cheap way to fix the overcurrent problem (if one exists). Use to relays in parrallel. That would give 60 amps current capacity for the fan.

I run 2 10 inch fans and use 1 30 amp lighting relay. I have no overcurrent issues or heat of anykind. I use a painless wiring switch/fuse panel to power the relays and it has lighted switches.
 
the most effective switch i have seen lately: going from Metamucil to Ensure. my oh my. and that switch segues into plumbing.......

sorry, i have only a semblance of an idea what you all are talkin about, so i am here to provide levity (or attempt to). :D
 
hllon4 - that's good! I love the bit about switches and BIG switches....kind of like y'all (singular) and all y'all (plural). As for narrow definitions, context is everything baby....the railroad engineers have a different way of describing a switch too. But we're not talking dams, trains or phones here - just fan control on the car. We could all go on, but let's stop, shall we? :)