LinkBack URL
About LinkBacks
Reply With QuoteAC components = the waves on top of the DC voltage, noise, hums whatever mixed on a DC.
What I meant was to smooth any dirty bits on the DC and keep it 100% DC.
Ok no more confusion
Originally Posted by Ricky327
Ok...maybe I misunderstood what tank really meant :
So that tank circuit was just there to smooth out the "AC" components of the supply during cranking. Just as found in a power supply circuit where you have a smoothing capacitors...it will not keep the 12V during cranking.
If smoothing was all needed then that diode shouldnt be there at all as the voltage never goes negative.
I thought the whole idea was to survive a crank due to heavy load from the starter motor?
Correct me if Im missing something here
Yes that is what it is supposed to do, but it doesn't need to supply the full 12v - the starter doesn't take ALL the juice. Smoothing is all that is needed with a good dc-dc PSU.
Not sure what you mean by "AC" - I'm talking about dc-dc PSUs here.
AC components = the waves on top of the DC voltage, noise, hums whatever mixed on a DC.
What I meant was to smooth any dirty bits on the DC and keep it 100% DC.
Ok no more confusion
i'm still waiting on the proof ... i've had enough of people saying "yeah man it works" ... do it ... and if it works post the details so we can close the books on this one.
My JeepPC Install
"there are no stupid questions, just stupid people."
"it's been agreed the whole world stinks so no one's taking showers anymore"
Well...
From what I was told this 1F tank doesnt work unless you have a good PSU. All it does is smooth out the "roughness" during cranking.
So all in all its not designed to survive a crank...its main purpose is just to smooth.
Dont ask me why someone call it a tank circuit which alot of people here still believe its there to survive a crank. As I did say the diode is NOT needed if smoothing is all that required.
Getting clearer?
I'll echo what the other guys above said, a second sealed lead acid battery is probably easier to use (with an isolator), and definately safer!!
1F caps are extremely dangerous, you wouldn't want to be in an accident where one of those was squashed >_< 1F of charge is a huge amount of energy, and it'll probably drain your car battery charging the thing.. actually i still have no idea why 1F caps are even legal in most countries as it'd be pretty easy to build a bomb out of one....
OK keep asking for proof and then shout down those who offer it. Good plan.
I know it won't work for a POS PW60/70/120 whatever. I said so. You need to give up on that crap and get a decent PSU.
As I said before, come to my house and see my Sproggy 2.8+ survive cranks. A major difference between this revision and earlier ones (that didn't so easily survive cranks) are the bigger caps on the input. Do your math on that.
I agree that a 1F cap is ridiculous. Nothing even near that big is needed.
boy you just can't let things go can you? i thought we already solved this in another thread?? that was posted before you ever told me you had "proof"
as i said before, my statement has always been that capacitors alone cannot successfully be used as a tank circuit on their own. That cannot be refuted as caps discharge way too quickly to provide the power needed to last a crank.
In your setup ... and from what i've heard from others with opus ... you're able to survive a crank. but it's not only because of the caps! it's because of the opus/sproggy.
if I'm understanding you correctly ... you ahve a few caps (i think you said 2200uf) sitting in front of your sproggy circuit yes? if you remove those caps are you still able to survive a crank?
post a schematic of your setup if you can.
by all means add your input to this board but stop giving me crap about a point i'm not making. all ricky and I are saying is that capacitors alone cannot provide enough juice to provide 2-4v @ approx 5a (to compensate for the starter's draw on the battery) through a crank ... will you argue against that???
My JeepPC Install
"there are no stupid questions, just stupid people."
"it's been agreed the whole world stinks so no one's taking showers anymore"
I've never disagreed with that - only with any notion that such drastic measures are necessary. You've just ****ed me off by shouting NO too often without even reading the relevant posts (as you've admitted.) Your statements have not always been so constrained as this one, they are far more often blanket dismissals and talk of "putting all talk of cap tank circuits to bed." Those are the comments I mean to respond to, sorry for having a job and having to hurry my aim.
all ricky and I are saying is that capacitors alone cannot provide enough juice to provide 2-4v @ approx 5a (to compensate for the starter's draw on the battery) through a crank ... will you argue against that???
I agree
The original circuit design was supposed to survive the crank even if the PSU is badly designed or not. Im sure that was the main intention was.
None,
If you look at sproggys design the +12V supply is derived from the +5V by means of a step up regulator. In theory even if the starter motor drain as much as 6V or so the circuit should survive a crank because the +5V is never effected and therefore the +12V wont get effected either.
I dont know the exact operating voltage of the sproggy but you can see it will survive the crank with or without the tank circuit.
Using the 1F tank circuit on any power supply simply wont do anything at all.
As EPIA motherboards don't use the 12v rail, a crash here won't cause a "tank." It is all about the 5v, and thus, amperage available. As such it is all about efficiency of that 5v regulator, not about minimum voltage.
Posting Permissions
Bookmarks