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Thread: New here! hello and a bit of a plan!

  1. #11
    Raw Wave
    Join Date
    Nov 2009
    GiorgaKiSs - you are a pleasure! (That means I like you.)

    Apologies for my expression - and please continue to ask. Whilst American movie stars think foreigners understand English if they just speak s-l-o-w-l-y. I'm Australian and now that nobody understands us (eh mate?) even though I live in the second biggest Greek city in the world (or was).
    (And I won't post any smart Greek words. Last time I tried that in Swedish I got gay confused with horny. (Isn't gay related to the Mallacan Straits?)

    By that ground's "accidental inclusion" I merely meant that diagrammatically, it shows the red +12V connected to black 0V (ground).
    But I assumed that was a error, else meant pehaps you were using shielded cable etc.

    But you are correct - the screen must be grounded and from its power supply .

    If it was not grounded, it would find some other grounding path and probably blow its components. That's bad for most input and output circuits.
    (Though by lucky coincidence, VGA and similar interfaces often use a shielded cable. The outer shield connects each end's VGA-connector's ground together (and these are often chassis ground) and thus can ground the screen. (The shield being relatively heavy and carry more current than other signals.) Other cables can do the same - eg Ethernet etc Cat-5 cables if all "returns" for each signal wire are connected together and to ground.)
    BTW - this relates to the separate termination of signal grounds and power grounds even though somewhere they will be connected together (but only from one interconnection) - by that's another story!

    By commoned together, I simply mean connected together.
    EG - your amp supplies should be common = connected together - ie, using that power distributor. It seems "we" also think the PSU (Power Supply Unit - ie (1) Car PC Pwr Supply) should be separate to the amps - or don't need the cap(acitor). Hence common = connect the PSU's power input to the screen's power input - as if they had their own Distribution Block (power distributor).

    That makes sense from a general electrical and system distribution POV (Point Of View).
    IE - the audio system is it's own distribution system and separate from the PC's components and system.
    Each would probably have their own (separate) fuse(s) so that if the audio overloads, it merely blows its fuse, but not the PC's fuse.
    (Wouldn't you hate it if a fault in the smaller or less important amplifier blew the fuse that also protected the PC? The PC dies just as Greece kicks the winning goal against the Turks!! Or better still - the Swedes! Yay!)

    So....what for the "? fuse" 1A or 5~10 A ????
    Aha! Basic fusing (aka protection) theory! (aka = also known as; aka "(is) also called")

    1 - Equipment Protection - each piece of equipment should have its own protection - ie "blow its own fuse" - rather than destroy itself.
    Most overload sensitive or fault-prone devices have their own protection. EG - amplifiers, televisions, house electrics. Their fuses may be user-changeable and easy to get to (amps, house) but may be internal when they are not expected to blow, but are still the sacrificial component that is sacrificed to the Great Smoke God (eg, multimeters aka DMMs, televisions, radios).

    If an equipment does not have its own fuse, then it may be grouped with others. This is seen in car electrics - many circuits might share the same fuse. The fuse is big enough to handle all the different loads (circuits), but small enough so that if a fault on any circuit - like a short to ground - will blow the fuse. (Note that when shared like this, circuits are usually "grouped" into related functional groups. Or sometimes deliberately separated - eg left headlights from right, or hi-beam form low-beam - so that if one blows, you still have something available or some alternative.)

    If equipment does NOT have its own protection, you may have to provide it.

    2 - Distribution Protection - the protection of the power sources, cables and wires.
    If you short a car battery, you will have massive sparks, heat, and maybe an explosion. Hence you must have protection that avoids that.
    In old days, the protection was the "physical security" of the distribution (wires) from the battery to the fuses (often in the cabin).
    These days, there are usually main or master fuses - often call fuselinks - at or near the battery to provide electrical protection (aka security) from battery shorts etc.

    But those fuselinks (aka flinks) are also sized to protect the "downstream" wires that go to the amps or Distribution Blocks or fuse blocks etc.
    EG - a 1000W RMS amplifier may have a 150A cable supplying it from the battery, so there might be a 150A (or smaller) flink or fuse or circuit-breaker at the start of the 150A cable.
    That 150A cable might be supplying your amps instead. The 150A fuse is NOT to protect your amps, but the distribution to them - your amps have their own protection as per (1) above. [If your amps are only 40A, you might use a 40A or 50A or 60A etc for the 150A cable. The 150A cable is still good because it means less resistance than a 40A cable, but you may niot need and expensive 150A fuse. Using a 40A fuse "upstream" may save using a 40A downstream fuse at the amp end.]

    Power distribution is often a "fan-out" situation - eg, an 80A main circuit splits into 2x40A circuits and one of those 40A branches into 3x10A & 20A & 5A etc.
    Each sized cable should be protected upstream. IE - the 5A circuit with 5A cable has its 5A fuse which is powered from the 40A cable & its fuse fro the 80A cable and fuse.

    Power distribution can be tricky because you want the downstream fuses (eg 5A) to blow before the upstream fuses (40A & 80A). (This may seem ridiculous, but because fuses have different response characteristics - it can happen. It's probably a more common problems with (mismatched) circuit breakers.)
    The upstream fuse may be smaller than the total of the downstreams because provided it protects its immediate cable, it may be setting some maximum current for all the downstream loads (ie, no individual fault, but the lot is taking too much power/current).
    Likewise the upstream fuse may be larger than the downstreams because it is merely protecting its own wire.
    And as per the amp example earlier, of the largest or only downstream fuse is 5A, then the upstream 80A fuse could be replaced by a 5A fuse and the downstream 5A fuse omitted. This is common in "minimal resistance" distributions such as audio systems whereby you remove one fuse (resistance) from the chain. (Not that you would do that for a 5A circuit, but I'm merely explaining the principal.)

    In Summary:
    Now all the above crap is simply summarised as "each fuse protects its downstream load" where load includes wire/cables and shorts, downstream means "until the next fuse", and fuse means protection - circuit breakers, flinks fuses etc.

    But I wanted to detail different scenarios because (1) I have a rambling reputation, (2) I like to see people relax and catch up on well earned sleep, (3) I see some weird info around the place and want to overcome that, and teach people etc (else generate discussion etc).

    Another aspect is protection ratings - a general ROT (Rule Of Thumb) is that protection should normally be operating on average at not more than 70% of its rating.
    IE - a 10A fuse for a 7A average load (that can peak at 9A, and probably 12A for a few minutes depending on the fuse characteristic); but a 9A average load should be using a 15A fuse, not 10A.
    But some circuits can be more critical than that, but the they probably would not use fuses.
    Keep in mind that a fuse won't blow at a 101% overload, and it may take an hour at 110%, 30 minutes at 120% and 5 secs at 150% overload etc.
    Then there are (normal) fast blow fuses, slo-blo fuses (for motors and hi in-rush currents), etc.

    So, in answer to So....what for the "? fuse" 1A or 5~10 A ????, if the screen has its own fuse (and I expect it would - and hopefully externally accessible unless it is unlikely to blow), then you only protect the wire to it (maybe 5A etc?).
    If no fuse - or if an internal fuse - you may want to use a 1A fuse assuming that's the max current for the screen (or that 0.7A is).
    Its 9W rating is probably at 13.8V. That means 0.65A (P-VI, hence I=P/V = 9W/13,8V = .65A)
    If a "constant power" load and it can run on 9V, then it 9W = 9W/9V - 1A.
    But is that 9W rating its average or maximum consumption? Does it not have any in-rush current?
    Hence why it's nice to be able to easily change fuses - at least until stiff like hat gets sorted out.

    FYI - that M4 PSU mentioned operating down to 6V input.
    Assume it is 250W input at 6V (probably providing 225W if it is 90% efficient), that is 250W/6V = 42Amps (say a 40A fuse) as opposed to 250/12 & 250/14 - 21A & 17A (a 25A fuse) at 12V and 14V respectively. (12V being maybe typical supply voltage, engine off, & 14V engine on.)
    So the PSU (for 225W output assuming 90% efficiency = 250W input) - a 25A fuse, or 40A fuse?
    Answer??? The PSU should have its own protection, hence wire & it fuse or for worst case - lets make it 50A.
    But it is likely 25A or 30A is enough since 6V means a real bad battery under heavy cranking, and normally cranking wouldn't be for long and rarely below 10 volts, maybe 8V. And since fuses handle overloads for short periods....
    And if you use a circuit breaker for the PSU and PC - I'd advise a manual reset. You don't want an off-on-off-on-off situation for a PC!

    Welcome to the fun and simple world of system power wiring. (Where planning saves much $moke & dollar$, and you find out that a wire and a load is merely thing that contains smoke which is dying to be sacrificed and released to the Great Smoke God that resides in our wallets and heaven.)

    I'll let others suggest wiring to battery though I reckon yes - the battery is the "cleanest" power source (a battery is a big cap that filters most noise).
    But there are also circuits that connect power the PSU after charging begins (that latch on, and have manual initiation/bypass too) or you may want a second battery as is often used for hi-power audio, or independence from the main battery (in case the PC etc flattens the battery).
    And there are low-voltage cutout switches (for ~$20) that can control relays....

    But plan (which as SoundMan said - you did very well! Nice to see!), iterate (ie, change and improve), review, re-iterate, review, lose temper, argue.... get concensus/approval or make a decision ('cos we'll be - or rather, I'll be bickering forever) and get the ultimate design.
    Then you can make the ultimate sacrifice to Smokey! (aka "All care & no responsibility" aka "we don't care and it's your responsibility anyhow").


  2. #12
    Newbie GiorgaKiSs's Avatar
    Join Date
    Feb 2010
    Greece, Thessaloniki
    Quote Originally Posted by justchat_1 View Post
    One little detail that I think slipped by.....If you want to use the touch part of the touch screen you will need that usb wire connected too (not just the vga).
    I know that, u did well to remind it to me
    If i connect it it will work as a mouse, right ? So, the use of mouse will be useless..... correct ?

  3. #13
    Newbie GiorgaKiSs's Avatar
    Join Date
    Feb 2010
    Greece, Thessaloniki
    10 guys are unbelievable! No words to describe! Just second day here and you help me just like i'm your brother or something! Never seen that before! Thanks again again and again!

    Anyway......enough with ... :P .... hehehe

    Thanks for enriching my encyclopaedic knowledge, and i really mean that. From your advice i think i made correct connections! If no, please advise me!
    Any suggestions with fuses are welcome! Hehe, with your friend Smokey!

    Of course I'm not seeking for perfect.......besides if you see my car .... from the outside it looks like an ooooooolllld MK2 jetta plus it has 3 colours on it (different bonnet, doors, and rest of body). Because here in Greece thnigs are a little rough with the police, i keep it that old rusty look from the outside....but if you see inside (mechanical, and interior) you ll see everything is perfect! Plus a ..... well hidden 2L engine with the car still being 1.3L at it's license (that means that i pay taxes etc still for a 1300 cc car ). Or another example, you ll notce that i run it in coilovers..... Anyway......back to plan!

    So, capacitor is out, and a bigger battery is in it's place. Plus the 7" monitor is powered together with the car-pc power supply and the switch is now correctly connected........(I think so..)

    Let's have a look at the new plan!

    Still suggestions/corrections are welcome!


    VER. 1.1

    Thank u for your help!

    Thanks mate for your help!

    I googled before i make my plan and i found a bunch of guides for installing Windows XP to a USB Flash and make them running normally as they should and sometimes (with specific models only) running even fasted than HDDs! Not SSDs of course!

    We are still on planning so maybe till the end i'll put a real HDD! hehe!

    Greetz to you all guys!

  4. #14
    MySQL Error soundman98's Avatar
    Join Date
    Jan 2008
    on the border of northern IL/IN
    the use of a mouse witha touchscreen is only a extra way of control-- like having 2 steering wheels... for some, it might be nice, but for others, it will be useless..

  5. #15
    Raw Wave
    Join Date
    Nov 2009
    Hey GK - were are all bros, and sisters. If your are not, the POQ (Pss Off Quietly/Quickly).
    Well, let's say we should all be one big happy family. Until the misunderstanding(s). The fights...

    Not that I have time to chat... (And the crowd roared! Yay!)

    But the Corrected Plan (Rev 0.1?, or Rev1 = Ver 1.1) looks good. Certainly a much better power distribution.
    Although still using the same Pwr Distributor, it clearly splits audio from PC etc.

    If you already have the cap, I reckon you may as well use it provided it fits in okay.
    And in principle, I'd be tempted to use is for the PC & screen since the PC supply is more important - ie, a sag can lock up the PC; but only "dip" the amp.
    BUT!!! Excluding path (cable) resistances, a cap across the PC is a cap across the amps (and vice versa).
    AND - the PSU works down to 6V or whatever, plus it probably has some internal storage as may the PC itself (even if only for under a second) - so wouldn't this cater for even the worst power sag?
    (Hence use the cap for the audio for "traditional" audio reasons - which most of us realise is crap unless you cant mount a smaller battery closer etc.)
    Or the cap across the bussbar - ie, if the Pwr Dist'or has a 2nd "IN" input (next to or the same as the "IN"), you could connect the cap that IN#2 and ground.
    But it is only of use if it & the loads have a reasonable voltage drop compared to the battery, or the battery has a high(er) ESR, etc.
    Like I said - because or if you already have it, and then if it is easy to fit.

    And what's this crap about not seeking perfection BECAUSE your car is..... whatever...??!
    You remind me of a fellow (car) club member that once laughed because my $500 car had a $1,000 sound system! But that member has since shown himself to be much of fool anyhow (and I see that you will not be joining him down that path!).
    (FYI - I moved that $1,000 system to my next car - coincidentally also a $500 car. And I moved the 300-400Nm engine (2k-3k RPM) with it as well. What are looks when you have class and great systems. Mind you, the engine helps LOL!)

    Bit I'll check more later.
    I don't remember the bigger battery bit - I presume for extra reserve.
    I think I mentioned a voltmeter (across the battery)....

    And yeah - I like the "Ig Switch". Nothing like manual controls. (Just don't forget to turn off!) But that can be modified later - maybe using 2 batteries etc....



  6. #16
    Newbie GiorgaKiSs's Avatar
    Join Date
    Feb 2010
    Greece, Thessaloniki
    hehe....definitely not going down at your....." fellow (car) club member " way! You are funny guy OldSpark! The pleasure is all mine speaking with you guys!

    VERSIONS added !

    I do have the capacitor but a friend of mine wants it for his soundsystem. As i said before i was planning to go big with my sound system that's why i bought it. I think a bigger (Ah) and newer battery is better solution than a capacitor. What do u say ?

    FYI = For Your Information ?

    LOL about your situation i'm in exactly the same car didn't cost more than 400€ (~550$) here in Greece and i have an audio system same class with you......around about 1000€ ! Anyway......we know better......let others think whatever they want!

    I think I mentioned a voltmeter (across the battery)....
    Help me a little bit with that..... U mean to have sth like this to show me the current volt ?

    Question : The ignition command needs a simple "click" of power (just like our home PCs) or it needs continuous power for powering up the PC ?

    EDIT again
    The link to my signature is considered as spamming ? If yes tell me asap (hehe i know a lil' bit non-common words) to remove it !

    EDIT 3rd time (jeez stop it!)
    Why my signature is not visible ?

  7. #17
    Raw Wave
    Join Date
    Nov 2009
    Yep - FYI = For Your Information. (sorry! but please do ask - better sure than misinterpreted.)

    Good about the cap. I thought "don't waste it", but as I have written elsewhere - a common 12V-7AH AGM/VRLA (Absorbent Glass Mat aka Valve-Regulated Lead Acid) battery if far cheaper, and more effective. (You can sometimes start cars with it!).
    And even better if get a bigger "audio" battery - ie, keep the normal/standard battery in the engine bay, and the "new AGM" batter you "need" for you load or audio goes next to the amps - usually in the boot.
    (Hence why sealed AGM/VRLA batteries - not only do they have under half the ESR (Resistance) of common wet lead-acid batteries, but they are (semi-) "sealed" so as to minimise Hydrogen gas (and others) leakage, and also as required by law (or safety common sense) in many or most countries.

    So instead of replacing your original battery with a bigger one, you could add a second instead. (AGM; say just 1.2AH to replace a "capacitor", though usually for twice the price you can have the ~6-times "bigger" 7AH battery. Else it could a similar size to your existing battery, or as big as you want or can afford.)

    And I should be linking to existing threads/posts to avoid repetition... but I haven't kept track....
    But my preference with two (or more) batteries is NOT to permanently join them (in parallel), but to parallel them ONLY whilst charging.
    IE - a "charging sensor" energises a relay that connects the primary/original/main battery (and hence alternator) to the secondary/auxiliary(/stand-by?) battery.
    The "charging sensor" can be a voltage sensor (eg, "above 13.4V") but a standard charge-lamp circuit is often the simplest - and free - you merely connect the relay's coil between the charge lamp wire (usually from the alternator/regulator) and ground/chassis so the relay is on when the ignition is on and charge-lamp off. The relay connects the the first batt's +12V to the 2nd batt's +12V (and both batt- = battery-minus-terminal are ground - chassis/body).
    BUT - each end MUST have a fuse or circuit breaker as close as possible to its battery in case the cable shorts to ground (which can happen either side of the relay to either battery can short). (Guess who only fitted the "front" fuse? - and then had the inter-battery cable under the car rubbing against the propeller shaft...!)

    When engine off (or not charging), the 2 batteries are separate so that the PC or audio can flatten the 2nd/aux battery, but yu still have your main battery for cranking (starting the engine) etc.

    Ideally the aux battery should have a low-voltage cutout - especially for AGM batteries as they do not like remaining discharged - it can kill them quickly.
    But so to the main battery if that is all you have.

    Probably the simplest and best/cheapest undervoltage cutout is the MW728 "Battery Guard" (available here for ~AUD$20 = ~13 Euro) though that only handles 10A.
    Bummer eh? Only 10A!
    But it can switch a relay, or many relays!
    So the $20 MW728 controls a 30A or 60A or ???Amp relay and turns it off when the MW728 voltage reaches 11.2V (that's the MW728 specification).
    Is 11.2V too low? If place a diode between the MW728 and it's +12V supply, the diode drops 0.6V to 0.7V - lets say 0.6V - so the MW sees .6V less than the real supply voltage, hence the MW switches off at (11.2 + .6 = ) 11.8V.
    (Other diodes and other tricks can similarly increase the cut-off voltage. Similar tricks are done on alternators to increase their output voltage (except the one-wire types!).)

    It's so much simpler with pictures! But I guess ideas first.
    And things can be added later. You might decide to try as is first, the see if you want a 2nd battery, & whether big or small....
    But it's nice to glimpse or look ahead so you know to leave that extra bit of cable length there i case you add a relay or whatever later. (Build for now, but allowing for the future...)

    A voltmeter "tells you everything" about the state/condition of a battery. Almost.
    But I'll find links etc for that.
    I have a digital voltmeter in the dash of my 45 year old car that measures my main battery's voltage.
    You might want similar for your setup, though if you have a separate 2nd battery (with low-volts cutout), maybe not.
    But they are useful in any car. Forget Ammeters (they are close to useless) - but link link link....

    But maybe you want to use your PC to measure or monitor voltages...?

    I'm not sure about the "ignition command"....
    I was thinking of the home PCs and the pin that needs grounding (AT 11 or 12??) but I thought - or assumed??! - it needed to be held at ground.
    But now you mention it - it makes sense that its a "click" (else it would never turn off - it would keep re-powering). LOL - I found the pin and learned it needed grounding, but that was all. I'm using a PC supply to 12V power water pumps to recycle water...

    But the car supply could be either - there is logic in off with ignition off. Though I prefer on with ignition (ok) but off when I say so - ie, after saving data etc - not because I turned off the ignition but forgot to save.

    But again - I have a solution - a relay that turns on when power is momentarily applied - say Ignition, or a "click" - but doesn't turn off until you push a button. (It's so simple.)
    But later....

    And spamming??? I don't understand, but I see nothing wrong.
    Yet! (LOL!)

    Ah yes - you know LOL.

    And ie & eg or f.ex = "such as" & "(for) example".
    EG: "...different types of tools such as plumber's and electrician's, for example - water spanners and voltmeters"
    = "...different types of tools ie plumber's and electrician's eg water spanners and voltmeters"
    Of course ie & eg should be ie. & eg. because they are abbreviations, but why bother?
    And at sentence start should be Ie & Eg (or is it still ie & eg???) - but I prefer IE & EG 'cos (because) I think it is less ambiguous. Is Eg a mispellt Egg?

    But your English - no problems! In fact, very good. Burger that - it's excellent!
    I could add maybe 2 or 3 words (prepositions) to "correct" your English, but hey - have you read other "mother English speaker's" posts!? Or mine - especially after my "keys that were NOT pressed hard enough" type spelling etc.
    And I don't think I can find a spelling mistake in your last post! (Damn!)
    Yor ekspreshun is egg-sell-lent, an if wee hav trubels, wee wil arsk to klarify.

    And great - I just spotted you link to the voltmeter.
    Yep - that's the idea. But hey - please take it easy on the bling! (LOL!)
    Though seriously, I'd argue a plain "non-attracting" digital display (with one decimal point - eg 13.6 - not 13.68 etc) but maybe with amber (orange or yellow) and red lights/LEDS that alert to "off normal".
    Typically maybe yellow = under 12V, green = 12 to 14.4, red > 14.4
    Damn nice voltmeter at that link, But I do wonder if its to "loud" and hence annoying, or that you tend to ignore it....

    But now it's nighty-night time. Not that I wear a nightie of course!

  8. #18
    Newbie GiorgaKiSs's Avatar
    Join Date
    Feb 2010
    Greece, Thessaloniki
    OK, about battery, I liked the connect or disconnect when ignition is on or off. But we can see that if i will need it in the future! For now i 'll start with buying the bigger capacity battery i mentioned Bosch S4 74Ah and keep her as my main and only battery.

    Instead of using all that relays and second battery etc. i could alternatively use a switch like this one, located right under the steering column, where the power wire (for amplifiers, car pc, etc) passes through. It will make my Jetta look like a racer or sth! hehe!Which is sth ...... i kinda like! It's a good solution i think, but the problem is i don't know how much A power it can handle..... I just found one (same as photo) in my tools case but it doesn't says any info on it. Neither on the box! (weird huh ??). In case this solution works i prefer this than having a 2nd battery and connectors and relays and and and and !!! I'm waiting for your answer!

    Definitely this photo of the volt meter was random after i googled searching for one! Probably i 'll put a digital one somewhere near the instruments. I don't like much blinky-blinky stuff.

    I don't want the pc to meter my car voltage....i prefer a seperate one.....e.g. if i want to see the voltage i'll need to power up the pc and wait to startup.......load windows......load drivers....load startup programs.....load the final program so i see the thanks!

    Hehehe, you and your relay solutions! i don't want car-pc to have any connection with the ignition of the car. That's a fact. I did ask you so I can decide which switch type to buy. A "click" one (like reset button) or a "ON/OFF" one? I assume that is a very little amount of power needed for the power supply just to understand and start using it's commands for powering up the car-PC. right ?

    And I don't think I can find a spelling mistake in your last post! (Damn!)
    hehehehe! Proud of me !!!

    Yor ekspreshun is egg-sell-lent, an if wee hav trubels, wee wil arsk to klarify.
    Laughed to death! hahahahahahahah
    _=_ VW Beetle 1303LS _=_

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