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Voltage stabilizers?

Discussion in 'Gen 3 Prius Technical Discussion' started by Stratman, Apr 19, 2014.

  1. Stratman

    Stratman Member

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    I've been reading the claims on these things. Increase in mpg? Increase in torque? As a 30+ year schooled electronics guy, I could maybe see it keeping the lights from dimming when those 1000 watt (insert eye roll here) subs kick in but I can do that with by beefing up the amps power supply section with a bigger res. cap or adding another filter cap stage, or just doubling all the caps down the line past the res. cap.

    Any truth to the hype on these things?
     
  2. vskid3

    vskid3 Active Member

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    Do you mean the little ones that plug into your cigarette lighter port? Because those are garbage. Even if they did work on cars with an alternator, I'm sure the Prius' DC-DC converter produces much cleaner power as is.
     
  3. David Beale

    David Beale Senior Member

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    The easiest way to find out is to buy a capacitor and install it. I'm talking about the ones rated in Farads and used in super audio installs. I put one on a 3rd gen RX-7 and it helped it. But that car was well known to have an "iffy" electrical system.

    I doubt very much it would have a noticeable effect on a Prius. But try it. For under $50 you will know for sure. DO install it at the main fuse panel under the hood (drivers side), and DO install it on the main power feed line, not on a branch circuit. The "boost point" would be a good place.
     
  4. Robert Holt

    Robert Holt Senior Member

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    I assume the main power feed line would have the 500+ volt current from the inverter running through it? Installing a multi-Farad capacitor on that line could be interesting if one ever accidentally touches both terminals. But "interesting" is not always good.
     
  5. Stratman

    Stratman Member

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    I did something very similar once. I built a deterrent to keep my cat off of my turntable. It looked like a miniature boxing ring. The corner posts were nails covered with shrink tubing. I wrapped two bare solid core wires loosely about 1/2 inch apart around them. Then rigged up an old cross bar pbx system transformer I had lying around and paralleled 2 300k uf 1000v caps for my power supply. I built in a 3 sec. Charge time so my cat could get away when she jumped up there. She hit it one time and that's all it took. It was only 52 volts but packed a heck of a pop when it shorted.
     
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  6. David Beale

    David Beale Senior Member

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    No, I'm talking of the 12V system. LEAVE THE TRACTION SYSTEM ALONE!! All you can do to it is mess it up or kill yourself trying!
     
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  7. Robert Holt

    Robert Holt Senior Member

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    The SPCA will shortly be at your front door to interview your cat!
    (Very inventive. My college gang used a Model T ignition coil and hot wired the toilet seat in our dorm's bathroom. Fortunately it was low amperage so no one was killed, but it was sufficient volts to shock the bejesus out of anyone sitting on the commode. Ah, the good old days.)
    Apologies to OP for getting off topic.
     
  8. Stratman

    Stratman Member

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    Good eye catching that!!! I read right over it. I should re-read my presentation on Active Listening. I automatically assumed he was talking about the 12v system. Big no no on my part.
     
  9. A617

    A617 Member

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    Your going to need a HUGE CAPACITOR some around the size of the Mazda I-Eloop to see any benefits on reduction in the use the alternator, and besides our car don't have an alternator and we receive our power for our battery from Hybrid power train and it varies on its charging. So dont waste your time on buying it.

    PS that voltage stabilizer thingy capacitor is a size of an Advil gel Capsule so its effectiveness is around 0.000000000001% or non existence... in fact it draws power to light up the led bulb.
     
  10. David Beale

    David Beale Senior Member

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    First, you can get one or two FARADS for under $50 from the wacko audio crowd. So it isn't expensive or large at all. Yes, one or two farads is a very large capacitor. They do have an effect if you are adding crazy audio systems. The effect is to "bypass" small resistances in the 12V power feed line (they store energy at low rates of use and release it very quickly, stopping or reducing voltage drops).

    Second, in a car with a poor electrical system they can have a noticeable effect in how it runs. I've experienced poor grounding in a few cars that caused them to function poorly in some situations. It's -possible- that could result in fuel economy effects.

    Finally, I see no reason to think Prius has a poor electrical system, but if you really want to test it's inexpensive (<$50), easy (attach to the boost point with large cables and good connections), and unlikely to cause any problems as long as you don't short out things and keep the polarity correct. Do keep in mind there is a largish capacitor at the 12V battery already, but the cable from the battery to the fuse box under the hood probably has some measurable resistance and it's -possible- bypassing the effect of that resistance could be beneficial.

    Without proper measurements I won't listen to pro or anti arguments. Test it and see. :)
     
  11. Easy Rider

    Easy Rider Active Member

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    If one used that philosophy for every "snake oil", over-hyped scam that you came across, it would cost you a small fortune.......and make the scammers VERY happy.

    My advice:
    The car runs fine without ANY of that add-on crap.
    Except for an occasional dose of injector cleaner, don't put anything into your gas, oil or transmission, don't connect ANY external devices to anything, don't add or replace any chips and don't change the intake or exhaust hoping to get better "performance".
    ALL of that stuff is useless at best and sometimes actually damaging.

    But then there aren't many absolute freedoms left anymore. One remaining is an absolute freedom to be as stupid as you want.......as long as it doesn't affect anybody else. :whistle:
     
  12. Stratman

    Stratman Member

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    Not a good idea to bypass any resistance. In fact. When I increase capacitance in filtering stages I add a a relatively small value, high wattage resistor. Typically 22uf or 47mf to slow the initial inrush current in front of the source. When you add huge value caps across a voltage source it is essentially a dead short till the cap charges. If it were me, I would just parallel another battery of equal voltage across the existing one and be done with it. I originally asked if these things worked because I knew they weren't physically large enough to be an electrolytic.

    If I had to do any of the above to a Prius, I would forgo something with such a high current demand. I would also question the quality of a 1 farad cap that only costs 50 bucks. My cost on 4 or 5 good quality 20uf 500v caps is that much. If you're lucky, when it shorts, it will blow into bits of gray paper and foil before the source does.
     
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  13. qdllc

    qdllc Senior Member

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    But you might get noted as a Darwin Award recipient. :sneaky: