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Discussion Starter #1
I have a pretty extreme 1200hp V8 Porsche Cayman I built. More on that here

Instagram.com/jordon.musser/

Long story short is that the voltage dips quite low on on start which causes my JL TWK to wig out, lots of the time defaulting to no tune, and I think I actually damaged one because of it. In lieu of fixing that I wanted to look at putting a small voltage regulator (more of a DC to DC converter) for just the TWK since its low power anyway.

Anything out there that is off the shelf?
 

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I have a pretty extreme 1200hp V8 Porsche Cayman I built. More on that here

Instagram.com/jordon.musser/

Long story short is that the voltage dips quite low on on start which causes my JL TWK to wig out, lots of the time defaulting to no tune, and I think I actually damaged one because of it. In lieu of fixing that I wanted to look at putting a small voltage regulator (more of a DC to DC converter) for just the TWK since its low power anyway.

Anything out there that is off the shelf?
Something like a capacitor and a diode?

Probably more like:
power --> diode --> capacitor --> TWK

?
 

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Discussion Starter #3
Ya, properly sized that would probably do it. Not an EE, so might take me awhile to size it. Plus cap might get big. Wasn't sure if there were any actual regulated supplies (like the product has onboard for that matter!) that would work in this application
 

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Ya, properly sized that would probably do it. Not an EE, so might take me awhile to size it. Plus cap might get big. Wasn't sure if there were any actual regulated supplies (like the product has onboard for that matter!) that would work in this application
- What does the JWK draw?
There are probably some sites that can allow you to find the size required.

  • How long does it take to crank over?
  • A few seconds?
 

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So R ~= 2.0 ohms.
T = 2 seconds

 

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That brings back some memories. Need to calc capacitance too.
You know Vo is 12V, and whatever the JWK says for minimum voltage (probably 9V ?).
And you also know T and R, so just solve for C...
 

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I’d look at the small 58f super cap bank from Maxwell that comes pre built with balance board in a moulded chassis, they should keep your voltage a fair bit more stable, maybe even without a diode in series... you could even put a relay in series energised by the starter switch so the relay disconnects the cap bank and processor from the battery completely as a 58f super cap bank will likely run the processor for a fair while, it’s something you need to play with and see what works best, a diode in series may be ok, but it would need to be a fair size if the processor draws say 2a continuously...

a few choices there
 

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I was thinking 1/2F would be overkill.
 

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I was thinking 1/2F would be overkill.
It would if dioded, but I was trying to avoid the voltage drop from the diode... the 58farad bank may also benefit the amplifiers overall performance 👍🏼 Hence my relay idea
 

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But I think it was only for the amp to avoide loosing its mind when starting the engine?
 

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But I think it was only for the amp to avoide loosing its mind when starting the engine?
I was thinking five steps ahead... It is only a processor so not even an amplifiers current draw, hence my thought that a decent sized cap bank in general would help the device not shut down, and be of benefit to the system overall...

but I did also say a smallish cap on the power supply with a diode would work, it would need to be a big diode however as it will invariably end up buried beneath some trim and be passing 2a while dropping 0.7v from the supply voltage also...
 

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It is a 1200 HP Porsche Cayman.
I suppose a radio makes more sense in it than in a GT3
 

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Discussion Starter #16
They kind of work in concert. When I am cruising at light throttle, I hear wonderful music. When I am at full throttle I hear other types of wonderful music :)
 

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Discussion Starter #17
Although that supercap looks pretty cool, not sure it will work. The starter will be drawing from the same source, although perhaps it would be enough to eliminate the problem.

Also its a big dude :)
 

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What is cranking voltage? is battery big enough for engine size? what battery PN or group size?
How much room do you have(at the battery) and/or at the JL mounted location?

You can add a 2nd battery(smallest 12v you can find and maybe isolate it).
You can add a small ultracapacitor(they make them from 1F to 3400F). So, a 6-pack of 5-100F Eaton/Maxwells really isn't all that big. But, you'll want the power line to the JL to have a diode(check valve) to keep the small ultracap from feeding the battery/starter.

Or, you can make a bigger 100F-3400F 6-pack and connect it to the battery. This will prevent the voltage drop as it will can start engines all by itself.

And, when using 6 capacitors in series, you build a pack with divide by 6 capacitance. So, a 3000F wired in series 6-pack provides 500F.

Shop at mouser if you fear knock-offs on Amazon/ebay

A 25F Maxwell is 1" tall and 5/8" diameter. A six pack(inline, flat6 or vr6) would take up minimal space and add minimal weight. Maybe cost $40 and a few minutes to solder and shrinkwrap and connect to power leads of JL.

AGM powersonic PS-1212(or anycompetior) is 4x2x2".

Some picks of capable capacitors for your JL. You will need a 5 or 6 pack depending on peak charge voltage.
60Fx6.jpg
275270
 

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Although that supercap looks pretty cool, not sure it will work. The starter will be drawing from the same source, although perhaps it would be enough to eliminate the problem.

Also its a big dude :)
The small 50odd farad bank is only 12” long maybe... and 2”x1” so not big at all...
 
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