Generator

Scott Johnson · **Posted:** Wed Aug 25, 2004 1:04 pm

Mike covered most of it, though we will just have to agree to disagree about the simplicty of a generator.

Otherwise, the biggest issues we seem to face are "cheap" electronics. Crummy 2nd hand amps, crummy 2nd hand inverters, and some aging bus wiring.

We could get by with any one of the problems, but not all. Before we do anything other than charge the existing batteries (anyone want to volunteer to haul them around every event?), we need to get all the other issues worked out. Look for updates in that department in the near future!

Scott

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

scottjohnson wrote:

Mike covered most of it, though we will just have to agree to disagree about the simplicty of a generator.

Otherwise, the biggest issues we seem to face are "cheap" electronics. Crummy 2nd hand amps, crummy 2nd hand inverters, and some aging bus wiring.

We could get by with any one of the problems, but not all. Before we do anything other than charge the existing batteries (anyone want to volunteer to haul them around every event?), we need to get all the other issues worked out. Look for updates in that department in the near future!

Scott

DickRasmussen · **Posted:** Wed Aug 25, 2004 2:40 pm

In regard to a generator, IF that ever turns out to be needed, you may want to consider a "built in" RV genset and converter/power center. Properly installed including an exhaust system (with tall pipe to keep the fumes away from the bus) and sound insulation it might be the optimal solution. Plumb the fuel line to the bus engine line and the problem of keeping a "Honda, etc." generator fueled goes away. So does the need for extension cords, etc. Could even reduce the battery capacity needed and could even be wired to recharge the bus's engine battery during events if that is an issue. Once you do that you could even power an RV airconditioner, RV refrigerator, Microwave, etc.

Not cheap but MIGHT be worth it.

Dick (with LOTS of money spending ideas)

Chuck Frank · **Posted:** Wed Aug 25, 2004 7:47 pm

Adam Ligon wrote:

Yeah and everything went perfectly at Rockingham. Makes you think the problem isn't as simple as people are making it out to be.

Actually it didn't. There was a lull in the action during the second heat when the computer suddenly went dark. I was told (I was volunteer announcer at the time) that it was a power issue. My HP Ink Jet printer runs on 12v. (I think, I'd have to look on the power brick to be sure, but it's definitely not 110V going through that little wire.) New low voltage powered printers can be had for < $65.00.

shawnwhipple · **Joined:** Wed Aug 20, 2003 6:28 pm **Posts:** 603

Here is what I think we have left to solve.

PA drawing down supply voltage to ~10.5 VDC

Laptop charger overloads the inverter (sometimes) thus the laptop doesn't get charged and dies. I think there has to be a better solution than what we currently do since we take 12DCV convert it to 110AC and then the power brick converts that back to some DC voltage (18VDC?) We should be able to get a DC to DC power supply for the laptop and same thing for a printer.

As other people have said the bus doesn't have a power supply issue, it's all the stuff that plugs in the the bus that needs to be repaired.

And just for the record, I'm not opposed to getting an alternate power source at some point in time. We need to get everything fixed first then decide what we really need.

Shawn

ps. The display issues are fixed (crossing fingers).

John Hines · **Posted:** Wed Aug 25, 2004 9:26 pm

I have several generators available....gas and diesel....5kw to 50kw...some are installed in trailers some are light portables...you need a generator I can hook you up. Most utility vehicles have a generator mounted somewhere under the frame...we can do that with a little creativity. Large capacity isolators and voltage inverters are also available...You can also run air conditioning systems with generator power. A good RV AC unit is expensive though.

George Bright · **Posted:** Wed Aug 25, 2004 9:57 pm

Here is a possible solution to laptop power supply problem. Here is a 100W 12V to 15V-21V supply. It should also work for future laptops too.

http://www.cyberguys.com/templates/searchdetail.asp?T1=141+0170

No it is not a naughty site. :lol:

Chuck Frank · **Posted:** Wed Aug 25, 2004 11:10 pm

George Bright wrote:

Here is a possible solution to laptop power supply problem. Here is a 100W 12V to 15V-21V supply. It should also work for future laptops too.

http://www.cyberguys.com/templates/searchdetail.asp?T1=141+0170

No it is not a naughty site. :lol:

Cyberguys have some Kuhl gizmos you don't see anywhere else. A candy store for geeks.

AndersGreen · **Posted:** Thu Aug 26, 2004 7:38 am

shawnwhipple wrote:

I think there has to be a better solution than what we currently do since we take 12DCV convert it to 110AC and then the power brick converts that back to some DC voltage (18VDC?) We should be able to get a DC to DC power supply for the laptop and same thing for a printer.

Just as a little bit of education:

Any DC to DC power supply that goes UP in voltage does so by converting to AC and then back to DC.

Now, there are certainly different devices that use frequencies other than 60 Hz, voltages other than ~120V, and devices that have different efficiencies, and so on. But they all use that method. So while a custom device would mean that you plug it in to 12v somewhere and not the inverter, we shouldn't mysteriously think that we've gained any magic: we've only purchased a specialized, dedicated inverter that probably won't work for our next laptop.

I'm not saying that there's *no* reason to get one, just that we should get one for the right reason.

Anders

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

AndersGreen wrote:

shawnwhipple wrote:

I think there has to be a better solution than what we currently do since we take 12DCV convert it to 110AC and then the power brick converts that back to some DC voltage (18VDC?) We should be able to get a DC to DC power supply for the laptop and same thing for a printer.

Just as a little bit of education:

Any DC to DC power supply that goes UP in voltage does so by converting to AC and then back to DC.

Now, there are certainly different devices that use frequencies other than 60 Hz, voltages other than ~120V, and devices that have different efficiencies, and so on. But they all use that method. So while a custom device would mean that you plug it in to 12v somewhere and not the inverter, we shouldn't mysteriously think that we've gained any magic: we've only purchased a specialized, dedicated inverter that probably won't work for our next laptop.

I'm not saying that there's *no* reason to get one, just that we should get one for the right reason.

Anders

Interesting. I hadn't thought specifically about that, but I'm sure inverting to higher voltages incurs larger losses...

Anyways, as Tom mentioned on the prior page, he's already ordered two 12v convertors. I'm not sure if the laptop is > or < 12V, but I would bet dollars to doughnuts that the dedicated charger will pull a LOT less current than the invertor deal we use now.

Tom Hoppe · **Joined:** Wed Aug 20, 2003 10:16 am **Posts:** 387

I actually just ordered 2 cables for the existing 12V converter. We apparently melted one back before I was in the club, and we recently melted #2. Because of that I bought an extra inverter instead of this cable. Figured we would use the standard "wall" laptop adapter + inverter instead. That doesn't work though apparently

Now we have two of the cables that we melted, so in case we melt another one, we have an extra

We currently have 3 inverters in the bus. 1 for the printer, 1 that I recently bought, that we were going to use for the laptop, and 1 extra that kinda worked sometimes as a spare. I'll throw that kinda busted one away, and we'll just use the 1 for the printer, and the new one as our spare, with the laptop plugged in with its dedicated 12V brick and new cable.

-Tom

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Tom Hoppe wrote:

I actually just ordered 2 cables for the existing 12V converter. We apparently melted one back before I was in the club, and we recently melted #2. Because of that I bought an extra inverter instead of this cable. Figured we would use the standard "wall" laptop adapter + inverter instead. That doesn't work though apparently

Melted? WTF? I think we may be onto something about our "power problem".

Can I get the laptop this weekend for some current testing?

Tom Hoppe · **Joined:** Wed Aug 20, 2003 10:16 am **Posts:** 387

Quote:

We melted down the 12V plug from our car adapter a few years ago (in 2000, IIRC), and in the process of getting a replacement had a nice talk with a tech guy at Linn, the company that makes the adapter. He said the problem is this:

The adapter is a DC-DC converter, I think it converts 12V input to 15 or 18V output (not sure). Anyway, when the laptop battery gets low, it has to draw proportionally more power from the input to maintain the correct output voltage. And when the input voltage is low (eg. the bus battery is getting low, or we have a bad power connection, then there is an *exponential* increase in the power needed by the inverter to produce the needed output voltage. If the 2 factors are combined, the power adapter can really draw a lot of current, and that's how we melted the power plug.

So, he told me, the solution is simple:
1. make sure the laptop has a good charge already before the event starts (I always try to hand the laptop off with a good charge, but it may not always happen) 2. make sure the bus voltage is good during the event 3. make sure you've got a good 12V power connection.

There is excerpt from a Carl Fisher email earlier this year. They did in in 2000, and then we did it again early this year.

Todd Breakey should have the laptop.

-Tom

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Tom Hoppe wrote:

Quote:

We melted down the 12V plug from our car adapter a few years ago (in 2000, IIRC), and in the process of getting a replacement had a nice talk with a tech guy at Linn, the company that makes the adapter. He said the problem is this:

The adapter is a DC-DC converter, I think it converts 12V input to 15 or 18V output (not sure). Anyway, when the laptop battery gets low, it has to draw proportionally more power from the input to maintain the correct output voltage. And when the input voltage is low (eg. the bus battery is getting low, or we have a bad power connection, then there is an *exponential* increase in the power needed by the inverter to produce the needed output voltage. If the 2 factors are combined, the power adapter can really draw a lot of current, and that's how we melted the power plug.

So, he told me, the solution is simple:
1. make sure the laptop has a good charge already before the event starts (I always try to hand the laptop off with a good charge, but it may not always happen) 2. make sure the bus voltage is good during the event 3. make sure you've got a good 12V power connection.

There is excerpt from a Carl Fisher email earlier this year. They did in in 2000, and then we did it again early this year.

Todd Breakey should have the laptop.

-Tom

Thanks for the info Tom!

Now I'm even more suspicious of the wiring gauge and connections than ever.

Chuck Frank · **Posted:** Thu Aug 26, 2004 1:13 pm

I'd be fairly certain that inverting the bus's 12V DC to 110 AC and then back to whatever the computer uses is a serious power drain. Since as mentioned, there are mobile power adapter/chargers out there for most any computer, using one directly off the 12V would make a lot of sense. We run our laptop for 12-18 hrs off one in our car while traveling and it doesn't even get warm. The only suggestion I'd make is to replace the cigarette lighter plug with heavy duty banana plugs for reliability. two separate circuits off two batteries with isolator and two panels of female banana plugs would be a nice system. I know my way around electronics and LV power distribution pretty well, and would be willing to redo the bus system after nationals.

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