Battery based tank circuit (tested) - Page 6

none · 02-18-2004, 10:18 PM

Quote: Originally Posted by LESLIEx317537

OK, so what's the best power supply out there?

This is what I have been running for 2 years with Jeff's shutdown controller. It says min in is 9 volts, so why does my PC reboot on crank?
http://www.keypower.com/proddetail.a...&linenumber=15

How is it connected to power? What gauge wire, how long, what fusing, what kind of connections? How is it grounded? Have you measured voltage in your car while cranking?

none · 02-18-2004, 10:25 PM

The Keypower is actually one of the PSUs shown to benefit from capacitor based tank circuits, but I don't mention those anymore out of fear of being flamed like hell. http://www.mp3car.com/vbulletin/power-supplies/6363-help-tank-circuit.html

Ricky327 · 02-18-2004, 10:38 PM

Won't the resistor drop the voltage going into the backup battery also?

Yes this will naturally happen when the backup battery is flat and need alot of current to charge up. The resistor is there to limit the current going into the battery and this is exactly what we want.

Looking at the original circuit, it is possible to remove the lower diode on the diagram and replace it with a wire. The good thing about this is the backup can provide the full voltage into the PC as theres no more voltage drop caused by the lower diode. The downside is the battery cannot be fully charged up when the PC is running since the PC will take down the charging voltage of the battery with it. Also the charging current is not limited properly since the battery will try to get the charging current directly from the upper diode. But I guess this might work better on some setup.

You can run diodes in parrallel to acheive more amp loading.

Yes Im aware of that, but the circuit was orignally designed for my low power laptop so I wasnt so concern about the more than 3A diodes. As I mentioned it before the design can easily be modified to work with higher current...for those who like to use inverters.

Ricky327 · 02-18-2004, 10:43 PM

Besides, making your own stuff is fun. Sometimes I don't feel like buying premaid stuff. I'ma do it myself kind of person. I change my own oil, why not go to Jiffy lube, You goto Jiffy lube or your dealer, I'll do it myself. It's part of the fun part, building and learning and posting questions on this forum

I agree...making your own stuff is fun. I also used to fly model planes and build it from the plan. Same with the model cars with petrol engine I used play with them alot. Yup buying premade stuff is simply boring, designing your own things and building it is far more interesting than just putting them together...even though it may or may not work, the point is you learnt something...how can one learn when they havent even tried. I just sometimes find it strange when one ask for advice and they give something like...buy an OPUS

... A question come up "Im building a car but im having problem with..." Do I hear a response something like "go and buy a car instead its much easier to do"?

Sure it is but this is a hobby.

Oil change...do people really have to ask someone to do it for them? I can understand if the task is impossible or a specialised tool is needed. Beside those garage that change oils dont even flush the engine properly...all they do is suck out the oil. New oil but with all the sludges still in the sump. Just watching them do thier jobs make me wanna scream, some cant even turn a screw.

Ricky327 · 02-18-2004, 10:46 PM

The Keypower is actually one of the PSUs shown to benefit from capacitor based tank circuits, but I don't mention those anymore out of fear of being flamed like hell

Im not even gonna bother...we came up with a conclusion with this one. I dont know about "shakes" though

none · 02-18-2004, 11:07 PM

"Conclusion" it is not, just your theory. To use your tactics against you, show me your "proof" that it doesn't work. I mean hardware (Keypower in this case,) not equations.

Ricky327 · 02-18-2004, 11:53 PM

The Keypower is actually one of the PSUs shown to benefit from capacitor based tank circuits.

"One of" > you are even admiting the capacitor wont work on some setup, why? If the capacitor is so great why cant it work with any setup? Just because one guy got it to work on one setup it dont mean it will work on others. I do hope you realised by now why only some PSU can survive a crank with a small capacitor. If someone is using an inverter with a bad battery what will you tell them to use? a capacitor or battery?

If thats the sort of PSU he got then yes thats good for him if everything can be solved with a capacitor as you adviced. But Im not even gonna prove if that PSU can survive a crank or not in reality or theory because it already say on the thread it can operate down to 9V...most PSU just doesnt operate this low.

But dont you think these PSU designer should already be putting this capacitor in their circuit to survive the crank at the first place? Maybe its about time they realised this cranking problem, someone got to tell them that this where they been going wrong

LESLIEx317537 · 02-18-2004, 11:58 PM

So far Opus is the only manufacturer (Big time) that advertises crank protection.

Anyone look to see if they got caps?

I'm gonna voltmeter my car during crank. I got thick wire, my car is brand new and nothing is wrong with the wiring. The only thing is I do have a dumb light switch toggle for power. That may be voltage drop.

But... also I built two carpcs recently that need crank protection. A PW-70A powered setup and mine. So I'm trying to kill 2 birds with one stone.

none, whats with you and this thing against people building tanks and stuff? You obviosly got a reason to hang around here if your PC is not rebooting since you have a Opus. Is there some insite you have besides running big thick wire? How many CarPC's have you built? I've built 3 so far and they all need some sort of crank survival.

Ricky327 · 02-19-2004, 12:28 AM

none, whats with you and this thing against people building tanks and stuff?

It had something to do with this thread :

http://www.mp3car.com/vbulletin/power-supplies/20279-those-who-tried-1f-tank.html

Have a read

none · 02-19-2004, 01:48 AM

Quote: Originally Posted by LESLIEx317537

none, whats with you and this thing against people building tanks and stuff? You obviosly got a reason to hang around here if your PC is not rebooting since you have a Opus. Is there some insite you have besides running big thick wire? How many CarPC's have you built? I've built 3 so far and they all need some sort of crank survival.

I have two systems, both with Sproggy 2.8+, both having no problems surviving cranks. I have nothing against building tanks, I was merely trying to point you to some information relevant to your situation. I have always agreed that capacitor based tanks are useless for ITPS/PW70 use (or inverters for that matter) as this is just a poor PSU design to start with. As the manufacturer recommends in the ITPS manual, a battery tank is best in that situation. But capacitor based tank circuits have been proven to work with other DC-DC PSUs, including yours, and have size and simplicity advantages. Do what you will with that. Sorry for trying to help.

Ricky,

Obviously the Keypower needs some work, that's why the Opus is spanking it. (Go work for them and fix it

) And as I've told you before, it's not a voltage issue, it's a current issue.

LESLIEx317537 · 02-19-2004, 11:10 AM

Yes, but the KeyPower puts out 250 watts while the Opus puts out 150 watts.

The Opus allows 5amps max on the 12 volt line. The KeyPower allows 12 amps. I got my touchscreen running off the PS and also a 7200rpm drive plus more. Can the Opus handle the load I throw it?

I may just buy a Opus if this is easier. No way am I gonna build the sproggy for 100 buks when I probably will never get all the parts. -Also how many amps can the Sproggy handle?

Alessio · 02-28-2004, 10:56 AM

Guys, can all this be done with a DC to AV inverter an a very small UPS? I am trying to avoid all this work, since I am not that good with advanced electic circuits (dont laugh, this stuff is advanced for me

Thanks

LESLIEx317537 · 03-28-2004, 04:40 AM

I can survive cranks without a backup battery and I use a 250 watt Keypower. Read more here: http://www.mp3car.com/vbulletin/show...949#post180949

zvi · 04-02-2004, 09:23 AM

I just finished a setup of the proposed (first post) circuit with 8x1N5822 diodes, 5 watt 15 Ohm Resistor and 9Ah SLA Accu. I put 4 diodes per each line (on the diagram) to have capacity of 12 amp (may I will not need so much) to pass through

I did not test with PC, but multimeter shows:
With engine off: 12.35v
When cranking: 12.10v

Without tank circuit it is 12.35v/11.7....something

I am sure, PC will survive crank, but I am afraid with load, that PC will give, voltage drop will be more, waht do you think?

Alessio · 04-02-2004, 09:39 AM

Quote: Originally Posted by zvi

I just finished a setup of the proposed (first post) circuit with 8x1N5822 diodes, 5 watt 15 Ohm Resistor and 9Ah SLA Accu. I put 4 diodes per each line (on the diagram) to have capacity of 12 amp (may I will not need so much) to pass through

I did not test with PC, but multimeter shows:
With engine off: 12.35v
When cranking: 12.10v

Without tank circuit it is 12.35v/11.7....something

I am sure, PC will survive crank, but I am afraid with load, that PC will give, voltage drop will be more, waht do you think?

Too technical for me .... but there seems to be only one way to find out