ITPS Regulation

**Ricky327** · 01-26-2004, 08:18 AM

Adamis,

You said the right combination of component must be used for the ITPS to work, no 12V devices...ok thats fine. Thats exactly how my setup is.

You also said the regulator is for car use, true as along as you dont use the 12V supply.

Now tell something...what the heck is the LM1084 doing in that ITPS when the whole setup cannot work as soon as you put a 12V device, when the supposed to be 12V is well below this during normal operations?

All "NewTechFool" is doing is showing us how the ITPS behave during loading at different voltages. Its up to those poeple in here to decide if this is suitable for them or not. We should be thankful he even bother to post for all to see. But as you can already see it the 12V supply is out of spec. This out of spec 12V supply may work for some and thats probably because they are lucky, how reliable is it? what if you have a bad battery?

The LM1084 regulator was there for a reason...but for what reason when it cant be used with any 12V device unless your car is supplying 13.8V atleast. The ITPS designer must be somehow wishing the 12V supply will work in the car. But as you and others already proved and said it just simply wont work properly.

From your recomendation you are basically saying the ITPS should only be used as a shutdown controller. Might as well bypass the regulator in this case to reduce heat. The ITPS might as well be redesigned as a shutdown controller only...the ITPS should cost even less now.

True I may not own an ITPS but I know more than enough about it to make a comment...probably know more than most poeple in here in a very technical way. Like what "shakes" said we are not trying to put down the products. We are just naturally interested in such subject and post our finding for others to decide whats its limitations are...wishing we can put all our findings together and put the issue to rest.

The point some guys are making is...the regulator part of the ITPS is useless...said in a technical way...as "none" said so too in a short word. I dont know if you done any testing as "NewTechFool" but I do appreciate his post. It may not be 100% accurate in what he said but if you think that is then just correct him. After all we are here to help each other out.

**Ricky327** · 01-26-2004, 08:26 AM

These finding should go in the newbies FAQ sections soon so we dont keep going around in the circle.

Just like the CAP vs BAT tank circuits discussion with "shakes", "none", me and others

**shakes** · 01-26-2004, 10:35 AM

Originally Posted by Ricky327

These finding should go in the newbies FAQ sections soon so we dont keep going around in the circle.

indeed. it should also be noted in the faq that the ITPS will limit you to 60W. that's what most newbs don't understand ... they think as long as they have a PW-70a they'll have 100w+ to play with ... and that simply ain't so

Originally Posted by Ricky327

Just like the CAP vs BAT tank circuits discussion with "shakes", "none", me and others

ha!

**adamis** · 01-26-2004, 02:48 PM

If I recalled correctly when I talked with the company that produces the ITPS and the PW powersupplies I was told that the PW-70 was limited to the 60 watts and the PW-70A is 100 watts, at least that's what I understood what they said about the power supplies. Perhaps an e-mail to Ituner could clear this one up...

Second the ITPS as designed and if used with the recommended equipment will not have problems. If you are buying a product it is important to read all of the information you can on it including forums and threads like this.

Ituner recommends using laptop components for power consumption as well as power issues. The advantage to running an ITPS and a PW-70 power supply is the savings in space. My whole setup fits into a double din case. I couldn't do this with a desktop harddrive so I used a laptop harddrive and as a result the ITPS and PW-70 work in my situation. I am aware that not everyone's situation and needed space requirements are like my own situation.

It is also important to inform people who perhaps are considering useing the 12volt rail for a harddrive that desktop harddrives are not designed for mobile environments and thus might not take the abuse that a laptop harddrive is built to withstand. Also running a 12volt item such as a desktop harddrive with the ITPS is probably playing the odds and I wouldn't try it so if that's what you plan then stay away from the ITPS and PW-70 power supplies.

My point here is that if a newbie comes along and reads the claim that the ITPS is not good for automotive use while not qualifying the statement or explaining with what components this holds true to could be taking a viable and cost effective solution for that newbie away. That is what my concern is about.

**shakes** · 01-26-2004, 03:30 PM

Originally Posted by adamis

If I recalled correctly when I talked with the company that produces the ITPS and the PW powersupplies I was told that the PW-70 was limited to the 60 watts and the PW-70A is 100 watts, at least that's what I understood what they said about the power supplies. Perhaps an e-mail to Ituner could clear this one up...

This is correct. However the LM1084 Regulator the ITPS uses maxes 5a at 12v so even with the PW-70a you can only get 60w to your system if you use the regulator on the ITPS.

I'm starting to think myself of bypassing the regulator on the ITPS. Even though mini-box says the M10000 doesn't use 12v if you don't have any such components it still makes me a little uneasy.

But I'd like to run a powered USB hub off my PS so I don't have to use another regulator ... my system currently runs around 3-4a and i'm afraid the USB hub may take me over the 5a max of the ITPS.

eh ... i need to do some more measurements and see what hub i decide to use. I'm really thinking about going unregulated tho.

**none** · 01-26-2004, 03:30 PM

Originally Posted by adamis

If I recalled correctly when I talked with the company that produces the ITPS and the PW powersupplies I was told that the PW-70 was limited to the 60 watts and the PW-70A is 100 watts, at least that's what I understood what they said about the power supplies. Perhaps an e-mail to Ituner could clear this one up...

His point was that this is not true when these PSUs are combined with the ITPS. The ITPS becomes the limiting factor here, feeding the PW-70a only 60 watts to begin with. It can't make power, only regulate it, so it's maximum output is something somewhere below that input.

**shakes** · 01-26-2004, 03:31 PM

i beat ya to it none

**Ricky327** · 01-26-2004, 03:43 PM

I'm starting to think myself of bypassing the regulator on the ITPS. Even though mini-box says the M10000 doesn't use 12v if you don't have any such components it still makes me a little uneasy.

Ill make sure unregulated 12V supply never reach the motherboard. I guess you can do this by cutting the 12V track on the PW70 that goes into the motherboard if you want peace of mind

Also just incase a MB HW revision is made that make use of this 12V supply again...atleast you know the board cant blow.

It still puzzle me why the ITPS/PW70 cant survive a crank when you dont even use a 12V device. All you need is the 3.3V and the 5V, surely the car supply dont go that low during crank. From what I can see the ITPS/PW70 can be made to survive a crank as long as you dont use the 12V supply. This make a good solutions for car pc builders.

**shakes** · 01-26-2004, 03:53 PM

Originally Posted by Ricky327

It still puzzle me why the ITPS/PW70 cant survive a crank when you dont even use a 12V device. All you need is the 3.3V and the 5V, surely the car supply dont go that low during crank. From what I can see the ITPS/PW70 can be made to survive a crank as long as you dont use the 12V supply. This make a good solutions for car pc builders.

you know it doesn't really make sense to me either ... alls i know is i helped a guy with an install recently with an ITPS, PW-70a, M10000, laptop HD and CDROM and it would reboot during crank???

i haven't actually plugged mine up yet but i'm assuming it will do the same and will install a tank just to be safe if nothing else.

**Ricky327** · 01-26-2004, 04:01 PM

you know it doesn't really make sense to me either ... alls i know is i helped a guy with an install recently with an ITPS, PW-70a, M10000, laptop HD and CDROM and it would reboot during crank???

Yes...but maybe it had to do with the minimum operating voltage of the PW70...as thats the only thing that regulate the 3.3V and 5V. A variable voltage PSU connected to the PW70 will tell us what really is going on

Althought the tank circuits has been more or less fully understood, but its abit hmm ugly