Will 7.2V be sufficient?

sbf · Post by **sbf** » Fri Dec 09, 2005 4:08 am

I have one of those dc dc convertors from Ti, and somewhere I read that they can run on 7.2V on this forum, is this true?

So will a 7.2v RC car battery pack power my Psone screen and n64? or is that not enough voltage for the convertor?

Cheers!

cowsgoquack101 · Post by **cowsgoquack101** » Fri Dec 09, 2005 7:21 am

I think it takes at least 10 volts or something like that... I don't know do a search.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Fri Dec 09, 2005 7:24 am

i think 7.2 will work
G-force got it running on 7.2

MaDnEsS · Post by **MaDnEsS** » Fri Dec 09, 2005 9:45 am

i did to except i got one from digikey i think its the same one though

Post by **Sparkfist** » Fri Dec 09, 2005 10:15 am

The N64 has two voltages; a 3.3v and then it has a voltage line that goes to a 7805 regulator. So if you can get a regulator (needs 2 amp current through-put) that can take the battery voltage to 3.3v you can feed the other into the 12v line and it should work fine.

However if you are ambitious, you can desolder the 7805 and eithe install a LDO IC and use a 6v battery or just by pass the regulator all together. But both of these do run the risk of you frying the board.

sbf · Post by **sbf** » Fri Dec 09, 2005 10:53 am

I wanted to keep the voltage at 7.2v so that I could supply the psone modded screen, I suppose I could increase the voltage and use a 7808 to supply the screen.

I have a texas instuments 2A 3.3v dc dc convertor for the n64.

I was hoping that the convertor would run on 7.2!

timmeh87 · Post by **timmeh87** » Fri Dec 09, 2005 1:25 pm

best way is to just try it. worst that will happen is that nothing will happen. i had mine working on 7.6ish.

Post by **Gamelver** » Fri Dec 09, 2005 1:53 pm

only thing that'd be bad is if you put too much voltage into it...but if it's not enough, then perhaps you could either step up the voltage, or use a NiMh AA with the same capacity to up the voltage.

Post by **Sparkfist** » Fri Dec 09, 2005 4:23 pm

sbf wrote:I wanted to keep the voltage at 7.2v so that I could supply the psone modded screen, I suppose I could increase the voltage and use a 7808 to supply the screen.

I have a texas instuments 2A 3.3v dc dc convertor for the n64.

I was hoping that the convertor would run on 7.2!

Just so you know the PSone screen has 7805 regulators in it not 7808. You can use 7.2v no problem. The things I was trying to get across was that you will have to make a small circuit to reduce the voltage off the battery to 3.3v to supply that to the system board. However other then that you can connect the positive 7.2v to the 12v line on the system and the power input pin on the PSone screen.

I hope this clears things up.

Post by **gannon** » Fri Dec 09, 2005 7:25 pm

I think he's talking about using a higher supply voltage for the dc-dc converters and using the 7808 to regulate it before the lcd for the few components before the 7805s

cennar · Post by **cennar** » Sat Dec 10, 2005 3:08 am

well im going to have to get the 9.2 rc car battry and charger next pay day, thats if 7.2 wont cut it quite right. oh and how many amps is going to turn it on again?

sbf · Post by **sbf** » Sat Dec 10, 2005 4:29 am

I think he's talking about using a higher supply voltage for the dc-dc converters and using the 7808 to regulate it before the lcd for the few components before the 7805s

Thats exactly it!!!!!

I just didnt want to use higher than 7.2v, therefore not requiring the 7808 for the lcd, but the dc dc convertor (for the 3.3v) wants 10V !

nos_slived · Post by **nos_slived** » Sun Dec 11, 2005 1:54 am

Actually, they say 9V minimum, but multiple people have confirmed that they used it at 7.2V. It is probably less efficient at the lower voltages though.

sbf · Post by **sbf** » Sun Dec 11, 2005 10:56 am

I've settled for a 12v power source consisting of 10 AAs, the psone lcd will now become friends with a 7808!

Now all I need is some sort of charging circuit for the AA's, preferably one that lets me play while charging, and carries on charging when I turn off the N64.

Any ideas on this?

sniper_spike · Post by **sniper_spike** » Sun Dec 11, 2005 11:56 am

Perhaps one of these?
http://www.radioshack.com/product/index ... age=search

And daguuy's diagram(s) for it: