5" screens and some questions about powering them on a n64 board

Joined
Aug 10, 2017
Messages
8
Likes
6
Hey guys, I'm looking around for 5" composite input screens for my n64 portable. Preferably off amazon because prime shipping.

Some I've come up with are:
https://www.amazon.com/gp/product/B00CZ85YVU/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
https://www.amazon.com/800x480-Fold...01GFFMRY0/ref=cm_cr_arp_d_product_top?ie=UTF8

I notice that all of these small screens say they need 12 volts. Can they decently run off 7.4 volts as well? I also read somewhere on here that there are regulators inside that step the 12v down to 5v. Anyone know of what points I can solder to on the N64 board to get 5 volts to connect the screen to?
 
Joined
Apr 27, 2018
Messages
160
Likes
68
Location
Kentucky
Portables
Wii Laptop V2.0, GameCube SPITE
Hey guys, I'm looking around for 5" composite input screens for my n64 portable. Preferably off amazon because prime shipping.

Some I've come up with are:
https://www.amazon.com/gp/product/B00CZ85YVU/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
https://www.amazon.com/800x480-Fold...01GFFMRY0/ref=cm_cr_arp_d_product_top?ie=UTF8

I notice that all of these small screens say they need 12 volts. Can they decently run off 7.4 volts as well? I also read somewhere on here that there are regulators inside that step the 12v down to 5v. Anyone know of what points I can solder to on the N64 board to get 5 volts to connect the screen to?
I'm not too knowledgeable about the n64, but I looked up a pinout and didn't see a 5v supply on it. You can build a custom regulator or voltage divider circuit that should work fine for that. You just have to have to run a circuit in parallel with the 7.4V feed on the board and use resistors to split the voltage from 7.4V to 5V. Based on my limited knowledge of electronics, I believe that should work.

Someone here can correct me if I'm wrong (and I might be). That being said, if the board on the lcd has a regulator to step down the voltage from 12V to 5V, it might work off 7.4V since it's still more than the 5V the lcd needs to run. The 12V is probably a limit (no more than 12V) rather than a requirement.

I would go ahead and get one and try it first off 7.4V and see if it works before doing anything crazy.
 

Gman

RTFDS
Staff member
.
.
.
.
.
Joined
Feb 25, 2016
Messages
1,435
Likes
2,873
I'm not too knowledgeable about the n64, but I looked up a pinout and didn't see a 5v supply on it. You can build a custom regulator or voltage divider circuit that should work fine for that. You just have to have to run a circuit in parallel with the 7.4V feed on the board and use resistors to split the voltage from 7.4V to 5V. Based on my limited knowledge of electronics, I believe that should work.

I would go ahead and get one and try it first off 7.4V and see if it works before doing anything crazy.
A voltage divider won't work for a voltage supply because the output will affect the voltage, known as the "loading effect". I would try the screen from 7.4v, that is correct.
 

Shank

Moderator
Staff member
.
.
Joined
Jan 31, 2016
Messages
1,286
Likes
2,723
Portables
6
...voltage divider circuit that should work fine for that. You just have to have to run a circuit in parallel with the 7.4V feed on the board and use resistors to split the voltage from 7.4V to 5V. Based on my limited knowledge of electronics, I believe that should work.
N O P E
I second what Gman says. Don't do this. Voltage dividers are for setting reference voltages, and should not be used on anything that has a load on it.
 
Joined
Apr 27, 2018
Messages
160
Likes
68
Location
Kentucky
Portables
Wii Laptop V2.0, GameCube SPITE
N O P E
I second what Gman says. Don't do this. Voltage dividers are for setting reference voltages, and should not be used on anything that has a load on it.
Okay, thanks for the correction!
 

Trozze

.
Joined
Jun 25, 2018
Messages
15
Likes
16
Location
Sweden
All screens I have used has accepted 7.4 volt with no issues. The switching IC can usually go as low as 6volt.
 
Last edited:
Top