Closed seanch80 closed 2 years ago
Yes, you are right, the voltage could be a bit at the limit. I have seen from the tests that it works ,but to improve it without modifying the scheme, just replace the 1n4148 diode with a Schottky one such as BAT43 or similar. It is also possible to remove the diode and put a jumper, this was left over from the old version where I supplied the 12V externally.
Thanks for the explanation. I think I will use a jumper instead of the diode then.
..with the diode replaced by a jumper. 😄
good job! I post the file on Github with thanks. I also added the stl for print the handle to glue all the jumpers and move them more easily between the high and low position. 👍
Very nice. Thanks for sharing this project on github. It was fun to build and works great!
Hello. Taking the 5V (more realistically 4.7V if powered via USB) from the Arduino +5V pin and routing it through the diode only gives about ~4V into the 7660S, giving a resulting negative voltage of about -4V. According to the datasheet of a randomly chosen 4116 DRAM chip, the min/max acceptable values for the -5V line is -4.5V to -5.5V.
How does that work? Are typical 4116 DRAM chips not so picky when it comes to the -5V line?
Also, I wonder why the 1N4148 diode was chosen, and not a schottky diode or other with less voltage drop?