MiSTer FPGA Forum

Hello guys!

I have got a special question for the technician between you.

I just assembled jammix from Ricardo and switched it on. I made sure that i use a strong power supply and measured

nearly 5V from the power supply terminals. When the unit is connected and switched on I measure around 4.8 V at

the terminals of the jammix edge connector (between ground and 5V) - so this is the voltage under load.

My question is - should I turn the voltage on the power supply higher so that I measure around 5V at the edge connector

or is it ok this way? In other words - what is the correct value here - is it the voltage directly coming from the power

supply (which is correct) - or should the operating voltage (measured at the edge connector) be the 5V

regards,

4.8 is common for a 5 volt supply and is well within range of the (poor) tolerance spec for most supplys. Different components in power supplys and all other electronic stuff differ a bit due to normal variations. Under load the voltage drops more the closer you are to the power supply limits.

The mister should work just fine with 4.8 as would most other stuff that runs on 5 volt. It wont explode or anything

Lex wrote: ↑Thu Jul 20, 2023 9:25 pm

Hello guys!

I have got a special question for the technician between you.

I just assembled jammix from Ricardo and switched it on. I made sure that i use a strong power supply and measured

nearly 5V from the power supply terminals. When the unit is connected and switched on I measure around 4.8 V at

the terminals of the jammix edge connector (between ground and 5V) - so this is the voltage under load.

My question is - should I turn the voltage on the power supply higher so that I measure around 5V at the edge connector

or is it ok this way? In other words - what is the correct value here - is it the voltage directly coming from the power

supply (which is correct) - or should the operating voltage (measured at the edge connector) be the 5V

regards,

Thank you once more for your order.
If you are using it in a Classic Arcade with JAMMA Edge and an original Arcade PSU, yes you can adjust the pot for a perfect 5V. But 4.8v seems ok. JAMMIX also have fuses that shut down if you go higher or lower than expected.

If you plan to use it in a mini ITX case I strongly suggest you use a PicoPSU. It will gives you a perfect 5v independently the quantity of USB adding, HDD etc you plug.

Kind regards
Ricardo

thx guys for your answers