AC vs DC

Champion (285)

27-11-2020, 02:30

Hi dears
I'm from Yemen and because of war most people do not have electricity. Instead we are using solar energy which is mostly a DC 12 volts. In my home I have a cheap Chinese flat TV and a digital satellite receiver which operate normally on 12 volts DC. Unfortunately, I cannot enjoy my AX230 Sakhr computer 'cos it needs electricity (220 volts AC). Can you instruct me on how I can get it to operate by using the12 DC solar energy? I mean it might need some sort of soldering (some available electronic parts) to feed it with the proper needed energy (keeping in mind to protect the computer's internal parts from getting burned or becoming mulfunctioning 'cos I certainly do not want to ruin my precious MSX and lose it, and I'd rather keep it alive without using it for eternity than losing it forever).

Note: Finding the needed electronic components is hard in here. So I would look for them/and then get them from other mulfunctioning electronics devices (radios, old TV sets, DC converters, etc).

By NYYRIKKI

Enlighted (6088)

27-11-2020, 05:22

I'm not familiar with Sakhr-computers, but generally this new MSX computers internally use just +5V DC, +12V DC and -12V DC. You can pretty safely leave the -12V DC disconnected unless you want to use something like RS-232 cartridge with the machine. Finding a PSU that provides you few amps of +5V DC should not be hard even if you have access only to recycled electronics. If you are unsure what voltage is what, you can test the continuity against last pins of cartridge slot. (Pinout here)

Good luck!

By gdx

Enlighted (6421)

27-11-2020, 08:12

Maybe you can use a device like this:

https://www.ebay.com/itm/150W-Car-Power-Inverter-12V-to-220V...

If your solar panel is quite powerful, you could power an MSX with one or two extensions and a flat screen with it.

By mcolom

Champion (320)

27-11-2020, 08:54

To me, the largest problem is getting enough power from the solar panel for both the msx and the screen.

By Pencioner

Scribe (1608)

27-11-2020, 10:17

In Yemen, sun is giving quite more energy per panel's square meter i guess... maybe even few times more in average than in European countries

By st1mpy

Paladin (945)

27-11-2020, 10:25

It may not work on all machines but something like This ?

By Xan0ri

Master (181)

27-11-2020, 11:16

I can at least confirm converting to 12volts is possible and quite easy too. Not too advanced stuff. I just recently did the same modification (external power source feeds +12v, +5v, gnd, and -12v) to the mainboard power socket of VG8235. Only thing needed was the circuit diagram of mainboard, and colour codes for the attached wires. From that on, things are pretty self explainable. And if not counting the wires, no extra components were needed.

By gdx

Enlighted (6421)

28-11-2020, 01:37

Another thread about the adapter ATX power supply to MSX cartridge port:
https://www.msx.org/forum/msx-talk/hardware/cartridges-that-...

I think you can power in 5V only (2.5~3A). Only some cartridges will not work (The FM Pac and a few sound cartridges). You just have to find the 5V input in the MSX. The +12V is almost useless without the -12V.

By Nprod

Expert (105)

30-11-2020, 15:15

I'm with GDX on this - try to find an inverter. It's a useful device to have in general, not just for MSX stuff. Alternatively you can look for an old UPS unit with a dead battery, they're not hard to find. Not only is the inverter built-in, but you can also hook them up to a large car battery, so you can have 220VAC at night or whenever electricity is not available.

By st1mpy

Paladin (945)

30-11-2020, 15:46

An inverter wastes energy?

By Nprod

Expert (105)

30-11-2020, 15:54

st1mpy wrote:

An inverter wastes energy?

Yes, but it's better than wasting your MSX with makeshift power supply mods...