Is it ok to do this without filtering or smoothing the current assuming amperage and voltage rating are close? I thought I read that unregulated power supplies produce sloppy current whereas batteries obviously supply very smooth consistent current.
I want to power a mini video game console cpu board this way and the board was designed to work solely with batteries. I tried it and it works, but the video output from the board is poor quality and sorta blurry when I use the wall wart to power it. I assume it is because the supply of power is not smoothed out.
So, should I, can I, somehow make a simple line filter with a capacitor or something to tidy up the current to the cpu, or does this require a regulated power supply?
On a side note, the portable tv I'm using for the project comes with an unregulated ac/dc converter and can be used with that or batteries, so does this mean the tv has internal, built-in filtering?
If you are using the barrel jack, there is a voltage regulator and some caps between the jack the microcontroller. Those will take care of smoothing and filtering.
Yes, your tv also most likely has some voltage regulation.
There is no barrel jack, it was designed to only work with 3xAAA batteries. So bottom line is I should find a tiny 4.5v regulated power supply, and there is no real good way to do it with a cheapo unregulated supply, right?
So no Arduinos at all? This is really a "General Electronics" question.
Yes you can put a regulator onto an unregulated supply. A 3-terminal regulator like a 7805 will do all the work for you, but it will need a few capacitors and maybe a diode added. There must be a bazillion circuits published that you can copy. Or maybe search for "Battery eliminator"?
Techincally this isn't an Adruino question but for this project I did incorporate an Uno and this is the first forum that popped into my head when I came accross the issue.
For what it's worth I built a mini bar/desktop arcade machine. I used a portable 7-inch LCD tv custom-fit into a mini arcade cabinet (inititially designed to fit an i-pad/tablet) and used the video game cpu (mentioned above) for the logic. The cpu board was out of one of those plug-and-play console joysticks that have RCA outputs that plug into a tv. The joystick just turns on and a menu comes up with 12 classic video games. I gutted the joystick and incorporated the whole mix into a mini arcade cabinet for a bartop video game.
I used the adruinio and a relay board to do tasks such as turn the tv on when the unit is powered up, disable the cpu's auto-shutoff during idle (which is supposed to normally conserve battery power), checking for idle activity and randomly switching back to the menu and starting a random game while in 'attract mode', and providing an option for muting (and/or partially muting) sound during attract mode.
I wanted the whole unit to have one A/C power cord and everything else from that powered by ac/dc converters and usb chargers internally.
It works absolutely perfect except the output to the screen is scratchy and I'm guessing it's because of the filtering issue I asked about in the above posts.
Anyways, thank you for the advice. It is appreciated!
I found a L7806 Step Down 8V-35V to 6V converter on eBay for a few bucks. I think this should do the trick. I'll post results for anyone interested when I get it installed.
Thanks!
PS: Correction: the cpu board takes FOUR AA batteries (6V).
