piggyback 5volts from dreamcast karaoke unit's power?

Started by macabre, October 28, 2010, 06:52:49 AM

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macabre

This is a completely different project from that other thread, it just so happens that both trinkets I'm building require 5 volts.

What this project deals with involves the dreamcast karaoke attachment that I have. I got an old yellow'ed plastic one, and am using the shell to house adapters for the dreamcast, one which requires 5 volts from a wall socket.

Here are pictures of what I'm working with;

The bottom of the karaoke unit showing the power info

The inside of the karaoke unit, I know I'll need to keep the yellow board (power) as it also reroutes power to the dreamcast itself (a single power plug is inserted into the karaoke unit, and the top of the shell has a plug that sticks into the open socket right to the left of the yellow tape). Everything else in the unit is going to be removed.

This is the plug that goes with the adapter I want to build inside the unit.. I know I'll have to keep the small board behind the plug, but the Red / Black power wires going to the plug itself is what I'm assuming I'll have to be attaching to the karaoke's power board somewhere.


Inside the karaoke unit, from its power board to its main board, is that 4 black wire connection thing. I'm assuming that two of those are the sort of wires that are like the ones I'm needing to solder, maybe a third is a ground or something.

I really don't want to randomly start connecting and testing wires.

Is there any way I can go about testing for voltage? I saw a voltmeter at walmart, but it was listed as ranging / detection of 6 to 12 volts.


If this fails, then I'll probably just scrap the idea of saving the original dreamcast power cord and build in a small multi-outlet tap, and have a standard power socket on the outside of the unit (unfavored as it would be far less attractive).


Thanks in advance for any help guys!

l_oliveira

What you need is not tamper with your unit and use an Y "figure 8" (this is what internet/google said about the kind of connector the Dreamcast uses for power) power cord to power on both units while using an single connector.

macabre

I might not have described what I had intended to do as elegantly as I should have~

I have no use for anything inside the karaoke attachment (pictured). I was going to put in different hardware and adapters, one of which requires a power source (5 volts).

The power board pictured is from the karaoke unit, it has its own built in splitter (when set up as intended, the single figure8 power cable plugs into the karaoke unit, and it has its own figure8 power cable that goes from the pictured power board to the dreamcast).

When looking back at this (ignoring all the green boards), I had just assumed that 1.) I would keep the power board, because 2.) somewhere on that board I could attach the black/red wires from the plug from what I want to add.

I might be misunderstanding your suggestion.

l_oliveira

Then you might as well indeed use the existing power supply on the Karaoke unit for the purpose of supplying the 5V your project require. If it supplies more than 5v (please measure it) you can simply use an 7805 voltage regulator to drop the voltage.

bigsanta

#4
potential divider ? I don't know what is trying to be done here though?