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Doubts while making a voltage line inducer for DreamPi

Posted: Sat Jul 24, 2021 3:30 am
by VladTepesDraculea
Hi everyone,

I wasn't sure if I should make a new thread or not, so sorry if I shouldn't have.

Either way, I just soldered my voltage line inducer for DreamPi. I followed this thread and thested everything with my multimeter but some doubts occur to me that made me fear to test it out and fry anything:

In a phone line the cables are reversed, the green and red lines switch from end to end of the cable. So I started with one end having the red cable on the second position and it ends on the third one. I've also noticed that some cables meant only for data aren't reversed. Should I unreverse mine in the circuit or leave them be?

Is the inducer is unidirectional? If so, the left side of the scheme should be connected to the Dreamcast or to the USB modem?

Finally, the USB modems I fine only seem to use the green and red line, is it sufficient?

Thank you.

Re: Doubts while making a voltage line inducer for DreamPi

Posted: Sun Jul 25, 2021 4:02 am
by VladTepesDraculea
VladTepesDraculea wrote:Hi everyone,

I wasn't sure if I should make a new thread or not, so sorry if I shouldn't have.

Either way, I just soldered my voltage line inducer for DreamPi. I followed this thread and thested everything with my multimeter but some doubts occur to me that made me fear to test it out and fry anything:

In a phone line the cables are reversed, the green and red lines switch from end to end of the cable. So I started with one end having the red cable on the second position and it ends on the third one. I've also noticed that some cables meant only for data aren't reversed. Should I unreverse mine in the circuit or leave them be?

Is the inducer is unidirectional? If so, the left side of the scheme should be connected to the Dreamcast or to the USB modem?

Finally, the USB modems I fine only seem to use the green and red line, is it sufficient?

Thank you.
This is my interpretation, if anyone can check / correct it.

Image

Re: Doubts while making a voltage line inducer for DreamPi

Posted: Sun Jul 25, 2021 2:58 pm
by megavolt85
VladTepesDraculea wrote:If so, the left side of the scheme should be connected to the Dreamcast or to the USB modem?
irrelevant
all modems have a diode bridge at the input, polarity does not matter

Re: Doubts while making a voltage line inducer for DreamPi

Posted: Sun Aug 01, 2021 12:01 pm
by XVO
If you've the Japanese or US version you can pull 12volts from the Dreamcast itself and use a potmeter to reduce it to 9volts so you don't have to worry about the battery anymore.

I did it on my NTSC-J DC three years ago and he's still going strong