Power Questions about FC Twin (56ker's beware!)

Billybb347 · Post by **Billybb347** » Thu Mar 15, 2007 10:02 am

I recently bought the FC Twin for use in my portable. I have opened it up and attached a wire to each of the positive and negitive leads (I hope I got it right) on the power plug to test if the battery I was going to use (either a 9.6V 700maH R/C battery or a 7.2V FP-330 Sony InfoLithium) would work.

When I attached the battery (just fully charged) to the other end, and turned it on, nothing happened.
I tested the battery with the mulitmeter and the needle didn't move.
(By the way what do the markings on an anolog mulimeter mean?)
I did the same on different batteries of similar charges and Voltage, and got the same result.
What kind of battery do I need to run this machine?

jeroen · Post by **jeroen** » Thu Mar 15, 2007 10:05 am

700 mah isn't really a lot. is that 7.2 battery a camecorder battery?

Billybb347 · Post by **Billybb347** » Thu Mar 15, 2007 10:10 am

Yes it is. Its a 7.2V 5.0W Li-ion Fp-330 from a camcorder, the 700maH was a last resort battery with a higher charge.

jeroen · Post by **jeroen** » Thu Mar 15, 2007 10:11 am

ah. well 700 isnt nearly enough. At least I think so. Might power it for a little. the camcorder battery how much mah is it?

ATOMICMAN · Post by **ATOMICMAN** » Thu Mar 15, 2007 11:14 am

i got mine running off a 7.2v 2000mah nicad rc battery (that also had the screen going too). ran like a champ off it.

grahf · Post by **grahf** » Thu Mar 15, 2007 11:23 am

Try using the back pin for ground. I seem to recall the side pin isnt connected.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Thu Mar 15, 2007 3:25 pm

grahf wrote:Try using the back pin for ground. I seem to recall the side pin isnt connected.

so thats what it was

i got pretty frustrated one day with my fc twin because of power issues, it was doing some other freaky things also though

Billybb347 · Post by **Billybb347** » Thu Mar 15, 2007 5:05 pm

Would either of these work?
http://www.radioshack.com/product/index ... age=family

http://www.radioshack.com/product/index ... age=family

Does the board need 10V and 800maH like the wall adapter says?

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Thu Mar 15, 2007 5:07 pm

yeah but the first one is better

shmagoogin77 · Post by **shmagoogin77** » Thu Mar 15, 2007 7:08 pm

definitely

Billybb347 · Post by **Billybb347** » Thu Mar 15, 2007 8:14 pm

Turbo Tax 1.0 wrote:yeah but the first one is better

7.2V is enough to run the FC Twin?

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Thu Mar 15, 2007 8:20 pm

7.2 volts will not power the actual fc twin. it will go into the 7805 regulator and be bumped down to 5volts; which will power the fctwin

Billybb347 · Post by **Billybb347** » Thu Mar 15, 2007 8:27 pm

Turbo Tax 1.0 wrote:7.2 volts will not power the actual fc twin. it will go into the 7805 regulator and be bumped down to 5volts; which will power the fctwin

So could I just take off the power board completely, and keep the transistor,( and NES board because i dont think ill use it)? or does is there more to it than just the one transistor translating the power from 7.2 to 5 volts?

grahf · Post by **grahf** » Thu Mar 15, 2007 9:48 pm

You can remove the NES board if you like. You can pull rgb and audio directly off of the SNES board (with the help of some caps and resistors), but it is not 100% usable. I chose to keep my power board, and use the video encoder as an RGB clamp (I pulled RGB from the cxa1645 output pins). If you plan on using composite to hook up your video, you need to keep the cxa1645 anyway. I use the DE-SW050: http://www.dimensionengineering.com/DE-SW0XX.htm instead of 7805s on all my projects since they dont require a heatsink, and grant you much better battery life. A bonus is that they seem to keep a stable 5v output almost down to 6v input.

I have found the FC Twin to draw very little power, well under 200mAh. I didnt measure it alone, but my rgb modded PSOne lcd and fctwin together only draw about 550mAh(!)

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Thu Mar 15, 2007 10:01 pm

grahf, how long does it usually take for those regulators to get to your doorstep?
i ordered one but its taking awhile

i'm probably just impatient though