happyrat1
Destroyer of Eardrums!!!
The LED display alone will draw way more than 20 milliamps.
You've got everything you need to know how to wire it up now.
Gary
You've got everything you need to know how to wire it up now.
Gary
HELP I got an old Accordion with Midi interface
- Thread starter blaze_01
- Start date
happyrat1
Destroyer of Eardrums!!!
That will probably blow up the lithium battery.
VERY BAD IDEA@!@!@!
NEVER PLUG VOLTAGE SOURCES IN PARALLEL!!!!!!!!
DO NOT DO IT!!!!!!
VERY BAD IDEA@!@!@!
NEVER PLUG VOLTAGE SOURCES IN PARALLEL!!!!!!!!
DO NOT DO IT!!!!!!
happyrat1
Destroyer of Eardrums!!!
DO A HALF ASSED JOB AND YOU WILL DESTROY YOUR EQUIPMENT.
THERE ARE NO SHORTCUTS TO HARDWARE HACKING!!!!!!!!
THERE ARE NO SHORTCUTS TO HARDWARE HACKING!!!!!!!!
happyrat1
Destroyer of Eardrums!!!
NEVER CONNECT BATTERIES IN PARALLEL.
SLIGHT DIFFERENCES IN VOLTAGE AND IMPEDANCE WILL CAUSE ONE TO FEED BACK AND DRAIN INTO THE OTHER CAUSING AN EXPLOSIVE CHEMICAL REACTION.
NEVER! NEVER! NEVER!!!!!!!!!
Gary
SLIGHT DIFFERENCES IN VOLTAGE AND IMPEDANCE WILL CAUSE ONE TO FEED BACK AND DRAIN INTO THE OTHER CAUSING AN EXPLOSIVE CHEMICAL REACTION.
NEVER! NEVER! NEVER!!!!!!!!!
Gary
happyrat1
Destroyer of Eardrums!!!
You have to disonnect the VCC+ 5 VDC from the MIDI side of the interface. If you cut power to the interface bad things will happen.
Gary
Gary
Whaat. Thats not what i learned. I have tons of devices with batteries in parallel hehe.
And even some flashlights, and the headlight i got right now on my head got two liion batteries in parallel. Sometimes they drain a bit uneven. Never had any explosions though.
And even some flashlights, and the headlight i got right now on my head got two liion batteries in parallel. Sometimes they drain a bit uneven. Never had any explosions though.
Ouch.. i just wanted this fired up today.You have to disonnect the VCC+ 5 VDC from the MIDI side of the interface. If you cut power to the interface bad things will happen.
Gary
Maybe i just do it the first way you suggested, instead of modding the cable, i mod inside the instrument and just drill a hole for the power cable. Gotta take a closer look at the drawings.
Did i need a specific type of resistance? Any regular resistance of noted ohm will work? If so i might smash something useless and loot it.
happyrat1
Destroyer of Eardrums!!!
I'm not 100% certain the resistance is needed but it is MIDI spec and should be required to protect the circuitry.
Any 220 Ohm resistor will do as long as it's rated 1/2 watt or better. I wouldn't risk anything smaller or again, magic smoke may be released.
Gary
happyrat1
Destroyer of Eardrums!!!
Actually I just realized the resistor is not necessary and may actually be detrimental.
It would have to dissipate I^2 * R wattage which is a ridiculous amount of power.
Leave the resistor out.
Gary
It would have to dissipate I^2 * R wattage which is a ridiculous amount of power.
Leave the resistor out.
Gary
Alright. Then im pretty certain i could get this done soon without ordering any parts.
But i want to do it like this:
Inside the accordion behind the midi input,
I cut the yellow wire (5) so that the usb doesnt power it anymore.
I then use that yellow wire which now is cut off the midi port put a resistor as you noted, at the end of it.
Then i use a dc adapter rated to 5v to the yellow wire.
The ground from the adapter straight into the ground of the accordion.
Or would that cause grounding issues?
I was thinking of just buying an adjustable dc adapter tomorrow and a input port.
And get the port fitted to the instrument, and wired as i said above.
This would go like a hand in glove?
But i want to do it like this:
Inside the accordion behind the midi input,
I cut the yellow wire (5) so that the usb doesnt power it anymore.
I then use that yellow wire which now is cut off the midi port put a resistor as you noted, at the end of it.
Then i use a dc adapter rated to 5v to the yellow wire.
The ground from the adapter straight into the ground of the accordion.
Or would that cause grounding issues?
I was thinking of just buying an adjustable dc adapter tomorrow and a input port.
And get the port fitted to the instrument, and wired as i said above.
This would go like a hand in glove?
Good news. But i preffer to be safe if needed.Actually I just realized the resistor is not necessary and may actually be detrimental.
It would have to dissipate I^2 * R wattage which is a ridiculous amount of power.
Leave the resistor out.
Gary
Aaaaaaa i feel so close now to get this working!
If it doesnt work after this, i rip all the electronics out and play the instrument with its original italian reed plates from the 60's haha
happyrat1
Destroyer of Eardrums!!!
Here's how I'd do it.
1) Clip the yellow wire and extend it to a 3.5 mm phone jack. Run a wire from ground to the sleeve of the jack.
2) drill the case and install the jack.
3) Plug in a 5 V REGULATED DC Adapter with a standard 3.5 mm plug output.
4) If noise is a problem be prepared to replace the adapter's cable with a shielded wire instead of a stranded pair.
5) Either that or else add a noise rejecting filter circuit to the internals of the jack. Easier to shield the cable though.
Gary
1) Clip the yellow wire and extend it to a 3.5 mm phone jack. Run a wire from ground to the sleeve of the jack.
2) drill the case and install the jack.
3) Plug in a 5 V REGULATED DC Adapter with a standard 3.5 mm plug output.
4) If noise is a problem be prepared to replace the adapter's cable with a shielded wire instead of a stranded pair.
5) Either that or else add a noise rejecting filter circuit to the internals of the jack. Easier to shield the cable though.
Gary
happyrat1
Destroyer of Eardrums!!!
Remember. Digital logic requires REGULATED power. I'd say 5V DC at 1 Amp should be more than enough.
Don't use a cheap variable supply that isn't regulated.
Gary
Don't use a cheap variable supply that isn't regulated.
Gary
Ok thanks. Now i need to rip apart a headset.
So if the power and ground comes from an external supply like this, does that mean i could cut pin2 too? The shield?
Is ONLY pin5 needed to provide all data needed to the computer?
Im just asking to know the actual usb cable will still be able to function after i added an external source of power.
If i gonna test this with batteries first just to be sure, my options would be:
3x aa 1.5v =4.5v
Or
4x aa 1.5v =6v
I guess 6v would be a bit unsafe.
So if the power and ground comes from an external supply like this, does that mean i could cut pin2 too? The shield?
Is ONLY pin5 needed to provide all data needed to the computer?
Im just asking to know the actual usb cable will still be able to function after i added an external source of power.
If i gonna test this with batteries first just to be sure, my options would be:
3x aa 1.5v =4.5v
Or
4x aa 1.5v =6v
I guess 6v would be a bit unsafe.
Thats why i wanna test with batteries first cause i got nothing like that lying around at the moment.Remember. Digital logic requires REGULATED power. I'd say 5V DC at 1 Amp should be more than enough.
Don't use a cheap variable supply that isn't regulated.
Gary
What in the world uses 5v that i could use xD haha.
Well my computer got a 5v and a 12v from its power supply. Hmmmm
happyrat1
Destroyer of Eardrums!!!
DATA signal WILL NOT WORK without a reference ground.
The ONLY wire you cut is the yellow one and piggy back the power supply ground onto the signal ground.
Nothing else would work.
Gary
The ONLY wire you cut is the yellow one and piggy back the power supply ground onto the signal ground.
Nothing else would work.
Gary
happyrat1
Destroyer of Eardrums!!!
Any USB charging unit or Wall Wart can deliver +5V DC at 1 or 2 amps depending on the model. They are switching supplies and pretty well regulated.
The only thing you need is a USB A to coaxial plug and you'd have a well shielded, regulated, power supply.
You'd also require a suitable coaxial jack for the accordion.
They do sell those cables from suppliers in China but I'm not sure where you'd buy one locally.
Don't even try to hack a regular USB cable though. Those things use like 3 strands of 80 guage wire per cable. Impossible to solder reliably.
Gary
The only thing you need is a USB A to coaxial plug and you'd have a well shielded, regulated, power supply.
You'd also require a suitable coaxial jack for the accordion.
They do sell those cables from suppliers in China but I'm not sure where you'd buy one locally.
Don't even try to hack a regular USB cable though. Those things use like 3 strands of 80 guage wire per cable. Impossible to solder reliably.
Gary