battery snap with three wires

[rousejeremy]

Apparently it was pulled from a Spector Bass. WTF!?!?!

[John Lyons]

0v
9v
4.5v ?

[Ice-9]

subterfuge

[Rob Strand]

WTF!?!?!

WTF indeed!

Do some measurements.

With the bass powered up, measure voltages on all wires.

With the bass powered down, measure the resistance between the blue and the other terminals?
Check for diodes in each direction as well.

If you can trace where the wires go on the board/control cavity.

Maybe you can build-up enough info to work it out.

Does the battery snap have any metal on the top?

[Slowpoke101]

The third wire (blue ) is most likely for strain relief. It would be shorter than the red and black so that if you drop the battery when changing it out the blue wire would stop the other wires from being pulled out of the battery snap or off the pre-amp board.

[EBK]

The third wire (blue ) is most likely for strain relief. It would be shorter than the red and black so that if you drop the battery when changing it out the blue wire would stop the other wires from being pulled out of the battery snap or off the pre-amp board.

So, almost like a butfor then?

I've got nothing.  Why blue?  That's the question that I want the answer to.

[willienillie]

Why blue?

It was white originally, but turned blue from all the strain.

[Rob Strand]

Funny thing is a quick poke around for pics of Spector control cavities doesn't show any such battery snaps.

What era bass is it?

[iainpunk]

The third wire (blue ) is most likely for strain relief. It would be shorter than the red and black so that if you drop the battery when changing it out the blue wire would stop the other wires from being pulled out of the battery snap or off the pre-amp board.

there are battery snaps with nylon wires that have a tie wrap like system, where you can shorten it to the desired length. i prefer epoxy to the case tho, if i put a snap in a pedal that is, most of em i build with power jacks only

[Ice-9]

The battery snap has a clip on back piece which should just clip off, unclip the back and have a look where the blue wire goes.

[amptramp]

Maybe it's for a battery with ground, 9 volt and 4.5 volt outputs.  For a lot of what we do, a 4.5 V and 9V battery would solve a lot of problems.  The maddening part is that there are six cells in a 9 volt battery and if we could just bring out a tap at the middle connection, a lot of designs could get simpler.  Maybe someone should start a thread on how to butcher surgically enhance a battery for our typical uses.

[Phend]

Blue wire connects to a diode which connects to ground to protect the circuit, in case of "touching" the battery backwards? Just a guess.

[EBK]

I honestly believe the blue wire is just there for a laugh, perhaps as a mild form of nerd sniping.



Here is one I made in about two minutes:

[Phend]

Looks "to code" to me

[Rob Strand]

I think Slowpoke got it.

[aron]

Wow. Apparently first class! That would have saved so many problems in the past.

[Ice-9]

Maybe it's for a battery with ground, 9 volt and 4.5 volt outputs.  For a lot of what we do, a 4.5 V and 9V battery would solve a lot of problems.  The maddening part is that there are six cells in a 9 volt battery and if we could just bring out a tap at the middle connection, a lot of designs could get simpler.  Maybe someone should start a thread on how to butcher surgically enhance a battery for our typical uses.

Yeah but that's not gonna work when pedals are powered by both battery and psu.

[Ice-9]

So it is just a strain relief then. canny good idea that man.

[anotherjim]

I broke open a 9v PP3 once - and counted 7 cells. That explained over 10v reading when new. I figure it was to overcome internal resistance which would prevent 6 cells making 9v on load. Smaller cells = less capacity of course. Probably was a zinc-carbon type.

[antonis]

That's absolutely true, Jim..

On the contrary, rechargeable 9V batteries consist of only 6 cells, resulting into marginally +9V when fully charged..