Chassis Connection

[trem]

Sorry if this is a stupid, self-evident question. I just have a very basic knowledge of electronics.
Would it be a bad idea if the Positive side of the B+ were connected to the chassis instead of the Negative.?

I was actually thinking about car batteries at first.
Was it just by chance that the Neg side was connected to the car chassis instead of the Pos side.?
Thank You

Again, sorry if this is a idiotic question.....

[g1]

It would be a bad idea only in that people wouldn't be expecting it anymore, so a careless tech might get bit.
But there was a time when you would see positive ground equipment, like old stereo consoles with PNP devices.

As to the history of why cars changed over from positive to negative ground, I'm not sure. May have to do with going from generators to alternators but that's just a wild guess.

[x-pro]

All vacuum lamps are electronic. They're not positronic!
Their control is tied to the cathode.
There are many amplifiers with stage-by-stage connection of the anode voltage, i.e. it drops in level from the power supply to the input parts of the circuit.
Are you suggesting B+ to ground? And then how to organize this lowering of power supply? If it is done through the cathode supply line, some undesirable feedback element will be introduced into each subsequent controlled stage.
With transistors, this is acceptable.

[Helmholtz]

In short: It's possible, but not with existing designs.

[g1]

In short: It's possible, but not with existing designs.

Do you mean for vacuum tubes only, or electronics in general? As stated above, there is existing (old) equipment that uses negative supply. The first post mentioned automotive, it was only xpro that mentioned tubes.

[Helmholtz]

Do you mean for vacuum tubes only, or electronics in general? As stated above, there is existing (old) equipment that uses negative supply. The first post mentioned automotive, it was only xpro that mentioned tubes.

As said, it's possible with a suitable design (regardless of SS or tube).
E.g. most amps use several B+ levels. This would have to be redesigned for different B- levels.
There might even be existing designs which work the same regardless which side of the supply is grounded.

[g1]

I took this to be about only the general concept, not any specific examples. Ground is relative. We can have positive supply (negative ground), or negative supply (positive ground). Either way, ground can connect to chassis.
It is good for anyone to understand that ground is relative.

[trem]

It would be a bad idea only in that people wouldn't be expecting it anymore, so a careless tech might get bit.
But there was a time when you would see positive ground equipment, like old stereo consoles with PNP devices.

As to the history of why cars changed over from positive to negative ground, I'm not sure. May have to do with going from generators to alternators but that's just a wild guess.

Thanks for all the replies.