floating point power supply

Can you give us a context?

Low voltage DC? Mains? High Voltage?

Could floating point power supply be another term for isolated DC power supply? If so the feature is that any single point in the circuit may be brought to a specific potential without causing current to flow outside the original circuit.

I have experienced a situation where cheap temperature transmitters would not function properly when the 4-20 mA loop supply - was grounded due to current flow thru the grounded junction thermocouples. Isolating (or floating) the 24 VDC loop supply allowed the system to be grounded at the primary temperature elements and function more accurately than before.

The feature could also help to prevent control system power interruption caused by a technician accidentaly grounding a field wire.

I understand a floating power supply to mean the Negative is not grounded to earth (or the chassis) This is useful in situations were one has two or more sources of power and wishes to keep the Neutral of each supply isolated from each other.

It can cause problems in situations where the floating device is the only power supply and the Neutral potential can riser above Earth. This will give false triggers to circuits and if allowed to rise too far the potential (literally) to give an operator a shock.

In my applications floating devices are either fully isolated or tied down to earth [if allowed] to stop them floating.

In addition to what I said above;

This means a floating point power supply with a +ve output of say 5V dc would have a positive with 5V potential above its -ve, but as this is not tied to earth the -ve could have a potential of say 10V above earth. Therefor the +ve [5V] would have a potential of 15V above ground / Earth.

Useful in certain situations.

Guest, congratulations!!!

You have won the award for the most difficult to understand answer given on CR4 for this month!

I know it will be difficult, but next month you must try a little harder to make your answers incomprehensible...

John

I imagine it to arise from printing out the data sheet for a microprocessor with the incorrect format. So that the line headings for two otherwise unrelated features have become merged as if they were a single item. That is:

Arithmetic Unit:
Floating Point . . . . . . . . . . 16 Bits + sign + 12-bit exponent

Power Supply:
Voltage: . . . . . . . . . . . . . 2.7 ... 3.3 Volts
Dissipation: 50-mA max

Otherwise, it could be a misremembering of "Floating Power Supply" or a power supply for recharging boat batteries or ...

Anyone out there got any better idea?

Cynic

Did the answer help you?

Just split up the words in your title:

A power supply: this is I assume OK

Floating point: this means that the absolute level of your power supply voltage is not fixed: it will follow the circuit which needs to be powered.

There are several applications known where it is handy to have your power supply/circuit completely insulated from the environment.

Google a bit on IT earthing systems, you will learn a lot.

Standard terminology is "floating", not "floating point". I think it will cause more trouble than assistance if you use this unusual term in your response. Floating point is applied to formats for numbers, and sometimes to launch positions for ships. I have never previously heard it applied to the absence of a ground connection in an electrical circuit, and hope I never shall again.

Cynic

Sorry I just reused the words in the title.

optimistic

Cool - just trying not to maintain or increase the pre-existing confusion.

Cynic