I'm thinking of buying a power supply but I live in an

>>1183424

noobs on this board seem to have a hang-up about grounds. they are absolutely not necessary in this kind of setup. a power supply without a ground is the same as a battery, no better or worse.

in fact grounds can be a problem in test equipment if you go measuring things inside live equipment.

>>1183424
I live in an ungrounded apartment too. The problem with equipment and many appliances is that the neutral is often connected to ground, so if you're using a grounded PSU and touch the positive lead with the scope the current will travel through your scope, through your ground wire and back to your PSU again.

This is usually not a problem if you're dealing with small currents, but it can be pretty dangerous with mains voltage, since a touching mains and the ground lead can result in a bang and possible damage to yourself or the scope. It's essentially like shorting mains to neutral through your scope.

Solutions:
Isolate the ground of your scope.
Install an isolation transformer and use your scope with it.
Disconnect the ground from your PSU's negative output (if possible)

If you're worried about accidental shorts with your PSU you can check if the outputs are connected to ground. To do this, put a multimeter in continuity mode, one at the negative output and another to ground. If there's no continuity you can probe around as much as you want.
This can happen if your PSU is based on a chunky transformer which acts like an isolation transformer and if the negative output isn't connected to ground.

Here, Dave explains it better than me.

https://www.youtube.com/watch?v=xaELqAo4kkQ

>>1183424
What is it with people on here living in houses without proper grounds? Is it a US thing?

>>1183502
Not OP, but >>1183482
I live in yurop, currently living in some apartment building for studies, it's probably constructed 40+ years before I was born. My other newer house has a ground connection though.

>>1183482
Oh good find. So it looks like the PS will be floating and I'll be safe so long as I don't connect the common to ground.

>>1183546
Yeah. It's generally a good idea to not short the equipment that you're using

>>1183505
>>1183502
I live in a house built in - 49 if I recall correctly. Might be - 51 also? There are outlets that have ground but they have been installed later. It seems like lack or ground was a thing back in the day. Suckiest thing is the three phase outlet (which I sadly have only one of), it is a 4 wire setup with just three phases and ground. It means that if you want to take out 3*220V you need to connect the neutral to ground and it's not cool to have a PEN which leads current :/.
I live by the polar circle in joirop.

>>1183702
We could put some spikes into the ground and run a ground wire to the fuse box, but since I live in an apartment building all neigbours must agree to do something to the building and share the cost, and since they're stupid and cheap they don't need a ground connection, at least until someone gets stuck to their fridge, maybe then they'll change their minds.
Living in apartment building full of stupid people is hell on earth, it's like HOA, only your neighbours live above and below you, which is worse.

>>1183424
ground is a safety feature designed to protect humans from voltages on exposed metal surfaces by creating a short in order to operate an overcurrent device. why in the fuck would it be connected to neutral or 0v inside the appliance?
look at page 2-2 under grounding
>either side of the output may be grounded.
they give you the white ground post on the front, you can connect 0v or the positive output to it to give you essentially a negative voltage w.r.t. ground.

>>1183435
>grounds can be a problem in test equipment
only in oscilloscopes are probes ground referenced because they share a common reference and bncs have huge fucking shield sticking out that would be dangerous as fuck to make live. if you look at handheld scope-meters or differential probes you will see protected, plastic shielded probes so you don't accidentally grab them.

>>1183482
>many appliances is that the neutral is often connected to ground
inside the appliance this is best avoided because 1) ground loops 2) its fucking retarded 3) neutral is classed as a live conductor which shouldn't be connected to ground except under fault condition.

>>1183482
>Isolate the ground of your scope.
this is a terrible idea please don't do this
>Install an isolation transformer and use your scope with it.
isolation transformer ON THE APPLIANCE UNDER TEST, NOT ON THE SCOPE

>>1183502
US houses have bare wires in walls strung between ceramic posts. google 'knob and tube' scary shit man.

>>1184380
wow sucks to be you, here in the first world the network operator has to provide a suitable ground connection, if not from source or bonded from a ground referenced neutral then they will sink a ground rod for you.

>>1183502

Grounding wasn't required by US code until the early 1960's, and many homes built before that time still have their original ungrounded electrical systems.

My house was built in 1905- most circuits are ungrounded except for a few that were run specifically for TV and computer equipment.

It would not surprise me at all to see knob and tube in the walls, but thankfully I've never had a reason to open the walls up and check. This is especially true because we have a finished second story on our house, so while it's easy to replace everything in the basement, replacing the stuff between the first and second story generally requires a complete tear-out.

>>1184380
That sounds more like a condominium. Do you rent or 'own' the unit?

>>1183702
Do they really have ground or just a ground slot on the plug? It is not uncommon to find outlets in old homes that were replaced with "grounded" outlets when they wore out but don't actually have a ground wire. Running ground wires is generally not cheap. Test it before you trust it.

>>1183502
It is an old house thing. IIRC Most places in Europe didn't get on board grounded outlets until the after WWII.The fact that the were rebuilding a lot of stuff at the time probably helped adoption. In the USA they started to require grounded outlets in wet areas of the home in 1947. In 1956 it was increased to include 'utility areas' (garages, basements, etc). By 1962 it was all outlets regardless of location. They did a similar phased rollout of GFCI outlets.

>>1184393
Knob and tube wire was originally insulated. It's just since it rolled out in 1880 most insulation has worn off. K&T was last installed in the 1930s. So, it's 80 years old at least.