I asked this before, but I think on alt.usage.english, and never found a word for it.
Say you connect a device to a battery, and in doing so, the connection goes on then off then on then then off because of a bad connection while you're tightening it. What word would describe that?
You are making an intermittent contact with a fluctuating contact resistance.
You are clearly using a bad connector or a poorly designed switch. Poorly engineered contacting system is a trifle more formal. Bodged connection would be less formal.
Another one of that birk's screw ups would be the term we'd use here.
Contact bounce.
Cheers
Phil Hobbs
It is described as 'stupid'.
You're not supposed to be screwing down live connections, by design.
If it's off, then making a few extra connections before energising the circuit won't take much longer to sequence to the 'on' state.
Arc-free, bounce-free or semiconductor switches can be employed, to absorb or control the 'intermediate' connection loss.
Capacitors can be precharged to avoid contact damage by inrush. Loads can be delayed by soft-start, to avoid operating current flow in mating contacts.
Review uninterruptible or redundant power systems and hot-swapping.
RL
Fine, consider a household lightbulb. You screw it in without turning off the power. Or any device in Merka where they don't have switches on the outlets.
Or in my case, plugging 12V PCI-E power connectors into a GPU card while the PSU is live (since it powers 10 others).
Another one - connecting or disconnecting a car battery. The car has always-on loads, as evidenced by a small spark when you connect it.
Not on my machines you don't.
GPU cards are generally not hot-swappable and don't involve scews
The power connectors are latching, for good reasons.
Power your device down - install the hardware - turn it on.
. . . but read the manual first.
RL
Nothing is on, if the battery's not connected, but the always-on loads are low enough to allow precharge, if you think that the delicate lugs and clamps are being damaged by what you see happening there.
My consolations for your perilous dilemma.
Disconnect the battery, while running, and watch the fun . . . .
RL
Why would you equate latching with powering down?
Wow, you really are a rule stickler.
GPU cards are very hot swappable. I bet you actually plug yours straight into the motherboard? I have connected 12 cards at once to one machine.
BUT!!!!! READ THIS!!!!!!!
Answer my original question. Stop messing around saying I shouldn't be doing it. I WANT A SIMPLE ANSWER. What is the word for a connection as above?
F*ck me you're beyond a joke. Let me make this simpler for you. The loads are already connected to the wire you're in the process of attaching to the battery. As you connect the wire, current flows. A spark, an uneven current flow.
Not talking about damage to the lugs, talking about damage to the electronics.
Nothing happens. The alternator continues to power everything. This guy has terrible English, but just watch as his car continues to run.
When you're connecting a battery to a system or converter with considerable local decoupling or capacitive storage, make sure that the system or converter is off.
Precharge the system through a 10 ohm 1/4 resistor. If it pops or burns, you've got a fault or a backwards harness.
RL
I was working on a design that had a significant lead acid battery and a motor with some 10,000's of uF on the rail for the motor controller. I tried to explain to people the surge current could easily exceed the rating of the caps, but one designer waved his hands over it mumbling parasitic resistance and inductance, ignoring the actual numbers I found for the few connectors and wiring. I don't know how they finally disposed of the design. The tried to get them to use a particular connector for the battery, which had a sort of pin and sleeve on one of the two contacts. The first contact was through a resistor, which would limit the initial current, with subsequent full current with no resistor. This would only be an issue when first installing the battery, or when replacing it in the field. Depending on someone to manually connect through a resistor is idiotic. It's not like people reliably read installation manuals.
It's a pre-charge, whether attempted through mating hardware or just done manually, by habit.
The best of us can make a mistake. I've gone to a lot of trouble at times, specifically marking the polarity of new test cables, only to discover that I've meticulously marked them backwards. Popping prechargers told me I'd done something stupid, without killing anything else.
In development work, I'm connecting/disconnecting a 400 Abattery bank maybe two dozen times a day, with nuts and bolts designed for end-use. I keep a few precharging resistors on-hand, just to save the cosmetic finish on my shunts and connector terminals.
Precharging on backplane pin lengths for hotswaping modules in a live system is a technique that will only work if the insertion speed is moderate and the mech guides are uncompromised.
Precharging on manually forced connector shells is hit and miss, depending on the quality of the shells employed. Forget plastic.
RL
Good idea, although I don't seem to have busted my car doing it yet - I do it every time I use it, since something drains the battery at up to 4 amps with all the fuses removed. I'm guessing alternator or alarm.
Anyway, what's the word for doing this?
You'd probably need a German dictionary to come up with a single word.
In AC power it's synchronous transfer. In DC power it's arc-free transfer.
RL
Amazing, the English language has a huge number of words, mind you most of them are duplicates.
That sounds ambiguous. Transfer could mean the transfer of power from A to B, along something already connected.
Google 'transfer switch'.
RL
A lightning strike is a DC transfer. Its hardly 'arc free'. Commander Kinsey is off his meds again
Yes:
"Wackelkontakt" -- literally, "wiggly contact", thus loose contact.
HTH,
Thomas Prufer
WTF? This conversation was not about a particular device. I wanted to know a word in English used to describe when a live connection is made but not smoothly, causing an uneven change from zero to full voltage.
If you want to rule me out of the equation, take a look at some Youtube videos of the huge lever switches used by power companies to switch the HV in transmission lines, and the arcs they create.
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