I have a hi-fi system at home and if I want to connect my DJ controller to my amplifier via cinch, I get a slight electric shock if I touch the cable ends and the housing at the same time.
Is that normal? This does not happen with my turntable / bluetooth receiver and television cables. They are also all connected to the other inputs.
Could it have something to do with the fact that the controller is powered by USB from the laptop and is therefore not directly connected to the socket?
A shock is really different than if it just tingles a bit… You don't die that fast!
No tingling, I know that… I'm talking about a shock of strength that makes your arm twitch…
Yes, if devices are supplied by different power supplies and these are then connected, depending on the circuit technology (and quality) of the power supplies, small currents can develop on the ground lines. This can also create so-called "hum loops", which can lead to puzzling mains hum phenomena.
With a multimeter you can measure the voltage and current between the DJ controller and amplifier. Sometimes it helps to simply turn one of the power plugs.
Through. The devices have line filters, which can lead to a slight capacitive coupling. The transformers in the devices can also contribute to this effect.
However, this should not be dangerous as a rule.
Poor black cat… That's the definition of shock, according to Google: definition shock
A shock is a circulatory failure which, if left untreated, can lead to multiple organ failure (= failure of all organs). Due to a disturbance in the microcirculation, i. A reduced blood flow in the smallest blood vessels means that the tissue receives less oxygen than it needs (hypoxia).
So if you describe a twitch of the arm as a shock, then I don't know! You are scared because sometimes differences in potential are noticeable. Sometimes more, sometimes less… But just a tingling sensation. If you grab hold of it and are prepared for it, nothing twitches.
I don't compare "my little toe pounded on the bedpost at night" with "ran into a mine"!
I just measured it with a multimeter. Short peak up to approx. 55V then immediately 0V again
But it is already clear to you that you are using a multimeter to load the voltage source with a very, very high resistance and that almost no current flows. But if you feel a tingling sensation, electricity flows… And even a small amount of electricity causes the voltage to drop noticeably. Measure that with a pointer measuring instrument and you will get low values.
No matter; it is not dangerous… If it answers your question so far satisfactorily… Before it goes into Ohm's law!
Thank you yes she is. I'm now assuming that this current will be diverted via the power supply of the amplifier anyway. I was just surprised that it can "knock you out" like that.
That is normal".
Audio equipment and most entertainment equipment are not grounded. As a rule, they all have a Euro plug (without a protective contact). This is done to prevent hum loops in the signal cables.
In order to suppress interference and to protect against static charge, the ground is usually connected to L and N of the connector with a small capacitor each.
These capacitors form a so-called "capacitive voltage divider", which means that 115V (half of 230V) that can't be loaded are applied to the ground and to the housing.
With "not loadable" it is meant that only a fraction of 0.1mA can flow between the housing and the earth (or through you). Body currents of less than 0.1mA are regarded as "absolutely harmless".
The problem here is "per device", if you put devices together, then these maximum possible currents add up and quickly come to the area where you can clearly feel them. With an extremely large number of devices, the 0.1mA is clearly exceeded, which can then even be life-threatening.
For this reason, special precautions and safety measurements must be carried out at major events and in studios where a large number of devices are plugged together. It becomes really questionable in tenements where a lot of devices are connected to one another via the antenna system. If the grounding of the antenna system fails or it was not grounded in the first place, this can quickly become life-threatening!
In your case, your laptop is definitely grounded so that its ground is directly connected to the protective conductor. This means that you are particularly well-grounded when you touch your laptop and you get a particularly high leakage current. You are poorly grounded through your socks, carpet, etc., and you get a much smaller current from which you can't feel it.
Where is the protection against dangerous touch voltages? As with every electr. In the event of a fault, the device can have dangerous voltage on the housing if there's no earth.
These devices belong to "Protection Class II". Everything in there that has to do with the phase is structured in such a way that no current can reach the housing even with "normal" defects.
Devices that are badly damaged are not allowed to be used. Any damage that can lead to electric shock is visible from the outside, i.e. Broken housing, defective cables, etc.
Of course, the device can also be damaged during transport in such a way that something breaks off inside without being visible from the outside, but then you can hear something rattling in it when you move the device. Anyone who sets up such a damaged device and puts it into operation is responsible for all consequences! Therefore all devices in companies have to be checked regularly according to BGVA3 if someone sets up a defective device with the reason "nobody notices anyway, it's not that bad, it works".
Of course there's always a certain residual risk, hence the modern regulations that every new installation must have an FI (or RCD).
Although I have some doubts about some protection class II devices when I look at them more closely.
What is prescribed and what is actually done… Have a look at how a car is driven - still ask?
Thank you for the great answer!
