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Peter Green
Peter Green
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Short answer: it's fine to touch them.

Longer answer:

Roughtly speaking the current through the body depends on three things. The open circuit voltage of the power supply. The source impedance of the power supply and the impedance of the human body.

The impedance of the human body varies a lot depending on contact area, presense of moisture on the skin etc and this makes it difficult to have hard and fast rules on what is safe but the general rule of thumb is that 50V is about the point where you need to start seriously worrying about electric shock risk. 5V is an order of magnitude lower than that.

A lot of people seem to think that high current supplies are more of a shock risk than low current ones. This is true if we are talking about extremely low current supplies but there is going to be negligable difference in tissue current between touching a 5V 100ma supply and a 5V 100A supply. In both cases the source impedance of the supply will be negligable in comparision to the impedance of the body.

Having said that while high current 5V supplies aren't a shock risk under normal conditions they can be a fire and burn risk. IIRC people have had serious burns when jewlery has shorted out high current supplies. If you are deploying large numbers of these LEDs I would suggest splitting their power supply into groups with each group fused at no more than a few amps.

Short answer: it's fine to touch them.

Longer answer:

Roughtly speaking the current through the body depends on three things. The open circuit voltage of the power supply. The source impedance of the power supply and the impedance of the human body.

The impedance of the human body varies a lot depending on contact area, presense of moisture on the skin etc and this makes it difficult to have hard and fast rules on what is safe but the general rule of thumb is that 50V is about the point where you need to start seriously worrying about electric shock risk. 5V is an order of magnitude lower than that.

A lot of people seem to think that high current supplies are more of a shock risk than low current ones. This is true if we are talking about extremely low current supplies but there is going to be negligable difference in tissue current between touching a 5V 100ma supply and a 5V 100A supply.

Having said that while high current 5V supplies aren't a shock risk under normal conditions they can be a fire and burn risk. IIRC people have had serious burns when jewlery has shorted out high current supplies. If you are deploying large numbers of these LEDs I would suggest splitting their power supply into groups with each group fused at no more than a few amps.

Short answer: it's fine to touch them.

Longer answer:

Roughtly speaking the current through the body depends on three things. The open circuit voltage of the power supply. The source impedance of the power supply and the impedance of the human body.

The impedance of the human body varies a lot depending on contact area, presense of moisture on the skin etc and this makes it difficult to have hard and fast rules on what is safe but the general rule of thumb is that 50V is about the point where you need to start seriously worrying about electric shock risk. 5V is an order of magnitude lower than that.

A lot of people seem to think that high current supplies are more of a shock risk than low current ones. This is true if we are talking about extremely low current supplies but there is going to be negligable difference in tissue current between touching a 5V 100ma supply and a 5V 100A supply. In both cases the source impedance of the supply will be negligable in comparision to the impedance of the body.

Having said that while high current 5V supplies aren't a shock risk under normal conditions they can be a fire and burn risk. IIRC people have had serious burns when jewlery has shorted out high current supplies. If you are deploying large numbers of these LEDs I would suggest splitting their power supply into groups with each group fused at no more than a few amps.

Source Link
Peter Green
Peter Green
  • 23.1k
  • 1
  • 41
  • 86

Short answer: it's fine to touch them.

Longer answer:

Roughtly speaking the current through the body depends on three things. The open circuit voltage of the power supply. The source impedance of the power supply and the impedance of the human body.

The impedance of the human body varies a lot depending on contact area, presense of moisture on the skin etc and this makes it difficult to have hard and fast rules on what is safe but the general rule of thumb is that 50V is about the point where you need to start seriously worrying about electric shock risk. 5V is an order of magnitude lower than that.

A lot of people seem to think that high current supplies are more of a shock risk than low current ones. This is true if we are talking about extremely low current supplies but there is going to be negligable difference in tissue current between touching a 5V 100ma supply and a 5V 100A supply.

Having said that while high current 5V supplies aren't a shock risk under normal conditions they can be a fire and burn risk. IIRC people have had serious burns when jewlery has shorted out high current supplies. If you are deploying large numbers of these LEDs I would suggest splitting their power supply into groups with each group fused at no more than a few amps.