In reply to a post by Pheasant:

Here are some other reasonably priced PoE splitters from Planet

Thanks for that, very useful. I'd rather pay a bit more for a brand than a cheap no-name from eBay or Amazon.

OK, so do I have to get a 1 amp for a 1 amp device or can a 2 amp work? Will a 1 amp device just take 1 amp or will it get two and fry?

Obviously I did something silly when connecting the wrong PSU to a radio recently. There was a small spark and the radio was dead. But maybe I tried to use a 12 volt PSU where the radio wanted 5?

I seem to remember its the amps that kill you. But a little knowledge...

2A will be fine - the device will only take as much as it needs.

In reply to a post by Woolwich:

I seem to remember its the amps that kill you. But a little knowledge...

That is true - milliamps to be more precise. However, you still need suficient voltage there to allow te body to conduct.

Most people could safely hold teh two contact of a 12v 10A power supply, one in each hand and feel nothing. But try a 120v 10mA supply and it could well be fatal - so do not try it.

I am no electrician but are your numbers correct? I thought I would look at a livestock electric fence and found this

In reference to www.agrisellex.co.uk/pages/what-is-electric-fencing:

No, an electric fence is not dangerous. The voltage being sent through the wires is high, but the current or amplification (amps) is very low. A 220-volt shock will hurt just as much as a 10,000-volt shock, as long as the current or amps are the same. Amps are what kills. Electric fence energisers put out high voltage (around 8,000 volts), but very low amperage or current (around 120 milliamps). This is 120-thousands of an amp. It should not even kill a squirrel.

That is vastly higher voltage and amperage than your example and yet apparently "wouldn't even kill a squirrel".

For a healthly human it is believed 100mA will be lethal. However, there are people with differing "issues" and sustained 10mA could be enough in their case. RCDs operate at 30mA for most houses and are very rapid. If the body could sustain 100mA then why not make them 100mA and just as rapid? There is good reason why they are don at 30mA. You can also get 10mA one where a higher degree of protection is required.


An electric fence is pulsed and not continuous though. I certainly would not be touching an 8kV 120mA source. And I know what a 10-15kV shock feels like.

In reply to a post by MHC:

But try a 120v 10mA supply and it could well be fatal - so do not try it.

In reply to a post by MHC:

For a healthly human it is believed 100mA will be lethal.

I would be dead 10 times over if that were true.

You might be lucky ... I have been on several occasions.

A US site gives this:

Currents greater than 75 mA cause ventricular fibrillation (very rapid, ineffective heartbeat). This condition will cause death within a few minutes

https://www.elcosh.org/document/1624/888/d000543/sec...

Yes 100mA and 300mA RCD and RCBOs typically used within commercial/industrial settings for the protection of equipment and fire protection rather than safety of life. 30mA is the generally acknowledged upper safe limit for life protection, but can be too sensitive for some circuits / gear which has an inherent amount of leakage. So they set it higher to avoid nuisance tripping.

"It should not even kill a squirrel."

My electric fence killed a hedgehog It also plays havoc with ADSL if anywhere near the phone wires (and probably FTTC too, but we don't have that here).

In reply to a post by Woolwich:

OK, so do I have to get a 1 amp for a 1 amp device or can a 2 amp work? Will a 1 amp device just take 1 amp or will it get two and fry?

Obviously I did something silly when connecting the wrong PSU to a radio recently. There was a small spark and the radio was dead. But maybe I tried to use a 12 volt PSU where the radio wanted 5?

I seem to remember its the amps that kill you. But a little knowledge...

as long as volts is same, and amps is same or more it'll be fine, using 12v on something that needs 5v is likely to break stuff (best case is that a regulator runs a bit hot, worst case is magic smoke get released)