Help thinking about Grounding/Safety for LED device

MisterBill2

Joined Jan 23, 2018
19,466
Hello - I'm creating an LED device and I'd like to have a good understanding of grounding/safety so I don't accidentally harm my users!

I'm powering my device with an AC/DC wall mount adapter that outputs 20V which connects to a barrel jack on my PCB. I'm using an LED driver as well that outputs 700mA constant current. My LED itself has a forward voltage of 17.2V at 700mA at test temperature (85C).

I connect to my LED with wires off-the-board. I'm using screw terminal blocks on the board itself as this seems to be the most secure connection. And I solder my output wire leads to the LED for a secure connection.

However, I'm using aluminum for the light stand itself and I'm worried one of the LED hot wires could potentially become disconnected from the LED and then make a connection to the aluminum enclosure, giving it a voltage potential. And then when a user touches the device, they could become shocked.

How can I make sure nothing catastrophic can take place? My understanding is that to ground a device, a wire from the metal enclosure should be connected to the ground plug in the AC plug, so if the enclosure gains a voltage potential, it will be dissipated through the ground wire.

However, in my case I'm using the AC/DC wall mount adapter so I'm only dealing with DC within my device.

As you can see, I'm a novice so any tips or pointing me in the right direction would be much appreciated.
The solution to avoid any possible shock hazard is quite simple. Use a medical grade DC power supply, available from DigiKey and many other sources. That will assure that any leakage current is very small and non-hazardous. The 20 volt output will be totally isolated from the mains.
 
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