Touch operated table lamps

[electricdave]

Hi,
A mate brought a touch operated table lamp to repair.
I was horrified to see the brass which you touch to operate the lamp is NOT earthed,but is connected to the circuit board,which is live at 230 volts.
Dangerous or what!!!

Dave

 

[ban-all-sheds]

If it was earthed it wouldn't work, would it....

 

[bernardgreen]

but is connected to the circuit board,which is live at 230 volts

Hopefully the touch metal is connected only to a very high and good quailty resistor. It should be at least one meg ohm so the maximum worst case current that can flow through the fingers is less than 230 micro amps. That would be when the person was holding onto an earth appliance with their other hand. I seem to recall the touch lamp my daughter has is fitted with a 12 meg resistor, max current 20 micro amps so quite safe when used as intended.

 

[ban-all-sheds]

I wonder if electricdave has, or has ever had, a neon screwdriver?

 

[Taylortwocities]

Ora digital one

 

[Astra99]

These @%$$!& touch-lights! When they go faulty surely they should fail-safe and go open-circuit! Not one that we had. Touched it and got a "bite" Taught my grandson a new word! Chopped out the circuitry in the base, put in 3-core flex with an in-line switch (still 2-core up the stem to the double-insulated lampholder - soldered connections) and a CFL lamp! Works a treat.

 

[electricdave]

Hi
ASTRA99 has proved they are not save.
I have been an electrician for many years and PAT tested 1000,s of appliances.
REgards
Dave

 

[sparkticus]

I thought the internal PSU is supposed to be SELV on these types of lamps?