[SOLVED] tester glow technique ?

[shahbaz.ele]

dear all
can someone explain how tester works?
i.e, it glows light wheen connected to live wire (220V)
shows nothing when connected to ground level.

 

[jeffrey samuel]

The supply current passes through the LED and then a high resistance through our body to the ground this closes the circuit and thus it glow

In neutral lines no power is entering the Testor from the main plug and so it does not glow

 

[manishanand14]

Hi shahbaz.ele !

A neon lamp takes very little current to light.It is connected in series with very high resistance which limits the current at very low value which can't be sensed by human body.

When you touch a live wire the circuit completes through your body and neon lamp lights up to indicate live wire.

It glows only when current flows "which happens when you touch the metal tip of the screwdriver to a live wire" whereas when you touch the tip to ground wire no current flows and hence no glow of the neon lamp.

 

[shahbaz.ele]

Thank you all
|I got it.