2 Risposte Punteggio 0 |
New Klein NCVT1P no test sound |
3 Risposte Punteggio 1 |
How to extract PCB from chassis of Fluke VoltAlert 1AC-A II? |
1 Risposta Punteggio 0 |
AC voltage Alert [ IAC-D 90-1000VAC/LED.LIGHT |
Background Information
Amplified electronic testers (informally called electrical tester pens, test pens, or voltage detectors) rely on capacitive current only, and essentially detect the changing electric field around AC energized objects. This means that no direct metallic contact with the circuit is required. The user must touch the top of the handle to provide a ground reference (through stray capacitance to ground), at which point the indicator LED will light up or a speaker will buzz, if the conductor being tested is live. Additional energy to light the lamp and power the amplifier is supplied by a small internal battery, and does not flow through the user's body.
When the device is placed near a live conductor, a capacitive voltage divider is established, comprising the parasitic capacitance between the conductor and the sensor, and between the sensor to ground (through the user's body).[3|new_window=true] When the tester detects current flowing through this divider, it indicates the presence of voltage.