220V live wire-in-wall scanner
description
This little circuit will help you to scan the line of a 220V
live wire in the wall. The FET gate is connected to a capacitive
metal sensor (which is usually a simple metal plate). When you
hold the sensor close to the wall, the LED
will indicate the current flow around where it detects the wire.
Works on 9VDC.
Schematic diagram
| component |
value |
| R1 |
15M |
| R2 |
1.8k |
| R3 |
1M |
| R4 |
470 |
| P |
10k |
| D1 |
1N4148 |
| D2 |
1N4148 |
|
| component |
value |
| C1 |
2.2u |
| C2 |
100n |
| C3 |
22u |
| T1 |
BF244 |
| T2 |
BC182B |
| T3 |
BC182B |
|
Peter's electronic projects