This metal detector principle discussed below is fairly well-known, as can be seen in the block diagram in Figure 1. The detector is made up of a large coil acting as an antenna, which is coupled with a capacitor and an amplifier to form an LC oscillator. When the antenna coil approaches a metal mass, […]
BFO
Single Transistor BFO Metal Detector Circuit
The following design below becomes a simple metal detector when it is coupled with a nearby radio receiver that serves as both a detector and an amplifier. Working Principle The circuit utilizes a single transistor configured as an RF oscillator connected to a search coil inductor. When powered, it radiates a high-frequency electromagnetic field. A […]