Deactivator for security strip on saleable goods - has deactivating coil pulsed from thyristor controlled capacitor discharge

摘要

The deactivator circuit consists of a transformer (7) which, via a rectifier (8) and a resistor (9), feeds the oscillatory circuit made up of the deactivating coil (3) and a capacitor (10). The deactivating coil (3) is in series with a thyristor (11), the gate of which, is fed via two microswitches (12,13) from one side of the circuit rectifier (8). When the microswitches (12,13), which are in series, are closed, a magnetic field builds up in the deactivator coil (3) in less than a millisecond, due to the discharge pulse of the capacitor (10). Sharply defined magnetic zones arise, which cannot be changed by incorrect use of the deactivator. Other models of strip deactivator can be constructed for books, records, music cassettes. In the case of the latter, the form is such, that the recording on the tape itself is not damaged during deactivation of the strip.