Card-operated security system - has coded strips applied to both sides of card and no more than one aligned lamp sensor pair

摘要

A card operated security system has reflective coded strips on the card and optic sensors and lights inside the key slot. If the correct card is positioned in the reading slot then the reflective strips reflect the light to the sensors and complete the code. The simple security system then operates a relay which unblocks the protected circuits e.g. electronic locks, machine switches. The coded strips can be applied to both sides of the card and each side can have more than one lamp-sensor pairs aligned with the strips. The sensors are in series so that the relay is only activated if all the code is correct. ADVANTAGE - Simple technology, suitable for domestic-and amateur use.