Security circuit with magnetic proximity sensor having a magnetic settable and electrical resettable latched output

A security circuit for use with a voltage source comprising:

• A Hall-effect sensor for generating an output signal in response to a sensed variation in the strength of a magnetic field proximate to said Hall-effect sensor and said Hall-effect sensor being adapted to be connected to a voltage source;
• latch means for receiving said Hall-effect sensor output signal and for generating a latched output signal, said latch means operable between a set state and a reset state;
• means for monitoring the voltage source independent of the magnetic field and for generating an output signal applied to said latch means when the voltage source is below a predetermined value;
• and
• said latch means generating said latched output signal to said set state in response to said sensor output signal and said latch means generating said latched output signal to said reset state in response to said monitoring means output signal when the voltage source is below said predetermined value.