US 5,398,798 A · Electronic circuit protection automatic power interrupt

Abstract

A device for use with a machine, such as a vending machine, automatic teller machine, change machine, cash register, game machine, personal or business machine or the like, having a cabinet containing machine electrical circuits and a door and at least one possible point of entry through the cabinet and door by foreign substances into contact with the machine electrical circuits to cause their operation in violation of machine protocol, minimizes the damage caused by such protocol violations. The device interrupts the AC power to the machine electrical circuits in response to sensors disposed as close to the points of entry as possible. Thus, all machine circuits are shut down before damage can occur. At least one sensor proximate each of the points of entry detect the penetration of the foreign substances and initiate generation of an electrical control signal for operating the interrupt to disconnect the machine circuits from the AC power source. The control signal is generated continuously after detection of penetration of a foreign substance, even after the substance has cleared the sensor. An alarm is connected in series with a switch to the machine AC power source on the power side of the interrupt and the switch is normally open to deactivate the alarm and closes in response to the control signal to activate the alarm. A timing signal commences substantially simultaneously with the control signal and discontinues after a preselected time, discontinuance of the timing signal resulting in deactivation of the alarm after the selected period of time.

Claims12

Dependent claims

For use with a machine having a cabinet and machine electrical circuits contained therein connected to an AC power source and having at least one possible point for penetration through the cabinet of foreign substances into contact with the machine electrical circuits to cause their operation in violation of machine protocol, a protection device comprising:

an interrupt for series connection between the AC power source and the machine electrical circuits;
a DC power source;
at least one sensor means connected to said DC power source and disposed proximate at least one of the points of penetration for detecting the penetration of at least one of the foreign substances therein and for generating an electrical control signal in response to detection of penetration of at least one of the foreign substances, said sensor means generating said control signal continuously after detection of penetration of at least one of the foreign substances;
and
means responsive to said control signal for operating said interrupt to disconnect the machine circuits from the AC power source.

2 more elements

For use with a machine having a cabinet and machine electrical circuits contained therein connected to an AC power source and having at least one possible point of entry through the cabinet of foreign substances into contact with the machine electrical circuits to cause their operation in violation of machine protocol, a protection device comprising:

means series connected between the AC power source and the machine electrical circuits responsive to an overload of the AC power source to interrupt power to the machine circuits;
switching means connected in parallel with the machine circuits on a load side of said interrupt means in normally open condition for short-circuiting said AC power source and said interrupt means when said switching means is in a closed condition;
a DC power source;
first voltage divider means connected between said DC power source and said negative comparator input having at least one sensor electrically connected therein and disposed proximate at least one of the points of entry for becoming electrically conductive upon penetration of at least one of the foreign substances into contact therewith;
second voltage divider means connected between said DC power source and said positive comparator input having a variable resistance for setting the resistance point at which said comparator generates a sensor signal at said output;
means having a positive input connected through said second voltage divider means to said DC power source and a negative input connected through said first voltage divider means to said DC power source for comparing said inputs and for generating an electrical sensor signal at an output thereof when said positive input exceeds said negative input;
and
means connected to said comparator means output and responsive to said sensor signal for switching said normally open switching means to said closed condition to overload said interrupt means to disconnect the machine circuits from the AC power source.

5 more elements

Dependencies are inferred from the claim text.

Electronic circuit protection automatic power interrupt

Life of this patent

Electronic circuit protection automatic power interrupt

Life of this patent

Abstract

Claims12