Automatic electronic lock off system for an appliance

Details Automatic electronic lock off system for an appliance Automatic electronic lock off system for an appliance

1975-06-06

1977-01-11

Caldwell, John W.

Communications: electrical

Land vehicle alarms or indicators

Internal alarm or indicator responsive to a condition of the...

340280, 307142, H01H 4704

Patent

active

040029565

ABSTRACT:
Apparatus for the prevention of theft of electrical appliances comprises an automatic electronic lock off system which may be activated in a particular manner after the appliance is connected to a source of electrical power, and which becomes deactivated when the appliance is disconnected from its source of power to cause the further disconnection in the appliance electrical circuit. The apparatus comprises essentially three components, a key-operated activator switch, a relay, and the appliance's own on-off switch, all connected with the appliance's own circuit leads in a particular manner. The key-operated activator switch is designed to be operated with its own individual key and may, if desired, be hid from view. Initially, the key-operated activator switch is briefly closed to complete a circuit with the coil of the relay. Activation of the relay closes a normally open switch in series with the appliance on-off switch to permit the appliance then to be operable. Consequently, disconnection of the appliance from its source of power causes deactivation of the relay and opening of the normally open switch. Then, if the appliance is subsequently plugged into its source of power, the appliance circuit will be capable of being completed only when the key-operated activator switch is again closed.

REFERENCES:
patent: 2874376 (1959-02-01), Spenard
patent: 3319128 (1967-05-01), Nilssen
patent: 3425050 (1969-01-01), Tellerman et al.
patent: 3718839 (1973-02-01), Conti

Affiliated with

Also associated with

Rating

Automatic electronic lock off system for an appliance does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Automatic electronic lock off system for an appliance, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic electronic lock off system for an appliance will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1745830