Abstract: A water-actuated, pressurized gas release device (10) that automatically actuates to inflate an associated personal flotation device when immersed in an electrically conductive fluid, such as salt or fresh water, is described. The device is comprised of a high strength plastic housing (12) that holds an enclosure tube (62) housing a primer charge (68) in a longitudinal alignment with a piercing pin (44). The primer is connected to a lever (80) and a lead wire (84) that is electrically connected to an electrical circuit means (87) which is in electrical contact with a pair of batteries (118A, 118B). When the device is immersed in water, an electrical circuit is formed between a terminal (122) of the battery pack and the lever and lead wire which serve as an electrical return to the electrical circuit means.

Abstract: A circuit for operating a load in response to predetermined external conductivity conditions comprising a pair of sensing electrodes, a source of electrical energy connected to one of the electrodes, a load connected to the other of the electrodes, a controlled switch connected to the load, a first energy storage branch having a timing chracteristic and connected between the source and the other electrode, a second energy storage branch having a timing characteristic and connected across the combination of the load and a controlled switch, and a control operatively connected to the first and second branches and connected in controlling relation to the controlled switch so that when the electrodes are exposed to a first medium having a predetermined electrical conductivity energy builds up on first and second branches and the controlled switch is open and then a predetermined time after the electrodes are exposed to a second medium having a different electrical conductivity the controlled switch is closed and

Abstract: A circuit for operating a load device comprising an operating circuit including an energy storage device for providing electrical energy for operating the device and a voltage responsive switch having a control terminal and connected between a voltage source and energy storage device of the operating circuit to provide energy to the storage device and opening when the stored energy causes the voltage on both sides of the switch to be essentially the same thereby disconnecting the source from the operating circuit so that any short circuit in the load does not affect the source or the remainder of the circuit associated therewith.

Abstract: A circuit for operating a load in response to predetermined external conductivity conditions including a pair of sensing electrodes, a source of electrical energy connected to one of the electrodes, a load, an operating circuit connected to the load, to the source and to the other of the sensing electrodes and including a first portion for storing electrical energy for operating the load and a second portion utilizing the stored energy to operate the load, and a control for allowing operation of only the first circuit portion when the sensing electrodes are exposed to a first medium having a predetermined electrical conductivity and then allowing operation of the second portion thereafter and when the sensing electrodes are exposed to a second medium having a different electrical conductivity.

Abstract: A circuit for sensing the electrical conductivity of fluid comprising a pair of electrodes adapted to be exposed to the fluid, a voltage source connected to one of the electrodes, a load connected to the other of the electrodes, a firing circuit branch including a firing capacitor connected to the other electrode, a conductivity sensing circuit branch including a sensing circuit capacitor connected to the other electrode and to the voltage source, and characterized by a switch connected in controlled relation to the sensing circuit branch and in controlling relation to the firing circuit. In response to the electrodes being exposed to fluid having a predetermined condition of electrical conductivity, current flows in the sensing circuit branch which operates the switch to connect the firing circuit in a manner preparing it for firing, i.e. charging the capacitor therein. After a predetermined time, i.e.

Abstract: A method and apparatus for testing a circuit which senses the condition of an electrical quantity, the sensing circuit having a sensing portion which indicates a predetermined condition of the electrical quantity of a load connected between a pair of sensing terminals, and having a current conducing device which is activated a given time after the sensing portion indicates the predetermined electrical condition. The testing apparatus includes a network which is connected to the sensing circuit terminals for simulating a load having the electrical quantity to which the sensing circuit is responsive, the network having at least one branch which simulates the existence of the predetermined condition in the load, and the network having a timing component causing the predetermined condition to be simulated for a time adequate to test the sensing circuit response but inadequate to provide sufficient energy to activate the device.

Abstract: Apparatus for sensing the electrical conductivity of fluid which can be used to detonate an electro explosive device for operating a release mechanism for uncoupling a parachute canopy from its load upon landing in water. An operating network connected to an ignition capacitor and to a conductivity sensing circuit and connected in controlling relation to a semiconductor switch has a voltage independent portion which controls the time at which the semiconductor switch is closed to define a discharge path to detonate the electro explosive device independent of the rate of voltage rise on the ignition capacitor. The operating network also has a voltage dependent portion which when a voltage of predetermined magnitude is developed on the conductivity sensing circuit in response to fluid not having the predetermined condition of conductivity, the voltage dependent portion closes the semiconductor switch to define the discharge path when the energy level is insufficient to detonate the electro explosive device.

Abstract: Apparatus for sensing the electrical conductivity of field including a pair of electrodes and a capacitive type conductivity sensing circuit which in response to the electrodes being exposed to fluid of predetermined minimum conductivity under conditions involving a predetermined minimum rate of change of conductivity applies a gating voltage to the control terminal of a semiconductor device switching it into conduction to define a current flow path through a load. The load can be an ignition capacitor for an electro explosive device which, in turn, can be employed in a release mechanism for uncoupling a parachute canopy from its load upon landing in water. A semiconductor switch defines a discharge path for the ignition capacitor through the electro explosive device.

Abstract: A water activated pressurized gas release device, especially suited for automatically controlling the release of the pressurized gas for inflating flotation equipment when dumped into water, which includes an electrically fireable primer for generating propulsion gas to drive a piercing pin into the closure of a container of pressurized gas to release the same, and fired by electrical energy derived from a battery arranged in a circuit maintained open on the ground side by electrically conductive elements providing two spaced apart electrodes until such space is filled with water for a predetermined duration of time as occurs upon immersion to close the circuit.