Shallow depth lead weight ejection circuit

A circuit for ejecting ballast weights when an underwater, self-powered vehicle fails during operations which comprises:

• an astable multivibrator connected to receive power from the basic power source of the underwater vehicle, and connected in parallel with a first RC circuit to establish that the output signal from said astable multivibrator will be periodic at a predetermined period T;
• a first NAND gate having both input terminals connected to a first output terminal of the astable multivibrator to receive the periodic signal, said NAND gate inverting the input signal;
• a second NAND gate having a first input terminal connected to the first output terminal of the astable multivibrator and having a second input terminal connected to receive the output signal of the first NAND gate;
• a second RC circuit connected between the output of the first NAND gate, the basic power source, and the second input of the second NAND gate, said second RC circuit adjusted to cause a delay in the signal output from the first NAND gate of a predetermined amount;
• a PNP transistor having its base connected to the output of the second NAND gate, and having its emitter connected to the positive side of the basic power source;
• a first NPN transistor having its base connected to the collector of the PNP transistor, having its emitter connected to the low side of the basic power source, and having its collector connected to one side of the underwater vehicle's depth transducer;
• a voltage dividing network connected with a first terminal of the collector of the first NPN transistor, connected with a second terminal to a ground point, and fitted with an output terminal adjusted to emit a preselected voltage level;
• a comparator with a first input connected to the output terminal of the voltage divider, and a second input connected to a terminal of the depth transducer which transmits a voltage that is sensitive to the depth of the underwater vehicle, said comparator being enabled to emit output signals when the voltages compared at the input terminals indicate the underwater vehicle is below a preset limit depth represented by the output voltage of said voltage divider, said comparator connected to emit an output signal to the base of the PNP transistor, said comparator connected to receive a signal from the collector of said PNP transistor whereby said received signal will turn on said comparator for operation if said comparator is not otherwise inhibited from operating;
• means, connected between the underwater vehicle's operational power circuit and the comparator, for inhibiting operation of the comparator when the operational power circuit is functioning properly;
• a third NAND gate with its first input terminal connected to the second output of the astable multivibrator and its second input terminal connected to the collector of the PNP transistor, said NAND gate emitting an output signal when its two inputs are low;
• a second NPN transistor with its base connected to the output of the third NAND gate and its collector connected to an output of the comparator, said transistor being activated while the comparator is active and a control signal has been emitted from the output of the third NAND gate;
• a third NPN transistor with its base connected to the emitter of the second NPN transistor and its emitter connected to the negative side of the basic power source, said transistor when activated by a signal from the emitter of the second NPN transistor emits a command signal at its collector terminal;
• and
• means, connected to receive the command signal emitted at the collector of the third NPN transistor, for releasing the weights upon receipt of said command signal.