Claims
- 1. Means to produce electrical voltage variations indicative of the intensities of earth tremors in the area in which said means is disposed, and to transmit said voltage variations to a receiving station for recording and observation, said means comprising:
- a. a battery power source;
- b. a radio frequency transmitter;
- c. first switching means, said first switching means being connectedly interposed between said battery power source and said transmitter, and said first switching means having a first and normally set position whereby the flow of current from said battery power source to said transmitter is interdicted, and a second position to which said first switching means may be temporarily switched whereby such current flow may occur thereby to initiate operation of said transmitter;
- d. a permanent magnet, said magnet providing a magnetic field about a predetermined axis;
- e. a coil of wire, said coil being suspended within said field to oscillate, when jarred, along said axis, and thereby produce a flow of current in said coil;
- f. current responsive relay means, the last said means being connected to opposite terminals of said coil and operatively associated with said first switching means in such manner that when current of a predetermined amperage flows in said coil, said switching means is moved from its first to its second position and retained in the latter position for a predetermined interval after current of such predetermined amperage ceases to flow in said coil;
- g. second switching means, said second switching means being movable from a normally set first position, to a second position;
- h. first resistance element, said first resistance element being normally connected across the opposite terminals of said coil by said second switching means in its first position, to effect electrical damping of oscillations of said coil within said magnetic field until acceleration applied to said coil shall reach a predetermined value, whereupon said first switching means is moved from its first position to its second position;
- i. a second resistance element, said second resistance element being connected across the opposite terminals of said coil by said second switching means when in its second position, said second resistance element being of a different ohm value from the first resistance element, thereby to dampen the oscillation of said coil on a lesser basis than the damping effected by the first resistance element; and
- j. amplifier integrator means, the input side of said amplifier integrator means being connected across said second resistance element, and the output side of said amplifier integrator means being connected to the input side of said transmitter, thereby to amplify the voltage variations generated in said coil during any oscillation thereof within said magnetic field when the second switching means is in its second position, and to deliver a current with such variations to the transmitter so that radio frequency signals corresponding to said voltage variations may be transmitted by said transmitter to said receiving station.
PRIOR RELATED APPLICATION
This is a divisional application of application Ser. No. 298,536, filed Oct. 18, 1972, now U.S. Pat. No. 3,877,256, which is a continuation-in-part of application Ser. No. 96,325, filed December 9, 1970, which application has been abandoned.
US Referenced Citations (6)
Non-Patent Literature Citations (1)
Entry |
"Small Earthquakes Observed with Local Seismometer Networks", Crampin et al, Philosophical Transactions of the Royal Society of London, Series A, vol. 274, no. 1239 (1973), pp. 383-387. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
298536 |
Oct 1072 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
96325 |
Dec 1970 |
|