1. A sigma-delta analog-to-digital converter comprising:
a sigma-delta feedback loop of the sigma-delta analog-to-digital converter;
a variable gain amplifier within the sigma-delta feedback loop; and
an attenuator within the sigma-delta feedback loop,
wherein the attenuator is operable to attenuate by an attenuation factor and the amplifier is operable to amplify by an amplification factor, the attentuation factor equal to the amplification factor.
2. The sigma-delta analog-to-digital converter of claim 1 wherein the sigma-delta feedback loop comprises a loop filter, a quantizer, a loop digital-to-analog converter and a summer, the variable gain amplifier positioned prior to the quantizer and after the summer.
3. The sigma-delta analog-to-digital converter of claim 1 further comprising:
an output from the sigma-delta feedback loop;
a processor operable to receive signals on the output and operable to vary a gain of the variable gain amplifier in response to the signals.
4. The sigma-delta analog-to-digital converter of claim 3 wherein the sigma-delta feedback loop comprises a continuous-time sigma-delta loop and wherein the processor is operable to automatically control the gain.
5. The sigma-delta analog-to-digital converter of claim 1 wherein the variable gain amplifier is operable to amplify an output of the sigma-delta analog-to-digital converter, the attenuator operable to attenuate feedback signals for combination with signal input to the sigma-delta analog-to-digital converter prior to amplification by the variable gain amplifier.
6. A sigma-delta analog-to-digital converter comprising:
a sigma-delta feedback loop;
an attenuator within the sigma-delta feedback loop;
a variable gain amplifier within the sigma-delta feedback loop; and
a single digital-to-analog converter in the sigma-delta feedback loop,
wherein the attenuator is operable to attenuate by an attenuation factor and the amplifier is operable to amplify by an amplification factor, the attentuation factor matched to the amplification factor.
7. A sigma-delta analog-to-digital converter comprising:
a sigma-delta feedback loop;
an attenuator within the sigma-delta feedback loop;
a variable gain amplifier within the sigma-delta feedback loop; and
a single loop filter in the sigma-delta feedback loop;
wherein the attenuator is operable to attenuate by an attenuation factor and the amplifier is operable to amplify by an amplification factor, the attentuation factor matched to the amplification factor.
8. A signal path with automatic gain control, the signal path comprising:
an analog device;
a sigma-delta analog-to-digital converter coupled with the analog device, the sigma-delta analog-to-digital converter having a sigma-delta feedback loop, an attenuator and a variable gain amplifier within the sigma-delta feedback loop,
wherein the attenuator is operable to attenuate by an attenuation factor and the amplifier is operable to amplify by an amplification factor, the attentuation factor equal to the amplification factor.
9. The signal path of claim 8 wherein the sigma-delta analog-to-digital converter comprises a loop filter, a quantizer, a loop digital-to-analog converter and a summer, the variable gain amplifier positioned prior to the quantizer and after the summer, and the attenuator is positioned after the loop digital-to-analog converter and before the summer.
10. The signal path of claim 9 wherein the variable gain amplifier is positioned after the loop filter.
11. The sigma-delta analog-to-digital converter of claim 1 further comprising:
a single loop filter in the sigma-delta feedback loop.
12. The signal path of claim 8 wherein the sigma-delta feedback loop includes a single digital-to-analog converter.
13. The signal path of claim 8 further comprising:
an output from the sigma-delta feedback loop;
a processor operable to receive signals on the output and operable to vary a gain of the variable gain amplifier and an attenuation of the attenuator in response to the signals.
14. The signal path of claim 8 wherein the variable gain amplifier is operable to amplify an output of the signal path, the attenuator is operable to attenuate feedback signals for combination with signals input to the signal path prior to amplification by the variable gain amplifier.
15. The signal path of claim 8 further comprising:
at least one of a LNA or an additional variable gain amplifier prior to the sigma-delta analog-to-digital converter, the one operable to partially amplify and the variable gain amplifier operable to partially amplify within the signal path.
16. The signal path of claim 8 wherein the analog device comprises a mixer, further comprising:
a filter between the mixer and the sigma-delta analog-to-digital converter; and
an adjustable gain amplifier between the filter and the sigma-delta analog-to-digital converter.
17. The signal path of claim 8 comprising a mobile telephone receiver.
18. The sigma-delta analog-to-digital converter of claim 1 further comprising:
a single digital-to-analog converter in the sigma-delta feedback loop.
19. The signal path of claim 8 wherein the sigma-delta feedback loop includes a single loop filter.
20. A method for automatically controlling gain with a sigma-delta analog-to-digital converter, the method comprising:
(a) converting analog signals to digital signals with a quantizer of the sigma-delta analog-to-digital converter; and
(b) scaling the digital signals output by the quantizer inside the sigma-delta analog-to-digital converter;
wherein (a) comprises quantizing and summing a sigma-delta feedback signal with input analog signals, and wherein (b) comprises amplifying and attenuating the sigma-delta feedback signal as a function of the amplification prior to quantizing, and
wherein an amount of amplification and amount of attenuation are matched.
21. The method of claim 20 wherein (b) comprises scaling inside a low-pass or band-pass continuous-time sigma-delta loop.
22. The method of claim 20 wherein (a) comprises quantizing the analog signals, and wherein (b) comprises amplifying the analog signals prior to the quantizing.
23. The method of claim 20 further comprising:
filtering with a signal loop filter in a sigma-delta feedback loop.
24. The method of claim 20 further comprising:
converting the digital signals with a single digital-to-analog converter.
25. A method for automatically controlling gain with a sigma-delta analog-to-digital converter, the method comprising:
(a) converting analog signals to digital signals with a quantizer of the sigma-delta analog-to-digital converter;
(b) scaling the digital signals output by the quantizer inside the sigma-delta analog-to-digital converter; and
(c) adjusting the scaling of (b) as a function of the digital signals output by the sigma-delta analog-to-digital converter.
26. The method of claim 25 wherein (b) and (c) comprise automatically controlling gain in a receive path, the receive path including the sigma-delta analog-to-digital converter.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An accessory mounting apparatus for releaseably locking a boat accessory in a selected position, said apparatus comprising:
a base for attaching to a boat, said base adapted to attach to a member on the boat;
a ball head assembly having a ball held captive in a socket, said ball having a locked position and an unlocked position, said ball movable within said socket when said ball is in said unlocked position, said ball held in a fixed position when said ball is in said locked position, said socket having an opening through which a stud member extends from said ball, said stud member adapted to attach to an accessory;
a support member connecting said ball head assembly to said base, said socket rotating about a longitudinal axis of said support member when said ball is in said unlocked position, said socket including a base member attached to a cap member, said base member having an inside ledge cooperating with a flange extending from said support member, said base member being restrained from sliding off said support member by said flange; and
a handle protruding from said base, said handle having a first position and a second position, said ball being in said locked position when said handle is in said first position, said ball being in said unlocked position when said handle is in said second position, said handle causing a first piston to move linearly within a first cylindrical opening in said base, said first piston hydraulically connected to a second piston moveable linearly within a second cylindrical opening in said support member, said second piston engaging a shoe adjacent said ball in said socket, said shoe pressing against said ball in said locked position.
a spring disposed adjacent one of said first piston and said second piston, said spring being outside a hydraulic channel hydraulically connecting said first piston and said second piston, said spring configured to apply a pressure against said one of said first piston and said second piston to maintain a substantially constant hydraulic pressure over an ambient temperature range.
2. The apparatus of claim 1 wherein said stud member is attached to one item selected from a group including a speaker, a light, a mirror, and a tower member.
3. The apparatus of claim 1 wherein said first piston includes a cooperating o-ring engaging a circumferential groove in a cylindrical body of said first piston and said second piston includes a cooperating o-ring engaging a circumferential groove in a cylindrical body of said second piston.
4. The apparatus of claim 1 wherein said socket includes a slot extending from said opening in said slot, said slot sized to receive said stud member.
5. The apparatus of claim 1 wherein said handle is attached to a threaded shaft, said threaded shaft engaging a threaded portion of said first cylindrical opening, said threaded shaft causing said first piston to move linearly as said handle is rotated.
6. The apparatus of claim 1 wherein said handle is attached to a shaft, said shaft having a cam with a lobe engaging said first piston, said cam causing said first piston to move linearly as said handle is rotated.
7. (canceled)
8. The apparatus of claim 1 wherein said base is a clamp for a tubular member, said clamp including a through-opening for receiving a cylindrical member attached to said boat, said clamp further including a first member and a second member for positioning around said cylindrical member thereby securing said clamp to said boat, said support member integral with said base.
9. The apparatus of claim 1 further including an external connection in hydraulic communication with said first piston and said second piston, said external connection for introducing a hydraulic fluid, and said external connection having a removable plug independent of said first and second piston.
10. An accessory mounting apparatus for releaseably locking a boat accessory in a selected position, said apparatus comprising:
a base for attaching to a boat, said base having a handle extending from said base, said handle having a first position and a second position;
a ball head assembly having a ball held captive in a socket, said ball having a locked position and an unlocked position, with said handle in said first position said ball is in said unlocked position and movable within said socket, with said handle in said second position said ball is in said locked position and held in a fixed position, said socket having an opening through which a stud member extends from said ball, said socket including a slot extending from said opening in said slot, said slot sized to receive said stud member, said stud member adapted to attach to an accessory;
a support member connecting said ball head assembly to said base, said socket rotating about a longitudinal axis of said support member when said ball is in said unlocked position, said socket including a base member attached to a cap member, said base member having an inside ledge cooperating with a flange extending from said support member, said base member being held captive on said support member by said flange; and
a first piston moved linearly by a spring actuated by said handle, said first piston hydraulically connected to a second piston in said support member, said second piston engaging a shoe adjacent said ball in said socket, and said shoe pressing against said ball in said locked position.
11. (canceled)
12. The apparatus of claim 11 wherein said handle is attached to a threaded shaft, said threaded shaft engaging a threaded portion of a first cylindrical opening, when said handle is rotated said threaded shaft causes said first piston to move linearly within a portion of said first cylindrical opening with a smooth bore.
13. The apparatus of claim 11 wherein said handle is attached to a shaft, said shaft having a cam with a lobe engaging said first piston, said cam causing said first piston to move linearly when said handle is rotated between said first and second positions.
14. The apparatus of claim 11 wherein said base is a clamp for a tubular member, said clamp including a through-opening for receiving a cylindrical member attached to said boat, said clamp further including a first member and a second member for positioning around said cylindrical member thereby securing said clamp to said boat, said support member integral with said base.
15. An accessory mounting apparatus for releaseably locking a boat accessory in a selected position, said apparatus comprising:
a base adapted to be secured to a boat;
a ball head assembly having a ball held captive in a socket, said socket having an opening through which a stud member extends from said ball, said socket including a slot extending from said opening in said slot, said slot sized to receive said stud member, said stud member adapted to attach to an accessory;
a support member connecting said ball head assembly to said base;
a handle movable between a first position and a second position, said handle extending from said base, said ball movable within said socket when said handle is in said first position, said socket rotating about a longitudinal axis of said support member when said handle is in said first position;
a first piston sliding within a first conduit in said base, said first piston moving linearly in cooperation with said handle;
a spring between said handle and said first piston, said spring partially compressed with said handle in said second position;
a second conduit in said support member;
a third conduit in fluid communication with said first conduit and said second conduit, said first, second, and third conduits containing an incompressible fluid;
a second piston sliding within said second conduit, said second piston moving linearly in direct relation to a movement of said first piston; and
a shoe in said socket, said shoe engaged by said second piston, said shoe having a concave spherical surface adjacent said ball, said shoe forced against said ball by said second piston when said handle is in said second position whereby said ball is locked in a selected position in said socket.
16. The apparatus of claim 15 wherein said socket includes a base member attached to a cap member, said base member having an inside ledge cooperating with a flange extending from said support member, said base member being held captive on said support member by said flange.
17. The apparatus of claim 15 wherein said base includes a through-opening for receiving a cylindrical member attached to said boat, said base further including a first member and a second member for positioning around said cylindrical member thereby securing said base to said boat.
18. The apparatus of claim 15 wherein said base is cylindrical member for mating with a tower section, said support member integral with said base.
19. The apparatus of claim 15 wherein said handle is attached to a threaded shaft, said threaded shaft engaging a threaded portion of said first conduit, as said handle is rotated said threaded shaft causes said first piston to move linearly within a portion of said first conduit with a smooth bore.
20. The apparatus of claim 15 wherein said handle is attached to a shaft, said shaft having a cam with a lobe engaging said first piston, said cam causing said first piston to move linearly as said handle is rotated.
21. The apparatus of claim 15 further including an external connection in hydraulic communication with one of said first, second, and third conduits, said external connection for introducing said incompressible fluid, and said external connection having a removable plug independent of said first and second piston configured to receive said incompressible fluid.
22. The apparatus of claim 15 wherein said first piston includes a cooperating o-ring engaging a circumferential groove in a cylindrical body of said first piston and said second piston includes a cooperating o-ring engaging a circumferential groove in a cylindrical body of said second piston.
23. (canceled)
24. The apparatus of claim 1 wherein said base is a cylindrical base for mating with a tower section, said base coaxial with a mating portion of said tower section.
25. The apparatus of claim 11 wherein said base is a cylindrical base for mating with a tower section, said base coaxial with a mating portion of said tower section.