Telemetric receiver

Claim 2

A telemetric receiver for transmitted signals having modulated widths comprising a. a clock pulse generator (22); b. a binary counter (23) capable of being reset to zero by a reset pulse: c. a binary memory register (25) connected with the counter and serving, upon receipt of a latch pulse, to store the count present in the counter; d. means (21) for delivering clock Pulses to the counter during a time interval corresponding to the width of the transmitted signal; e. a latch pulse generator (24) effective at the end of each transmitted pulse to supply a latch pulse to the register and effect transfer thereto of the count in the counter; f. a reset pulse generator (26) effective to supply a reset pulse to the counter after the count therein has been transferred to the register; and g. digital-to-analog converting means (27) for establishing a variable control current whose magnitude is proportional to the count stored in the register.

Claim 3

the latch pulse generator (24) is triggered by a change in the logic voltage from said one level to said other level; and

Claim 4

the latch pulse generator (24) is triggered by a change in the logic voltage from said one level to said other level; and

Claim 5

A telemetric receiver as defined in claim 1 in which the converting means (27) includes a group of ladder resistors (93-102) each of which is connected at one end with one stage of the register (25) and the opposite ends of which are joined by a common conductor (103), the value of each resistor being proportional to 2n x, where n is the number of register stages, and x is the exponent of 2 which determines the positional value of the associated register stage.

Claim 6

A telemetric receiver as defined in claim 2 in which a. the converting means (27) also includes an amplifier (104-113) interposed between each register stage and the associated resistor; and b. including a load resistor (28) connected between said common conductor and a source (42) of constant potential and having a value on the order of one one-hundredth of the value of the smallest ladder resistor, c. each amplifier serving to apply to the associated ladder resistor either a voltage equal to said constant voltage or a predetermined different voltage depending upon which binary digit is stored in the associated register stage.

Claim 7

the reset pulse generator (26) is triggered to supply a pulse to the counter by the trailing end of the latch pulse.

Claim 8

the reset pulse generator (26) is triggered to supply a pulse to the counter by the trailing end of the latch pulse.

Claim 9

A telemetric receiver as defined in claim 1 including a signal loss detector (32) for automatically changing the magnitude of said control current to a predetermined level independent of the count stored in the register whenever the time interval between transmitted signals exceeds a predetermined duration.

Claim 10

A telemetric receiver as defined in claim 4 in which the signal loss detector (32) comprises a. means, including a differentiator (149,151), for producing voltage spikes of opposite polarities at the leading and trailing ends of each transmitted signal; b. a capacitor (152) connected to be charged by only one set of said spikes; c. a resistor (155) connected to provide a discharge path for the capacitor, the time constant provided by the resistor and capacitor being selected to cause the capacitor to discharge to a preselected level in said predetermined duration; and d. means (115,154,156,158) responsive to the charge on the capacitor for reducing the control current to zero whenever the charge on the capacitor is at or below said preselected level.

Claim 11

A telemetric receiver as defined in claim 5 in which a. the capacitor (152) is connected with the differentiator through a blocking diode (153); and b. the means responsive to capacitor charge includes an amplifier (115) and a relay (158) which is energized by the output of the amplifier.

Claim 12

A telemetric receiver as defined in claim 1 including a. a DC power supply (16); and b. a retransmission circuit (33) connected to receive power from said power supply and to create therefrom output signals which correspond to and are synchronized with the transmitted signals.

Claim 13

A telemetric receiver as defined in claim 7 in which the retransmission circuit comprises a. a subcircuit containing a zener diode (163) and a load resistor (162); b. means (16-18) for applying across said subcircuit a DC voltage which is greater than the breakdown voltage of the zener diode when a transmitted signal is being received and which is less than the breakdown voltage in the interval between transmitted signals, whereby a voltage is developed across the load resistor only during the time a transmitted signal is being received; c. a relay (159) includiNg a normally open contact (159a) which selectively connects said DC power supply in a circuit with a pair of output lines (L1); and d. an amplifier (161) controlled by the voltage developed across the load resistor and arranged to energize the relay.

Claim 14

A telemetric receiver as defined in claim 1 including means for changing the frequency of the clock pulses delivered to the counting stages of the counter.

Claim 15

A telemetric receiver as defined in claim 9 in which the means for changing frequency comprises at least one flip-flop frequency divider (79-A or 81-A) which may be selectively interposed in or removed from the path interconnecting the clock pulse generator and the counting stages of the binary counter.

Claim 16

A telemetric receiver as defined in claim 1 in which a. the clock pulse generator (22) includes a rectifier connected with an AC source and having two half-wave rectifying sections (48,49); and b. the clock pulse generator has connections (53) which permit the output of one section or the combined outputs of both sections to be used as the clock pulses.

Claim 17

A telemetric receiver as defined in claim 11 including a. a pair of flip-flop frequency dividers (79-A,81-A); and b. connections (82-85) which permit the clock pulses to be supplied to the counting stages of the counter through a selected one of three paths, namely a direct path which includes neither flip-flop, a second path which includes only one flip-flop, and a third path which includes both flip-flops in series.

Claim 18

A telemetric receiver as defined in claim 12 including connections which permit the clock pulses to be delivered selectively to either the least significant stage or to the next more significant stage of the counter.

Claim 19

A telemetric receiver as defined in claim 1 including a. a readout element (31a) for displaying the information represented by the widths of the transmitted signals; b. a load resistor (28) connected to be traversed by the control current and to develop a control voltage; and c. a servo system (29) which responds to the control voltage and positions the readout element in accordance therewith.

Claim 20

A telemetric receiver as defined in claim 14 in which the servo system includes a. a reversible DC servo motor (121) for positioning the readout element (31a); b. a potentiometer (122) having a wiper (122a) which is positioned by the servo motor and serving to produce a feedback voltage which corresponds to the position of the readout element; c. a first servo amplifier (116) connected to receive the feedback and control voltages and to produce an output whose magnitude is proportional to the difference between said voltages and whose polarity depends upon the relative magnitudes of the two voltages; d. a second servo amplifier (117) connected to amplify the output of the first servo amplifier; e. a power amplifier (118, 119) connected to receive the output of the second servo amplifier and to furnish to the servo motor a proportional drive voltage whose polarity is determined by the polarity of said output; f. a degenerative feedback path extending from the output of the power amplifier to the input of the second servo amplifier and containing an adjustable gain resistor (127); and g. resistance means (144-146) in series with the resistive element of the potentiometer (122) and sized to cause the servo motor to move the indicator full scale for a predetermined change in said control voltage.

Claim 21

A telemetric receiver as defined in claim 1 which includes a. a DC power supply (16) which produces regulated voltages of two levels; and b. means connected with the power supply, and including a line isolation relay (17) which is energized by the transmitted signals, for establishing a logic voltage in an output circuit (18) which corresponds to one of said regulated levels when a transmitted signal is being received and corresponds to the other of said levels in the time interval between transmitted signals; and in which

Claim 22

A telemetric receiver as defined in claim 16 in which both regulated voltage levels are negative, and said one level is the more negative.