# US 2022/0045677 A1 · Circuitry for providing digitally stable ground

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- Number: US 2022/0045677 A1
- Document ID: US20220045677A1
- Status: Published application
- Kind: A1
- Application number: 17/510,153
- Filed: 2021-10-25
- Published: 2022-02-10
- Earliest claimed: 2018-09-12
- Assignees: Ubicquia, Inc.
- Applicants: Ubicquia, Inc.
- Inventors: Bradford Brian Hutson; Ronald B. Zimmerman, III; Ian B. Aaron; Yevgeny Frenkel
- Web page: https://patentgrep.com/patent/US20220045677A1

## CPC

- H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop}
- H03K 17/61: using transformer coupling
- G06F 1/26: Power supply means, e.g. regulation thereof (for memories G11C)
- G06F 1/3206: Monitoring of events, devices or parameters that trigger a change in power modality
- H02M 1/081: {wherein the phase of the control voltage is adjustable with reference to the AC source}
- H04B 3/54: Systems for transmission via power distribution lines
- H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
- H05B 47/11: by determining the brightness or colour temperature of ambient light
- H05B 47/19: via wireless transmission
- H02M 1/123: {Suppression of common mode voltage or current}
- H02M 1/32: Means for protecting converters other than automatic disconnection
- H02M 1/348: {Passive dissipative snubbers}
- H05B 45/385: using flyback topology
- H05B 47/1965: {using handheld communication devices}
- H05B 47/26: Circuit arrangements for protecting against earth faults
- Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- H04B: TRANSMISSION
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A small cell networking device mountable to a streetlight fixture includes circuitry for converting alternating current power into direct current (DC) power and providing a digitally stable ground for operation of the small cell device. The circuitry includes a transformer isolating a primary side from a secondary side of the circuitry. A switching controller on the primary side directs a switching circuit to selectively permit current flow through a primary side of the transformer to a first ground node on the primary side. A secondary winding of the transformer sources a rectified DC output relative to a second ground node that is isolated from the first ground node. In some cases, compensation on the secondary winding side provides isolated feedback to the controller, such as via an optical isolator. The controller directs the switching circuit based at least on the feedback and input from an auxiliary winding of the transformer.

## Claims

### Claim 1

A small cell networking device comprising:
a networking module arranged as a gateway to a cellular-based network, the cellular-based network controlled by a mobile network operator (MNO);
a light sensor;
a processor-based light control circuit arranged to provide a light control signal based on at least one ambient light signal generated by the light sensor;
a connector compliant with a roadway area lighting standard promoted by a standards body, the connector including a set of connector elements that interface with corresponding receptacle elements of a receptacle of a streetlight fixture;
first circuitry to detect a stray voltage between a housing of the small-cell networking device and a neutral power line signal passed through the connector; and
second circuitry to convert alternating current (AC) mains power received at the connector into direct current (DC) power and to provide a digitally stable ground, the second circuitry including:
a pair of circuitry inputs, a first input of the pair of inputs being connected to a first connector element of the set of connector elements, and a second input of the pair of inputs being connected to a second connector element of the set of connector elements;
a first ground node and a second ground node galvanically isolated from the first ground node;
a transformer that galvanically isolates the first ground node from the second ground node, the transformer including a primary winding, a secondary winding coupled to the second ground node, and an auxiliary winding coupled to the first ground node;
a first set of electrical components for providing filtered and rectified power to the primary winding;
a solid-state switching device connected between the primary winding and the first ground node;
a pulse width modulation (PWM) controller that controls switching of the solid-state switching device, the PWM controller powered by power received from the auxiliary winding and coupled to the first ground node;
an output capacitor and a diode coupled to the secondary winding and providing a DC voltage output relative to the second ground node;
an error compensation subcircuit that provides an error signal based at least in part on the DC voltage output, the error compensation subcircuit coupled to the second ground node;
an optical isolator that provides a feedback signal to the PWM controller based at least in part on the error signal;
a DC output node; and
a digitally stable ground galvanically isolated from a mains power ground node.

### Claim 2 (depends on 1)

The small cell networking device of claim 1, wherein an alert generated in response to a detected stray voltage is communicated to a remote computing device via a cellular-based protocol.

### Claim 3 (depends on 1)

The small cell networking device of claim 1, wherein the connector is compliant with American National Standards Institute (ANSI) C136.

### Claim 4

A small cell networking device mountable to a streetlight fixture that includes a receptacle and a luminaire, the small cell networking device comprising:
a housing;
a networking module located within the housing and operable as a gateway to a cellular-based network;
a light sensor;
a processor-based light control circuit operable to provide a light control signal for controlling operation of the luminaire based on an output of the light sensor;
a connector accessible from an exterior of the housing, the connector including a set of connector elements that are interfaceable with corresponding receptacle elements of the receptacle of the streetlight fixture;
first circuitry operable to detect a stray voltage between the housing and a neutral power line signal passed through the connector; and
second circuitry operable to convert alternating current power received at the connector into direct current (DC) power and provide a digitally stable ground, the second circuitry including:
a pair of inputs, a first input of the pair of inputs being connected to a first connector element of the set of connector elements, and a second input of the pair of inputs being connected to a second connector element of the set of connector elements;
a first ground node;
a second ground node;
a transformer that galvanically isolates the first ground node from the second ground node, the transformer including a primary winding, a secondary winding coupled to the second ground node, and an auxiliary winding coupled to the first ground node;
a first set of electrical components that provide filtered and rectified power to the primary winding of the transformer;
a switching device connected between the primary winding of the transformer and the first ground node;
a switching controller that controls switching of the switching device, the switching controller being powered by power received from the auxiliary winding of the transformer and coupled to the first ground node;
an output capacitor and a diode coupled to the secondary winding of the transformer and providing a DC voltage output relative to the second ground node;
an error compensation subcircuit that provides an error signal based at least in part on the DC voltage output, the error compensation subcircuit being coupled to the second ground node; and
an optical isolator that provides a feedback signal to the switching controller based at least in part on the error signal.

### Claim 5 (depends on 4)

The small cell networking device of claim 4, wherein the switching controller is a pulse width modulation controller.

### Claim 6 (depends on 4)

The small cell networking device of claim 4, wherein the switching device is a solid-state switching device.

### Claim 7 (depends on 4)

The small cell networking device of claim 4, wherein the second circuitry further includes:
a DC output node, wherein the digitally stable ground is galvanically isolated from a mains power ground node.

### Claim 8 (depends on 4)

The small cell networking device of claim 4, wherein an alert generated in response to a detected stray voltage is communicated to a remote computing device via a cellular-based protocol.

### Claim 9 (depends on 4)

The small cell networking device of claim 4, wherein the connector is compliant with a roadway area lighting standard promoted by a standards body.

### Claim 10 (depends on 4)

The small cell networking device of claim 4, wherein the second connector element is electrically coupled to the first ground node.