The present disclosure relates to the field of regulated power
supply. More particularly the present disclosure relates to a regulated power supply with switched Zener diode.
BACKGROUND
[0002] Background description includes information that may be useful in
understanding the present invention. It is not an admission that any of the
information provided herein is prior art or relevant to the presently claimed
invention, or that any publication specifically or implicitly referenced is prior art.
[0003] In embedded products there is a possibility of wide range of
voltage at the Input of the power supply unit. While designing power supply of the product these ranges to be handled. The output voltage of the power supply block should remain fixed whereas Input voltage will vary based on the number of phases present or range of supply voltage available in the input side. In the power supply design Zener Diode is used as voltage regulator. In the product, load current remains fixed and the design should support this load current. The power supply design should be capable to drive the load with lower input voltage at the input terminal to the higher input voltage available at the input with the selected Zener device. For example, to support single phase 144V at the input side higher Zener value to be selected whereas for 3 phase 288V at the input, lower voltage Zener diode is enough to drive the load. With this type of products, the problem is power dissipation across Zener. Power dissipation is more if higher voltage is present at the input terminal. The Zener can heat up which will reduce the reliability of the product. With the present solution we can manage the heating issue and increase the reliability.
[0004] There is, therefore, a need of an improved regulated power supply
that is free from above discussed problems.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] Some of the objects of the present disclosure, which at least one
embodiment herein satisfies are as listed herein below.
[0006] It is an object of the present disclosure to provide a regulated
power supply, which has less power dissipation across Zener diode.
[0007] It is an object of the present disclosure to provide a regulated
power supply, which has improved reliability.
[0008] It is an object of the present disclosure to provide a regulated
power supply, which has increased life.
[0009] It is an object of the present disclosure to provide a regulated
power supply, which is cost effective.
[0010] It is an object of the present disclosure to provide a regulated
power supply, which is efficient.
SUMMARY
[0011] The present disclosure relates to the field of regulated power
supply. More particularly the present disclosure relates to a regulated power supply with switched Zener diode.
[0012] An aspect of the present disclosure pertains to a regulated voltage
power supply that includes a rectifier electrically coupled to an input supply for
converting an AC voltage into a DC voltage. A voltage regulator electrically
coupled with the rectifier to regulate the DC voltage output of the rectifier. The
voltage regulator includes a first Zener diode, and a second Zener diode serially
coupled with the first Zener diode. A DC-DC voltage converter electrically
coupled, in parallel, with the voltage regulator. A switch electrically coupled
between the serially coupled first Zener diode and the second Zener diode,
wherein the switch is operatively configured with the input supply.
[0013] In an aspect, the switch may be electrically open when the input
supply is a single-phase power.
[0014] In an aspect, the switch may be electrically closed, such that the
Zener diode is inactive, when the input supply is a three-phase power.

[0015] In an aspect, rectifier may be electrically coupled with the input
supply through a series impedance capacitor.
[0016] Various objects, features, aspects and advantages of the inventive
subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF DRAWINGS
[0017] The accompanying drawings are included to provide a further
understanding of the present disclosure, and are incorporated in and constitute a
part of this specification. The drawings illustrate exemplary embodiments of the
present disclosure and, together with the description, serve to explain the
principles of the present disclosure. The diagrams are for illustration only, which
thus is not a limitation of the present disclosure.
[0018] In the figures, similar components and/or features may have the
same reference label. Further, various components of the same type may be
distinguished by following the reference label with a second label that
distinguishes among the similar components. If only the first reference label is
used in the specification, the description is applicable to any one of the similar
components having the same first reference label irrespective of the second
reference label.
[0019] FIG. 1 illustrates exemplary representation of a regulated power
supply, in accordance with an embodiment of the present disclosure.
[0020] FIG. 2A illustrates exemplary representation of the regulated
power supply in case of single-phase input and FIG. 2B illustrates exemplary
representation of the regulated power supply in case of three-phase input, in
accordance with an embodiment of the present disclosure.
[0021] FIG. 3 A illustrates an exemplary representation of control circuitry
and FIG. 3B illustrates an exemplary method for detection of single phase or
multiphase input voltage.

DETAILED DESCRIPTION
[0022] The following is a detailed description of embodiments of the
disclosure depicted in the accompanying drawings. The embodiments are in such
detail as to clearly communicate the disclosure. However, the amount of detail
offered is not intended to limit the anticipated variations of embodiments; on the
contrary, the intention is to cover all modifications, equivalents, and alternatives
falling within the scope of the present disclosure as defined by the appended
claims.
[0023] In the following description, numerous specific details are set forth
in order to provide a thorough understanding of embodiments of the present
invention. It will be apparent to one skilled in the art that embodiments of the
present invention may be practiced without some of these specific details.
[0024] The present disclosure relates to the field of regulated power
supply. More particularly the present disclosure relates to a regulated power
supply with switched Zener diode.
[0025] The present disclosure elaborates upon a regulated voltage power
supply that includes a rectifier electrically coupled to an input supply for
converting an AC voltage into a DC voltage. A voltage regulator electrically
coupled with the rectifier to regulate the DC voltage output of the rectifier. The
voltage regulator includes a first Zener diode, and a second Zener diode serially
coupled with the first Zener diode. A DC-DC voltage converter electrically
coupled, in parallel, with the voltage regulator. A switch electrically coupled
between the serially coupled first Zener diode and the second Zener diode,
wherein the switch is operatively configured with the input supply.
[0026] In an embodiment, the switch can be electrically open when the
input supply is a single-phase power.
[0027] In an embodiment, the switch can be electrically closed, such that
the Zener diode is inactive, when the input supply is a three-phase power.
[0028] In an embodiment, rectifier can be electrically coupled with the
input supply through a series impedance capacitor.

[0029] FIG. 1 illustrates exemplary representation of a regulated power
supply, in accordance with an embodiment of the present disclosure.
[0030] FIG. 2A illustrates exemplary representation of the regulated
power supply in case of single-phase input and FIG. 2B illustrates exemplary representation of the regulated power supply in case of three-phase input, in accordance with an embodiment of the present disclosure.
[0031] FIG. 3 A illustrates an exemplary representation of control circuitry
and FIG. 3B illustrates an exemplary method for detection of single phase or multiphase input voltage.
[0032] As illustrated, a regulated voltage power supply 100 can include a
rectifier 104 that can be electrically coupled to an input supply 102. The rectifier can convert an AC voltage into a DC voltage and can include any of a half wave rectifier, a full wave rectifier, and a bridge rectifier. A voltage regulator 106 can be electrically coupled with the rectifier 104 to regulate the DC voltage output of the rectifier 104. The voltage regulator can include a series combination of a first Zener diode 106-1, and a second Zener diode 106-1. A DC-DC voltage converter 108 can be electrically coupled, in parallel, with the voltage regulator 106. The rectifier 104 can be electrically coupled with the input supply through a capacitor 112.
[0033] In an embodiment, a switch 110 can be electrically coupled
between the serially coupled first Zener diode 106-1 and the second Zener diode 106-2, and the switch 110 is operatively configured with the input supply through a control circuitry 114. A GPIO pin of a processor can be used as control circuit which can be configured through firmware logic. Additionally, Operational amplifier can also be used to control the switch 110 which has input voltage as one input and reference voltage as second input with high or low output. The switch can include but not limited to a MOSFET. The switch 110 can be electrically open when the input supply is a single-phase power. The input supply can be sensed using firmware logic. Using ADC, voltage can be measured and identified whether single phase is present at the input side or more phases are present (FIG. 3B). Then based on this the processor (or microcontroller) can be

used to control the switch. Electrically open can be referred to when an end of the switch is electrically decoupled with a ground terminal of the input supply. The switch 110 can be electrically closed, such that the second Zener diode 106-2 is inactive, when the input supply is a three-phase power. Electrically close can be referred to when an end of the switch is electrically coupled with the ground terminal of the input supply.
[0034] The present disclosure pertains to a power supply circuit having
two serially connected Zener diodes for the voltage regulation purpose. When the input supply is single phase both of the two Zener diodes can conduct because power dissipation across the Zener diode is reduced since a current following through a conducting Zener diode is less. When the input supply is three-phase one of the Zener diodes can conduct to reduce power dissipation across the Zener diode since a current following through a conducting Zener diode is less. In both the cases the load current remains same.
[0035] Moreover, in interpreting the specification, all terms should be
interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ....and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[0036] While the foregoing describes various embodiments of the
invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0037] The proposed invention provides a regulated power supply, which
has less power dissipation across Zener diode.
[0038] The proposed invention provides a regulated power supply, which
has improved reliability.
[0039] The proposed invention provides a regulated power supply, which
has increased life.
[0040] The proposed invention provides a regulated power supply, which
is cost effective.
[0041] The proposed invention provides a regulated power supply, which
is efficient.

We Claim:

1. A voltage regulated power supply comprising:
a rectifier electrically coupled to an input supply for converting an AC voltage into a DC voltage;
a voltage regulator electrically coupled with the rectifier to regulate the DC voltage output of the rectifier, wherein the voltage regulator comprises a first Zener diode, and a second Zener diode serially coupled with the first Zener diode;
a DC-DC voltage converter electrically coupled, in parallel, with the voltage regulator; and
a switch electrically coupled between the serially coupled first Zener diode and the second Zener diode, wherein the switch is operatively configured with the input supply.
2. The power supply as claimed in claim 1, wherein the switch is electrically open when the input supply is a single-phase power.
3. The power supply as claimed in claim 1, wherein the switch is electrically closed, such that the Zener diode is inactive, when the input supply is a three-phase power.
4. The power supply as claimed in claim 1, wherein rectifier is electrically coupled with the input supply through a capacitor.