Buck converter - Revision history

Jnc: +cat

2018-12-14T18:45:26Z

+cat

Jnc: Refer to VI conversion article

2018-09-28T01:07:34Z

Refer to VI conversion article

Jnc: tweaks for clarity

2018-09-23T18:03:09Z

tweaks for clarity

Jnc: An OK start

2018-09-23T14:16:02Z

An OK start

New page

A '''buck converter''' is a type of [[circuit]] which allows a [[power supply]] to operate at high efficiency, when converting high-[[voltage]] [[direct current|DC]] to lower voltage.

The problem is that in energy terms, a fixed amount of energy at a high voltage means a relatively low [[current]]; when converted to low voltage, there must be a higher current. However, that requires more [[electron]]s - how can they be produced?

One approach to that problem is to use a [[transformer]], which can turn a high-voltage, low-current input into a low-voltage, high-current output. However, transformers only operate on [[alternating current|AC]].

The buck converter is a solution for DC; it uses an [[inductor]] to store some of the energy in the incoming DC (in the inductor's [[magnetic field]]); once it is fully 'charged', a switch is thrown which cuts off the incoming DC, and in a circuit including the inductor and the load, the collapsing field creates a current which runs around that circuit, using electrons present in the [[conductor]]s.

They are often found in [[switching power supply|switching power supplies]].

==Operation==

The basic actual circuit has a switch, and the inductor, in series in one line from the input to the load; there is also a [[diode]] across the two lines, after the switch.

The switch is closed, and current starts to flow; through the inductor, and through the load. When the voltage across the load is slightly above the desire output voltage, the switch is opened.

The field around the inductor starts to collapse, producing current which flows through the load, and the diode - which is needed to complete a circuit for the newly-'activated' electrons to flow through. (That connection has to be a diode, to prevent current flowing through that path when the switch is closed.)

When the output voltage has dipped slightly below the desired level, the switch is then closed again, and the cycle repeats.

{{semi-stub}}

← Older revision		Revision as of 18:45, 14 December 2018
Line 16:		Line 16:

	{{semi-stub}}		{{semi-stub}}
		+
		+	[[Category: Electronics]]

@@ Line 1: / Line 1: @@
-A '''buck converter''' is a type of [[circuit]] which allows a [[power supply]] to operate at high efficiency, when converting high-[[voltage]] [[direct current|DC]] to lower voltage.
+A '''buck converter''' is a type of [[circuit]] which allows a [[power supply]] to operate at high efficiency, when converting high-[[voltage]] [[direct current|DC]] to lower voltage, the so-called [[VI conversion]] issue.
-The problem is that in energy terms, a fixed amount of energy at a high voltage means a relatively low [[current]]; when converted to low voltage, if the conversion is to be efficient, there must be a higher current. However, that requires more [[electron]]s - how can they be produced?
+The buck converter is a solution for DC; it uses an [[inductor]] to store some of the energy in the incoming DC (in the inductor's [[magnetic field]]); once it is 'charged', a switch is thrown which cuts off the incoming DC, and in a [[circuit]] including the inductor and the load, the collapsing field creates a [[current]] which runs around that circuit, using electrons present in the [[conductor]]s.
 They are often found in [[switching power supply|switching power supplies]].

@@ Line 1: / Line 1: @@
 A '''buck converter''' is a type of [[circuit]] which allows a [[power supply]] to operate at high efficiency, when converting high-[[voltage]] [[direct current|DC]] to lower voltage.
-The problem is that in energy terms, a fixed amount of energy at a high voltage means a relatively low [[current]]; when converted to low voltage, there must be a higher current. However, that requires more [[electron]]s - how can they be produced?
+The problem is that in energy terms, a fixed amount of energy at a high voltage means a relatively low [[current]]; when converted to low voltage, if the conversion is to be efficient, there must be a higher current. However, that requires more [[electron]]s - how can they be produced?
 One approach to that problem is to use a [[transformer]], which can turn a high-voltage, low-current input into a low-voltage, high-current output. However, transformers only operate on [[alternating current|AC]].
-The buck converter is a solution for DC; it uses an [[inductor]] to store some of the energy in the incoming DC (in the inductor's [[magnetic field]]); once it is fully 'charged', a switch is thrown which cuts off the incoming DC, and in a circuit including the inductor and the load, the collapsing field creates a current which runs around that circuit, using electrons present in the [[conductor]]s.
+The buck converter is a solution for DC; it uses an [[inductor]] to store some of the energy in the incoming DC (in the inductor's [[magnetic field]]); once it is 'charged', a switch is thrown which cuts off the incoming DC, and in a circuit including the inductor and the load, the collapsing field creates a current which runs around that circuit, using electrons present in the [[conductor]]s.
 They are often found in [[switching power supply|switching power supplies]].
@@ Line 11: / Line 11: @@
 ==Operation==
-The basic actual circuit has a switch, and the inductor, in series in one line from the input to the load; there is also a [[diode]] across the two lines, after the switch.
+The basic actual circuit has a switch, and the inductor, in series in one line from the input to the load (the other is generally [[ground]]); there is also a [[diode]] across the two lines, after the switch.
-The switch is closed, and current starts to flow; through the inductor, and through the load. When the voltage across the load is slightly above the desire output voltage, the switch is opened.
+The switch is closed, and current starts to flow; through the inductor, and through the load. When the voltage across the load is slightly above the desired output voltage, the switch is opened.
 The field around the inductor starts to collapse, producing current which flows through the load, and the diode - which is needed to complete a circuit for the newly-'activated' electrons to flow through. (That connection has to be a diode, to prevent current flowing through that path when the switch is closed.)