VI conversion - Revision history

Jnc: +cat

2018-12-14T18:42:38Z

+cat

Jnc: clarify, copy-edit

2018-09-28T13:47:25Z

clarify, copy-edit

Jnc: A start - will improve it soon

2018-09-28T01:25:17Z

A start - will improve it soon

New page

'''VI conversion''' (sometimes called '''EI conversion''') is the name for a process used to make [[power supply|power supplies]] efficient.

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. Similarly, a fixed amount of energy at a low voltage means a relatively high current; when converted to high voltage, if the conversion is to be efficient, there must be a lower current.

However, if a power supply takes in a given current (at the supply voltage), and wishes to produce a lower output voltage, then unless it has some way to produce more than that much output current (since otherwise the number of [[electron]]s in the current is fixed, and 'electrons out' must equal 'electrons in'), the voltage difference between the two is lost energy, lowering the efficiency.

An equivalent, but inverse problem is encountered when the output voltage needs to be higher than the input. There are a number of different design approaches that can achieve voltage conversion in an efficient manner.

One approach to VI conversion 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]].

One circuit which can do VI conversion of low current input is a [[buck converter]].

← Older revision		Revision as of 18:42, 14 December 2018
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	[[Switching power supply\|Switching power supplies]] usually have some mechanism to do VI conversion, to allow them to operate with high efficiency.		[[Switching power supply\|Switching power supplies]] usually have some mechanism to do VI conversion, to allow them to operate with high efficiency.
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		+	[[Category: Electrical]]

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 '''VI conversion''' (sometimes called '''EI conversion''') is the name for a process used to make [[power supply|power supplies]] efficient.
-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. Similarly, a fixed amount of energy at a low voltage means a relatively high current; when converted to high voltage, if the conversion is to be efficient, there must be a lower current.
+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 (i.e. low energy loss), there must be a higher current. Similarly, a fixed amount of energy at a low voltage means a relatively high current; when converted to high voltage, if done efficiently, there must be a lower current.
-However, if a power supply takes in a given current (at the supply voltage), and wishes to produce a lower output voltage, then unless it has some way to produce more than that much output current (since otherwise the number of [[electron]]s in the current is fixed, and 'electrons out' must equal 'electrons in'), the voltage difference between the two is lost energy, lowering the efficiency.
+However, if a power supply takes in a given current (at the supply voltage), and wishes to produce a lower output voltage, then unless it has some way to produce more than that much output current. the voltage difference between the two is lost energy, lowering the efficiency. ([[Linear power supply|Linear power spplies]] usually have this issue.) Increasing the current is not trivial, since without some special mechanism, the number of [[electron]]s in the current is fixed, and 'electrons out' must equal 'electrons in'.
-An equivalent, but inverse problem is encountered when the output voltage needs to be higher than the input. There are a number of different design approaches that can achieve voltage conversion in an efficient manner.
+An equivalent, but inverse problem is encountered when the output voltage needs to be higher than the input.
-One approach to VI conversion 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]].
+There are a number of different design approaches which can achieve VI conversion in an efficient manner.
-One circuit which can do VI conversion of low current input is a [[buck converter]].
+One approach is to use a [[transformer]], which can easily turn a high-voltage, low-current input into a low-voltage, high-current output. However, transformers only operate on [[alternating current|AC]].