DC-DC
DC-to-DC converter
A DC/DC converter changes a documented DC input into another DC output.
SLD / Schematic
Symbols · DC/DC ISO
Isolated DC-to-DC converter
A DC/DC converter with an internal high-frequency transformer that separates input and output galvanically.
In plain English
What does Isolated DC-to-DC converter mean?
An isolated DC/DC converter uses a high-frequency transformer between its input and output stages, so the two DC systems have no conductive connection. Isolation lets the output be earthed differently from the input, for example a floating battery bus supplying an earthed control system, or keeps a fault on one side from reaching the other.
A simple example
Drawings show the DC/DC box with a transformer mark or a pair of coupled coils inside, or a vertical double line across the box. The isolation voltage is a key rating and should be written beside it.
What the drawings help you do
The symbol alone does not state the test voltage or whether the isolation is functional or reinforced for safety. Those properties decide whether the output can be treated as a separated circuit, so they must be read from the product data.
This particular reference
A DC/DC converter with an internal high-frequency transformer that separates input and output galvanically. An isolated converter separates input and output; a non-isolated buck or boost converter shares a common conductor.
- DC
- Direct current: electricity flowing in one direction.
- Winding
- A coil of conductor inside an electrical machine or transformer.
- Normally open / normally closed
- The contact state in the normal condition defined for the drawing.
Read the source: Power topology selection and public topology tutorials · DIN-rail power supply, buffer, redundancy and UPS families
SLD / Schematic · DC/DC ISO
What it represents
An isolated DC/DC converter uses a high-frequency transformer between its input and output stages, so the two DC systems have no conductive connection. Isolation lets the output be earthed differently from the input, for example a floating battery bus supplying an earthed control system, or keeps a fault on one side from reaching the other.
Drawings show the DC/DC box with a transformer mark or a pair of coupled coils inside, or a vertical double line across the box. The isolation voltage is a key rating and should be written beside it.
The symbol alone does not state the test voltage or whether the isolation is functional or reinforced for safety. Those properties decide whether the output can be treated as a separated circuit, so they must be read from the product data.
How to read it
- A transformer mark inside the box shows isolation.
- Read the isolation rating rather than assuming safety separation.
Information to show or reference
- State input and output voltages and isolation voltage.
- Show earthing on each side.
- Reference isolation class.
A distinction that matters
An isolated converter separates input and output; a non-isolated buck or boost converter shares a common conductor.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Power topology selection and public topology tutorials
Public power topology tutorials including isolated converters.
DIN-rail power supply, buffer, redundancy and UPS families
Public DC power supply and converter family context.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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