Isolated Vs Non Isolated Power Supply

This is a lesson usually learned on the road when the guitar player is doing a live performance and has a bad experience with a non isolated ps many of us have a story like this that ends with buying a new isolated supply.

Isolated vs non isolated power supply.

The down side is there is no isolation between the input and output. Non isolated power supplies are commonly board mounted near the load they are driving and are referred to as point of load pol power supplies. First you ll enjoy more board space relative to an isolated power supply design due to the fact that you won t need to put a big transformer in your enclosure. An isolated converter provides isolation between the input and output voltage usually with a transformer.

However more pedals pulling power from the same source increases the capacitive load on the power supply which can result in one or more pedals being noisier than usual depending on the pedals in use. Non isolated supplies always hold the risk of electrical shock through the design. The cost adding components mentioned previously take up more space than those used in a non isolated design. Non isolated converters tend to be smaller than isolated.

You ll also benefit from increased efficiency with a non isolated power supply. In the non isolated converter there is a dc path from input to output. For some single examples it is required to have isolated power supply for phone chargers or laptop adaptors which is directly plug in to the wall with high voltage. In addition to substituting an inductor for a transformer non isolated converters tend to operate at higher switching frequencies which will further reduce the size of the magnetic components and capacitors.

In most cases this works fine. Isolation describes the electrical separation between the input and output of a dc dc converter. However some applications require isolation between the input and output voltages. While the isolated power supplies tend to be a more substantial investment they offer more peace of mind and more reliable service.

Non isolated power supplies for guitar pedals are basically one power source that a number of different pedals can draw from often in daisy chain fashion. For some applications non isolated converters are appropriate.