Whether you are designing or servicing an electronics system, you know that the transformer is often the heaviest, bulkiest and (yes!) costliest item on your panel.
Can I just do without it? Unfortunately, no.
So how do I choose the optimum transformer for my electronics system?
Transformers on electronic panels fall into roughly two categories
Step-down transformers
Isolation transformers
Step-down transformers are used to convert the input supply voltage (approx. 230V or 110V, depending on where you live) to the voltages required by your electronic components – usually in the range of 5V to 24V. They operate at the supply frequency of 50Hz or 60Hz. Some specialized applications such as aircraft systems operate at 400Hz. Every electronics system will have at least one step-down transformer.
Electronics isolation transformers are sometimes necessary. Generally, they do not vary the voltage but operate on a wide range of frequencies such as 10kHz to 100kHz. They are smaller and lighter than step-down transformers. We will not be discussing them today. Some factors to consider when choosing an electronics step-down transformer
Single input or multiple inputs
If your system is going to be used only in one country, say India, then a single input channel of 230V is sufficient for most applications. Occasionally, you may require a transformer that can also operate at a lower input voltage, say 200V, or higher input voltage, say 240V. You may also require that your system operate internationally, in countries where the supply voltage is only 110V.
Multiple input taps can be provided by manufacturers based on your application requirements – however care must be taken during the design process, so that the transformer can withstand increased current loads caused by lower voltages. Our experienced team can help you with that.
Transformer AC output to system DC input
Transformer outputs are generally stated as AC RMS Voltages, whereas your system requirements are usually DC Voltages. Communication gaps can cause you to end up with a transformer that provides insufficient voltage to power your systems, so care must be taken. The conversion factor depends on the type of rectification used, and the number of phases. We welcome your queries so that there are no nasty surprises after installation.
One transformer or many
Multiple outputs from a transformer are a mixed blessing. Multiple channels can power multiple components from one transformer, but increasing the load on the transformer increases its size too. Height of the transformer is generally the limiting factor, so double check the transformer data sheet to ensure it can fit into your system.
If there is no possibility of lowering the transformer height, then consider splitting the load between two or even three smaller transformers. You can talk to us anytime about sizing and alternate options.
Positioning and cooling
Once you’ve chosen the optimum transformer, it is also essential that it’s positioned to give you maximum life and value. While industrial transformers commonly fail due to current overloads, failure of electronics transformers are commonly caused by overheating.
To prevent transformer overheating, ensure it receives airflow from the system’s cooling fan without any obstruction. When positioning other components, prioritize sufficient air gap around the transformer. Remember that a little care reaps long-term savings in maintenance and replacement costs.
Fan-cooling not possible? You can talk to us about rugged transformers that can withstand higher levels of heating.
See our range of standard electronics transformers contact us with your custom requirements