Transformers and Inductors pricing

Thread Starter

PE_enthusiast

Joined Mar 19, 2024
1
Hello all,
On what factors does the price of custom magnetics ( mainly transformer, inductor ( PFC boost , common mode and differential mode chokes) depends on?
For example shapes of the ferrite core, size of the core, amount of windings, maximum power ( in watts).From a cost perspective is an integrated transformer (LLC) better compared to transformer + resonant inductor?
Thank you !
 

ronsimpson

Joined Oct 7, 2019
3,145
Too many questions to answer but I will try.
Price has to do with volume. Example: My last inductor took me 1 day to design it, 1 day to make the tooling for the winding machines and some time to order 10 sets of parts. The shipping costs more than the parts did. So the first part cost me $2000 usd out of my pocket. Some companies will make the first parts for free and some age going to charge time and materials.

When you order 1000 parts the shipping is only a small part of the total price and labor is maybe 1 day to make all 1000. The tooling is free. Making a million is done in China at a very low labor rate.

Cost of cores. EI and EE cores are low cost. POT cores are high cost. Very small cores are hard to make.
If possible use products that are in production. Not special parts.
I am not offering to make these. Just saying what I know.
 
Last edited:

UweX

Joined Sep 2, 2020
33
I fully agree to the above. Just another point to mention: are you planing to build a line-voltage supplied power supply ?
In that case you also have to take in to account that the construction of the transformer follows the rules from UL, VDE or the safety-related organization in you country. So getting the approval for a transformer is some additional cost for the supplier and therefore finally you. So I recommend to separate transformer and inductor and you may be lucky in case you find a standard part for both components.
And generally speaking: The price depends on your requirements. So you define nominal inductance, transfer ratio, nominal and peak current in the windings, wire resistance (determines self heating and efficiency), operating frequency ( there are a lot of different ferrite materials around, each optimized for something specific) operating temperature range and so on.
From these numbers you can look for the right component at the suppliers mentioned above.
 

Ian0

Joined Aug 7, 2020
10,044
For a LLC supply, the series inductance is achieved as leakage inductance in the transformer. That allows the use of two-section bobbins which makes compliance with safety regulations MUCH easier.
However, it may mean that you need Litz wire for the secondary.
 

wpri268

Joined Feb 18, 2012
31
Hello all,
On what factors does the price of custom magnetics ( mainly transformer, inductor ( PFC boost , common mode and differential mode chokes) depends on?
For example shapes of the ferrite core, size of the core, amount of windings, maximum power ( in watts).From a cost perspective is an integrated transformer (LLC) better compared to transformer + resonant inductor?
Thank you !
Hello all,
On what factors does the price of custom magnetics ( mainly transformer, inductor ( PFC boost , common mode and differential mode chokes) depends on?
For example shapes of the ferrite core, size of the core, amount of windings, maximum power ( in watts).From a cost perspective is an integrated transformer (LLC) better compared to transformer + resonant inductor?
Thank you !
Cost of magnetics depends on two basic items. First is material cost which includes core, coil former, magnet wire, insulation, varnish and any hardware. Second is the manufacturing cost that includes coil winding machine set-up, winding, transformer assembly, as well as treatment, testing, handling, and shipping. Volume greatly affects per unit cost with prototypes being the most expensive.
 

Johnfoxwell

Joined May 23, 2021
17
Always design around what is available. Having custom inductors and transformers make maintenance difficult. Realise that your design is probably not that unique.
 
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