Fixturing for pinned transformers
Transformers with vertical pins suitable for conventional “through hole plated” PCB assembly are obviously a large subset of wound magnetic components that are manufactured on a daily basis..
The pin design allows for easy integration with conventional PCB manufacturing, whilst allowing manufacturers to design (and test!) a diverse range of components with similar footprints.
Here are some examples of AT Tester fixturing for typical pinned transformers
The Voltech fixture system allows the tester to be instantly reconfigured for a different bobbin type, and minimizes individual part change over time.
Please click images to zoom
1. Voltech Kelvin Blades
Shown: a Wurth 750811290 SMPS transformer fitted to a Voltech Custom Fixture (91-185) using Kelvin blades.
Ideal for all pinned transformers, where the pin diameter is 0.5-1.0mm
The blade construction of the Kelvin Pin allows for two connections to each pin, thus allowing a true Kelvin connection to the item under test.
This in turn allows the AT Tester to compensate out the effects of the fixtures (natural contact resistance, wire resistance and wire capacitance) from your readings.
Hence you get a true value each and every time.
The blades sit beneath a protective cover plate to protect the blades and simplify location and insertion, giving you a change over time of seconds.
Blade lifetime is in excess of 50,000 insertions.
Below are other examples of a Pulse transformer, Common mode choke, Power factor correction transformer, Power inductor and Audio transformer
2. WILCO Custom Made Fixtures
Our Fixturing partner Wilco Control Service has been providing custom made fixtures for our customers for over 15 years.
They provide a full bespoke turnkey manufacturing service for virtually any transformer type.
Pictured below, is a sample fixture made for the Wurth 750811290.
The fixture block contains 2 rows of Kelvin blades at 5mm pitch, with a row spacing of 25mm.
The transformer shown uses only 9 of the 12 available pins, but as the fixture is fully wired, it can be re-used on ANY transformer with the same pin footprint.
Note also the additional spring probe used for connecting to the core for isolation testing.
Typical cost ~400 USD. Typical life time ; 50,000 tests