Coil Ring Tester Attachment Now Available

// September 4th, 2020 // Uncategorized

Siborg has begun offering a new Coil Ring Tester for LCR-Reader-MPA.

LCR-reader-MPA with Coil Ring Tester

The main difficulty for testing coils if that the LCR-meter shows almost no change in the impedance value if there is a short turn in the coil. An accurate way of finding short turns in a coil is by using the Ring Test technique. This method has been used in old AV equipment that us flybacks, motors, chopper transformers, deflection yoke windings, magnetic heads, main transformers and ore.

The coil ring method is based on Gibbs phenomenon that is a response of the system to a step excitation. When a capacitor is connected across the investigated coil and a pulse is applied to the parallel circuit. The wave form across the resonant circuit will create a decaying oscillation, with at least a few cycles if the coil is good. The oscillations will be strongly damped and only complete one or two cycles if there is a shorted turn in any of the magnetically coupled coils of the device. A short turn could also be applied, when applicable, to compare with and without a short turn. If there is no change, there is a short turn in at least one coil. Experience and comparison with a known good device will tell you what to expect.

The LCR-Reader-MPA is connected to the Ring tester using the micro-USB plug and connected to the coil under test using the hook connectors. Set the MPA to “winding turns” in the menu. When the device is set, the screen will show the response on the display. The example below shows a dramatic difference; when a shorted turn is connected, the display shows significantly higher dissipation factor and therefore a fewer number of oscillations following the impulse on the coil.

Coil Ring Tester with LCR-Reader-MPA

The Ring Coil Tester Attachment is currently only available from Siborg directly and from their Chinese distributor AI-Rox in Shenzhen.

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