The inductive collector ring, also known as a rotary transformer type or contactless collector ring. Its working principle is to use electromagnetic induction to transmit the measurement electrical signals from the rotating part to the fixed part, eliminating various contact points, so there are no issues such as contact resistance.
The electrical schematic and structure of this collector ring are shown in the right figure. The four strain gauges attached to the measured shaft are connected in a full-bridge circuit; the bridge supply voltage of the strain gauge
is supplied through the input transformer
to the input terminals A and C of the bridge. The output signal of the bridge
is output from terminals B and D through the output transformer
. The secondary winding of transformer
and the primary winding of transformer
and transformer
are fixed on the inner sleeve l of the collector ring and rotate together with the measured shaft. The primary winding of transformer
