Product Description:

The 21BRCX-607-HG72A is a brushless resolver manufactured by Danaher for the Dynapar Resolvers series. It converts mechanical shaft angle into analog sine and cosine signals that motion controllers interpret for accurate speed and position feedback in industrial drives, packaging machinery, and similar closed-loop automation applications. Its wound stator and laminated rotor withstand heat and vibration in environments where optical encoders may fail, providing a reliable positional reference.

Excitation is applied at 10 kHz, a carrier frequency that reduces low-frequency noise in the recovered position data. The resolver requires a reference voltage of 7 Vrms, so the drive electronics must deliver that amplitude for rated accuracy. With a body length of 1.06 in and an aluminum housing, it fits into tight spaces while providing electromagnetic shielding. A pilot diameter of 2.061 in centers the unit in a motor end bell, and the rotor impedance is 64 Ω, which helps determine the appropriate excitation source. The stator impedance is 49 Ω, while differential Zro and Zso impedances of 145 + j240 Ω and 265 + j485 Ω describe quadrature balance at the rated frequency. Electrical connections use 26 AWG leads that are 12 inches long, allowing the resolver to connect to an input terminal without splicing.

The resolver draws up to 30 mA from the excitation source, keeping power dissipation low in sealed enclosures. At electrical zero, it produces a residual or null voltage of 30 mV, supporting precise mechanical-to-electrical alignment. Signal quadrature has an offset of -8°, and this phase shift is corrected in the resolver-to-digital converter. A transformation ratio of 0.50 provides equal-magnitude sine and cosine outputs, simplifying signal scaling within control loops. A 0.5-inch through-shaft bore supports direct mounting on keyed motor shafts. The twisted conductors help maintain signal isolation between the resolver and the connected drive electronics.