Spark Logic

EC11E quadrature rotary encoder connection guide

EC11E quadrature rotary encoder EC11E without push switch wiring guide with power, signal assignments, and bench checks.

EC11E without push switch

5 contacts Current package
EC11E with push switch 5 contacts

Alps Alpine · 11 mm body with three electrical terminals and two dummy terminals.

18 detents, 9 pulses per revolution, no push switch.

Observe the two rotation phases

Required

Use 5 V-tolerant inputs. Connect C to ground and fit one 4.7 kΩ pull-up and one 10 nF capacitor on each phase. Turn the shaft slowly while monitoring both lines.

  • 5 V logic
    • Regulated 5 V
    • RA.1
    • RB.1
  • Ground
    • C (C)
    • Controller ground
    • CA.2
    • CB.2
  • Phase A
    • A (A)
    • Controller input A
    • RA.2
    • CA.1
  • Phase B
    • B (B)
    • Controller input B
    • RB.2
    • CB.1
RA 4.7 kΩ between 5 V logic and Phase A5 V logicRA 4.7 kΩPhase A
RB 4.7 kΩ between 5 V logic and Phase B5 V logicRB 4.7 kΩPhase B
CA 10 nF between Phase A and GroundPhase ACA 10 nFGround
CB 10 nF between Phase B and GroundPhase BCB 10 nFGround

Bench checks

  • When closed, each contact carries about 1.06 mA. The closed phase should read near ground.
  • Check the transition order in both directions. Contact bounce is much longer than the RC time constant, so debounce or reject invalid transitions in firmware.

Alps Alpine EC11E catalog, drawings 1–3, Output Wave and Cautions. Pull-ups are chosen to meet the minimum specified contact current.

EC11E without push switch wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

EC11E without push switch
Catalog mounting-side view. The two dummy terminals sit opposite the A, C, B row. Scroll the map to reach all contacts.
Selected pin details

B · B

Contact · Outputs

Phase B switch contact. Its transitions are offset from phase A.

Alps Alpine EC11E catalog, drawings 1–3

Electrical limits · Pin in the reference

Models and documents

These maps cover the flat-shaft EC11E variants listed by Alps Alpine. The drawings identify mechanical support tabs and dummy terminals separately.

EC11E09204A4
18 detents, 9 pulses per revolution, no push switch.
EC11E15204A3
30 detents, 15 pulses per revolution, no push switch.
EC11E1820402
36 detents, 18 pulses per revolution, no push switch.