Spark Logic

EC11E quadrature rotary encoder connection guide

EC11E quadrature rotary encoder EC11E with push switch wiring guide with power, signal assignments, and bench checks.

EC11E without push switch 5 contacts

EC11E with push switch

5 contacts Current package

Alps Alpine · Three rotation contacts and two isolated push-switch terminals.

18 detents, 9 pulses per revolution, 1.5 mm switch travel.

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.

Connection scenarios

Read the shaft push switch

Connect E to ground and D to a 5 V-tolerant input. Pull D up through 4.7 kΩ. Keep the rotation contacts wired independently.

  • 5 V logic
    • Regulated 5 V
    • RA.1
    • RB.1
    • RS.1
  • Ground
  • Phase A
    • A (A)
    • Controller input A
    • RA.2
    • CA.1
  • Phase B
    • B (B)
    • Controller input B
    • RB.2
    • CB.1
  • Push input
    • D (D)
    • Controller push input
    • RS.2
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
RS 4.7 kΩ between 5 V logic and Push input5 V logicRS 4.7 kΩPush input

Bench checks

  • Check high when released and low when pressed. Debounce the push input independently of the phase decoder.

Alps Alpine EC11E catalog, drawings 1–3, switch symbol in drawings 2–3.

EC11E with push switch wiring map

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

EC11E with push switch
Catalog mounting-side view. The two switch terminals sit opposite the A, C, B row. Scroll the map to reach all contacts.
Selected pin details

A · A

Contact · Outputs

Phase A switch contact. Pull up through an external resistor.

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.

EC11E09244BS
18 detents, 9 pulses per revolution, 0.5 mm switch travel.
EC11E15244G1
30 detents, 15 pulses per revolution, 0.5 mm switch travel.
EC11E18244AU
36 detents, 18 pulses per revolution, 0.5 mm switch travel.
EC11E09244AQ
18 detents, 9 pulses per revolution, 1.5 mm switch travel.
EC11E15244B2
30 detents, 15 pulses per revolution, 1.5 mm switch travel.
EC11E18244A5
36 detents, 18 pulses per revolution, 1.5 mm switch travel.