Whirlpool LSN1000JQ0 Timer Replacement Project

This project aims to replace the original electromechanical timer (Part No. WP3953317) of a Whirlpool LSN1000JQ0 washing machine with a modern electronic controller.

Analysis of Original Timer (3954584 REV A)

The original timer is an electromechanical device that uses a synchronous motor to turn a camshaft, which in turn activates several switches in a specific sequence.

Key Components to Control

1. Drive Motor (661600):
   • Supports High (HI) and Low (LO) speeds.
   • Includes a Start winding, Run windings, and a centrifugal switch.
   • Directional control for Agitation vs. Spin is inherent to the motor's design and wiring.
2. Water Valves:
   • Hot and Cold water solenoids.
   • Controlled via the Water Temp Switch, but powered through the timer.
3. Buzzer:
   • End-of-cycle signal.
4. Timer Motor:
   • Originally advances the mechanical clock.

Inputs/Sensors to Monitor

1. Water Level (Pressure) Switch:
   • Provides "FULL" and "EMPTY" signals.
2. Lid Switch:
   • Safety cutoff for spin/agitation.
3. Water Temp Switch:
   • User selection for wash/rinse temperature.

Timing Logic

• The original timer operates at 180 seconds per step.
• The cycle consists of multiple steps: Fill, Agitate, Drain, Spin, Spray Rinse.
• Different cycles (Heavy, Regular, Permanent Press, Delicate/Hand Wash) start at different points on the timer dial.

Requirements for Electronic Replacement

To replicate the functionality, the replacement system must provide:

Hardware Requirements

• Microcontroller: (e.g., ESP32, Arduino, or similar) to manage timing and logic.
• Power Supply: 5V/12V DC for the microcontroller and relay coils.
• Output Switching:
  • 6-8 Relays or Triacs capable of handling 120V AC at 10A+ (for the motor).
  • Relays for Water Valves and Buzzer.
• Inputs:
  • Optoisolators or voltage dividers to safely sense 120V AC signals from the Water Level Switch and Lid Switch.
  • A user interface (buttons, rotary encoder, or Wi-Fi/Web interface) to select cycles.
• Safety: Must maintain the lid switch safety logic and prevent simultaneous activation of conflicting motor windings.

Software Requirements

• Cycle State Machine: A robust state machine to track the current phase of the wash cycle.
• Step Timing: Precise timing to match or improve upon the original 180s/step logic.
• Safety Interlocks: Code-level checks to ensure the lid is closed during dangerous operations (Spin) and that the motor isn't stalled.

Wiring Reference (from IMG_20260314_175414.jpg)

• Switch 2: Lid Switch integration.
• Switch 6/8: High Speed Motor.
• Switch 10: Low Speed Motor / Main Power.
• Switch 12/14: Motor Start / Centrifugal Switch logic.
• Switch 11/13: Water Fill / Spray Rinse.
• Switch 48: Intermittent Agitation (specific to Delicate/Hand Wash cycles).
• Sub-Interval Pattern: Used for pulsed operations like Spray or Intermittent Agitation.