for the Church, Academy, and World
The 2021 revision adds a hysteresis resistor network (R7, R8, R9) around the LM339 comparator. This eliminated the "chattering" seen in 2019-2020 models when driving inductive loads (e.g., relays or small motors).
Could you provide the or any other alphanumeric codes printed on the board? This will help pinpoint the exact electronic schematic you need. Hannstar J MV-4 94V-0 Schematic Guide | PDF - Scribd e82152 schematic 2021
