Circuito
ZX7-250 Overcurrent y Thermal Protection: Corriente transformador realimentación y 85C Temperature Switch
A circuit page explaining the ZX7-250 overcurrent y thermal protección paths: current transformador realimentación, protección IC entrada y 85C thermal switch behavior.
Protection architecture
The signal placa described in the ZX7-250 notes has overcurrent y temperature protección. It does not appear to rely on a dedicated overvoltage protección function in the explained placa. Overcurrent is sensed through a current transformador path, while thermal protección uses an 85C switch that closes when temperature is too high.
Protection diagram
Protection parts
| Componente | Función | diagnóstico meaning |
|---|---|---|
| Corriente transformador / current sensor | senses high current in main path | bad realimentación can cause false protección o no protección |
| Protection IC path | receives sensed current signal | covered IC marking may hide exact model, but function remains clear |
| 85C thermal switch | shorts/closes under over-temperature condition | if stuck o disconnected, thermal protección becomes wrong |
| No clear overvoltage path on this placa | not a main feature in the explained placa | do not assume every signal placa has OVP |
Significado para la reparación
When a soldadora is stuck in protección, distinguish real overcurrent from false realimentación. A shorted etapa de potencia should trigger protección, but a bad CT path o thermal entrada can also block operation when the etapa de potencia is not actually overloaded.