Circuit
ZX7-250 220V / 380V Relay Boost and DC Bus: Dual Bridge Rectifier to 530-560V
A circuit page explaining the ZX7-250 input stage: dual bridge rectifier behavior, relay switching, 220V/380V input logic and a boosted DC bus around 530-560V.
Input power section
The ZX7-250 power-board explanation describes two bridge rectifiers used functionally as a single bridge arrangement, with one path handling one half-cycle and another path handling the opposite half-cycle. Relay switching changes depending on whether the input is 220V or 380V. In the described platform, the DC bus target is around 530-560V.
Input stage diagram
Diagnostic table
| Check | Expected | Abnormal meaning |
|---|---|---|
| Bridge rectifier paths | no short, correct rectifier behavior | shorted bridge lights lamp limiter or blows fuse |
| Relay action on 220V | two relay action described in notes | wrong state may prevent correct bus |
| Relay action on 380V | one relay action described in notes | wrong state can overvoltage or undervoltage bus |
| DC bus | around 530-560V in this platform | too low means boost/switching/input fault; too high is dangerous |
| Auxiliary supply | feeds control rails after bus/input stage | if missing, control board cannot start |
Safety note
The DC bus is lethal. Do not measure or test the boost section unless you are qualified and using rated probes, isolation and discharge procedures.