JB Series Single-Phase Thyristor Regulators

The JB series small and lightweight thyristor regulators for single-phase loads are characterized with high panel installation density.
6-models from 10A rated current to 100A rated current are available.
Two control systems, a phase-angle firing system and a zero-cross firing system, are built.


  • Compact and standalone, mounting space-saving, easy wiring
  • Phase-angle firing/zero-cross firing can be selected according to applications, power source environment, etc.
  • Soft-start, soft-up/down and soft-start at power failure recovery for precise control
  • Automatic frequency judgment function, ramp setting function and low limit setting function are built-in.


Models Rated current
JB-2020 20A
JB-2030 30A
JB-2040 40A
JB-2050 50A
JB-2075 75A
JB-2100 100A


Phase Single-phase
Rated current 20, 30, 40, 50, 75, 100A (to be specified)
Rated voltage 100 to 120VAC, 200 to 240VAC (selectable by terminals)
Rated frequency 50/60Hz (automatic change)
Input signal 4 to 20mADC, 1 to 5VDC or ON-OFF contact signal (selectable by terminals)
Input resistance 100 Ω (4 to 20mADC), 25 Ω (1 to 5VDC)
Output range 0 to 98% of rated voltage
Minimum load current 0.5A (at 98% output)
Applicable load Resistive load, inductive load (primary side control of transformer, flux density 1.2T or lower, phase-angle firing system only)
Control system Phase-angle firing/zero-cross firing (selectable by internal dip switches)
Output setting range Ramp setting (0 to 100%)
Low limit setting (0 to 100%)
Over-current protection Thyristor gate-off (120% or more of rated current, on built-in or external CT)
Other functions Soft-start, soft-up/down (1 to 20 seconds), soft-start at power failure recovery
Dimension H172 x W48 x D143mm (for 20A, 30A)
H188 x W68 x D148mm (for 40A, 50A)
H200 x W116 x D157mm (for 75A, 100A)
Weight About 1.0kg for 20A and 30A, about 1.3kg for 40A and 50A, about 1.9kg for 75A and 100A

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