Product Description:

The PST610-EW belongs to the PST Thyristor Power Units series manufactured by Bosch Rexroth Indramat. This power unit is built for medium-frequency welding and induction systems that need stable current modulation rather than simple on-off contactor control. It converts the transformer’s primary power into a regulated secondary current and acts as the interface that lets a PLC vary heat output in real time inside automated production cells.

The internal silicon pair uses a 2-phase thyristor topology, so each half cycle can be phase-angle controlled independently for fine resolution. Under continuous duty, it delivers up to 130 Arms; when the duty cycle is limited to 20%, the same bridge can pulse as high as 300 A to support short welding bursts. The matched transformer is rated at 95 kVA, which provides enough volt-ampere capacity to keep the firing angle in its linear operating range. An enclosure rating of IP20 provides finger-safe protection for cabinet mounting. Water flows through an integrated heat sink to remove junction losses, and a metal-oxide varistor stack provides overvoltage suppression. Additional hardware includes a 2.2 kΩ discharge resistor for field collapse, a 0.5 VA I/O field power budget, and a 0.1 A auxiliary output for low-power indicators.

Control signals arrive on galvanically isolated terminals that accept 24 VDC logic, with the card drawing up to 4 A from that rail during gating events. The interface supports 16 opto-coupled discrete inputs for command patterns and 12 transistorized outputs for process feedback, and each input loads the source by only 3 mA. A dedicated 1 A solenoid channel drives pneumatic valves, while water cooling helps limit thermal drift during repeated operation. MOV clamps, the low input burden, and the discharge resistor help remove stored energy quickly when the PLC issues a stop command.