Signal 230-25-LPI, 40-150-LPI Signal Transformer

The Signal 230-25-LPI and 40-150-LPI are Bel Fuse LPI-series, low-profile, printed-circuit-board signal transformers designed for compact signal isolation and transfer in control and instrumentation electronics. Each unit is a 6 VA transformer in a slim package, with the 230-25-LPI variant offering a 230 V primary and a center-tapped 230 VCT secondary (two 115 V halves) rated up to 50 mA per half (230 VCT @ 25 mA / 115 V @ 50 mA). The 40-150-LPI variant provides two secondary windings: a 40 V center-tapped winding rated at 150 mA and a separate 20 V winding rated at 300 mA, for a total of about 6 VA. Both models are described as Printed Circuit Mount (PCB) low-profile transformers, suitable for tight-board applications where galvanic isolation and signal conditioning are required. Typical uses include isolating and conditioning signals in compact control, instrumentation, and sensing circuits, where precise secondary voltages and modest current capability support interfacing with logic, relays, or diagnostic circuitry. Selecting the correct model hinges on the needed secondary voltage and current: the 230-25-LPI delivers ±115 V outputs for isolation or drive duties, while the 40-150-LPI supplies a 40 V center-tapped path plus a 20 V output for multi-winding signal conditioning.