Ilpi-354: V.a Schematic Work

Hunting the Ilpi-354 V.a Schematic: A Restoration Detective Story

If you’ve landed here, chances are you’re holding a dusty Ilpi-354 V.a power supply — or at least its carcass. Maybe it’s a linear bench supply from the 1980s, a German-made lab unit, or a module from an old intercom system. One thing is certain: the schematic is nowhere to be found in the usual places.

After two weeks of digging through PDF archives, dead forum links, and German eBay listings, here’s what I’ve learned about tracking down the elusive Ilpi-354 V.a schematic — and how you might resurrect your unit without letting the magic smoke escape. Ilpi-354 V.a Schematic

Step 3: Examine the Gate Drive

Schematic Reference: Section 2 to 3 (Gate resistor) Hunting the Ilpi-354 V

• Disconnect main power. Use a diode mode on your meter across the MOSFET (Drain to Source). If shorted, replace it.
• Check the gate resistor (R_G). On the Ilpi-354 V.a, this is often 15Ω. It burns open when the MOSFET fails.

2. The Starting Circuit (High-Voltage Resistors)

• Schematic Symbolism: R_start (typically two 150k-220k Ω, 2W resistors in series).
• Function: These resistors provide initial base current to one of the switching transistors. Without this, the oscillation cannot begin. Failure here is common: burnt, cracked resistors are a visual clue.

Introduction

The Ilpi-354 V.a (often labeled as ILPI-354 or ИЛПИ-354) is a renowned, rugged switching power supply module originating from Soviet and post-Soviet electronic engineering. Commonly found in industrial controllers, CNC machines, and high-end audio equipment (due to its low-noise characteristics), this unit is prized for its repairability and robust design. Disconnect main power

Understanding its schematic diagram is essential for technicians restoring vintage equipment or hobbyists adapting the unit for modern bench use.