Engineering Sales PC 75 battery charger/power supply Repair Service

The Todd Engineering Sales PC‑75 is a 75 A industrial battery charger/power supply designed for automotive and heavy‑equipment applications, typically delivering 12 VDC or 24 VDC output with built‑in protection circuits.

Common failure points in units of this class include: degraded input capacitors or rectifier diodes causing ripple; overheating of the transformer windings leading to insulation breakdown; failure of the internal MOSFETs or switching ICs due to overcurrent/voltage spikes; and loss of output regulation from a faulty voltage reference or feedback network. The charger may also exhibit intermittent operation if the input power supply is unstable or if the battery load exceeds its rated capacity.

First‑check diagnostics: verify that the unit receives correct mains voltage (or DC input) with an oscilloscope to check for spikes; measure the output voltage and current capability under a known load, noting any droop or oscillation; visually inspect the PCB for burnt components, cracked solder joints, or swollen electrolytics. If available, review the serial‑port or diagnostic LED status for error codes that indicate overtemperature, short‑circuit, or undervoltage conditions.