DC-DC Converters – 12 V, 24 V and 48 V

What does a DC-DC converter do?

A DC-DC converter changes one DC voltage into another: stepping the 24 V of a truck or boat down to 12 V, stepping 12 V up to 24 V, or electrically isolating two circuits. There is no such thing as a “DC transformer”: a transformer only works on alternating current, so DC needs an electronic converter.

Our range has three families:

• 24 V to 12 V DC-DC converter (SDC): a compact, non-isolated step-down unit rated 12/18, 20/26, 30/38, 40 or 60 A. According to the data sheet, the SDC20, SDC30 and SDC60 can also be used as DC battery chargers.
• IP68 waterproof step-down converter: 18 to 36 V input, 12 V output, rated 20, 40 or 100 A, protected against overload, short circuit and overheating. For locations exposed to water and shocks.
• IDC isolated converter: 12, 24 or 48 V input, 12 or 24 V output, 100, 200 or 360 W. It can therefore also step 12 V up to 24 V.

Isolated or non-isolated?

In a non-isolated converter, input and output remain electrically connected: it is the simplest and most affordable way to run 12 V equipment from a 24 V system. In an isolated converter such as the IDC, input, output and housing are separated (isolation voltage above 400 V): this avoids ground loops and protects sensitive electronics, PLCs and radio equipment. The IDC delivers an accurate voltage (±2%) with residual ripple below 50 mV and 85% efficiency.

Choosing the current or power rating

Add up the currents of the 12 V equipment (or divide its total power by 12), then keep some headroom. SDC step-down units are chosen by output current, IDC converters by power: 360 W means 30 A at 12 V or 15 A at 24 V. Mind the temperature: the IDC runs at full load from −20 to +30 °C, then its maximum output current derates linearly to 0 A at 70 °C.

Installation

Fit the converter close to the equipment it supplies, using cables sized for the current; at 12 V and 24 V, currents are high and too small a cross-section causes voltage drop. IDC converters connect with 6.35 mm Faston terminals and are protected against overheating, reverse polarity and overvoltage. For damp or exposed locations, choose the IP68 unit.

Batteries and inverters: the complete system

A DC-DC converter is often paired with our 12 V batteries and, to get 230 V, with a pure sine wave inverter. For a specific need, ask for a quote and we will reply within 48 hours. Business customers get 5% off the whole site with a pro account.