• DD12-24-072
  • DD12-24-168
  • DD48-12-072
  • DD48-12-108
  • DDi12-12-036
  • DDi12-12-072
  • DDi24-24-072
  • DDi24-24-108
  • DDi24-24-168
  • DDi24-24-240





  • DC Train Applications
  • Power Boat Navigation
  • Snowplough
  • Police Motorcycle
  • Petrol Tank Converters
  • Airport Tow Communications

DD and DDi Series Voltage Converters

If you need to fit 24V equipment onto a 12V vehicle, then an up converter from the DD Series offers a fast and easy way to configure your system. Or, if you need to stabilise your voltage or isolate your supply, then the DDi Series of 12V-12V and 24V-24V Isolators will suffice. There are also 48V-12V units available for telecoms and forklift truck applications.

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

For a Wide Range of Applications

These 12V units are ideal for small vehicle applications such as cars, minibuses, small marine craft, caravans and motorhomes and a variety of industrial uses.

12V-12V and 24V-24V units provide a stable output voltage as well as providing galvanic isolation for a variety of application.

A Wide Product Range

There are three 12V-24V products in the range running at currents from 3A (DD 12-24 072) to 10A (DD 12-24 240), while there are 5 more products from 3A – 10A in the 12V-12V and 24V-24V isolator range. All products use modern switchmode designs and are built using the same manufacturing concepts and technologies as the successful PowerVerter range which will of course meet your 24V-12V requirements.

Fast Installation

All the units consume an off load current of less than 15mA, which is probably less than the self discharge current of the vehicle’s battery. All the products fit onto a ‘Click ‘n’ fit’ mounting clip which is fixed in three points allowing it to be mounted on uneven surfaces. It is easy to fit the clip into awkward places, then simply click the unit into position. A red LED indicates when there is output from the converter. This gives reassurance to the installation engineer and speeds fault finding.

The 12V-24V converters have been used for a variety of applications including bus ticketing systems on mini buses and for 24V bow thrusters on leisure craft.

The product code is developed as follows taking the DDi 12-12 036 as an example:


DC input and output


Denotes isolated converter


Nominal 12V input and output


36W Capacity Unit

Choose your DD Series Product

Part Number Power Nominal Voltage Dimensions Weight
DDi 12-12 036 36W (3A) Isolated 12Vdc input, 12Vdc output 89 x 87 x 50mm 290g
DDi 12-12 072 72W (6A) Isolated 12Vdc input, 12Vdc output 167 x 87 x 50mm 540g
DDi 24-24 072 72W (3A) Isolated 24Vdc input, 24Vdc output 127 x 87 x 50mm 440g
DDi 24-24 108 108W (4.5A) Isolated 24Vdc input, 24Vdc output 167 x 87 x 50mm 540g
DDi 24-24 168 168W (7A) Isolated 24Vdc input, 24Vdc output 217 x 87 x 50mm 780g
DDi 24-24 240 240W (10A) Isolated 24Vdc input, 24Vdc output 217 x 87 x 62mm 880g
DD 12-24 072 72W (3A) Non-Isolated 12Vdc input, 24Vdc output 89 x 87 x 50mm 300g
DD 12-24 168 168W (7A) Non-Isolated 12Vdc input, 24Vdc output 167 x 87 x 50mm 640g
DD 12-24 240 240W (10A) Non-Isolated 12Vdc input, 24Vdc output 217 x 87 x 50mm 820g
DD 48-12 072 72W (6A) Non-Isolated 48Vdc input, 12Vdc output 89 x 87 x 50 mm 260g
DD 48-12 108 108W (9A) Non-Isolated 48Vdc input, 12Vdc output 127 x 87 x 50 mm 360g
DD 48-12 240 240W (20A) Non-Isolated 48Vdc input, 12Vdc output 217 x 87 x 50 mm 780g
Other input and output voltage configurations are available as special orders, please ask our sales team


Technical Data

Input voltage range 12Vdc, 24Vdc and 48Vdc +/- 30%
Output voltage 13.6Vdc or 27.2Vdc +15% -20% at extremes of temperature, load, input tolerance, etc.
Intermittent output power Continuous rating +25%, taken for a maximum f 2 minutes followed by 8 minutes rest.
Transient voltage protection Meets !SO7637-2 International standard for 24Vdc commercial vehicles
Electrostatic voltage protection Meets ISO10605, ISO14892, >8kV contact, 15kV discharge
Output noise <50mV pk-pk (100mV on 24V units) at continuous load. Meets CISPR25 and VDE0879-3
Off load current (quiescent current) <100mA
Power conversion efficiency Typically: 90% for non-isolated units, 85% for isolated units
Isolation >400Vrms between input, output and case, on isolated products only
Operating temperature -25ºC to +30ºC to meet this specification table -30ºC to +80ºC de rate linearly to 0A
Storage temperature -25 ºC to +100ºC
Operating humidity 95% max., non-condensing
Casework Anodised aluminium, glass filled polycarbonate, dust water and impact resistance to IP533 (excludes DDi 24-24 240 which is ventilated and fitted with a cooling fan)
Connections Four 6.3mm push-on flat blade connectors
Output indicator Red LED adjacent to output terminals
Mounting method ‘ Click ‘n’ fit mounting clip, fitted separately using three hole fixing
Safe area protection: Over current Limited by current sensing circuit
Over heat Limited by temperature sensing circuit
Transients Protected by filters and rugged component selection
Catastrophic failure Protected by internal input and output fuses

2004/108/EC The general EMC directive

2006/96/EC The automotive directive

93/68/EEC The CE marking directive

Markings CE and e marked

Alfatronix (Ireland)


Phone: +353 (0)404 62399

C26 Wicklow Enterprise Centre
The Murrough
Wicklow Town
Co. Wicklow