Converters and Power Supplies for the Communications, Automotive & Marine Industries



The sensitivities of modern electronic equipment to variable input voltages, susceptibility to EMC interference and in some cases, the need to isolate the supply has made voltage stabilisation an important section of our product range. Start/Stop technology on motor vehicles has added to this problem. The DDi Series offers a wide range of 12V-12V and 24V-24V isolated products that ensure a stable and reliable voltage can be delivered to important equipment, even when the electrical system is under duress, such as during engine cranking. Units are available from 36-240W. The range now also offers 48V-12V units, suitable for the telecoms and forklift truck markets. For 12V-24V converters, see DD Series 'Up' Voltage Converters


There are three products in the 12V-12V isolator range from 36W to 108W and a further four products in the 24V-24V range from 72W to 240W. There are also three 48V-12V products from 36W to 108W. All products use modern switchmode designs and are built using the same concepts and technologies as the successful PowerVerter range, which will of course meet your 24V–12V requirements.


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 onto uneven surfaces. It is easy to fit the clip into awkward places, then simply click the unit into position. The green LED indicates when there is output from the converter. This gives reassurance to the installation engineer and speeds fault finding.


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

DD DC input and output
i Denotes isolated converter
12-12 Nominal 12V input and output
036 36W Capacity Unit

Choose your DD Series Product

Part Number Power Nominal Voltage Dimensions (mm) Weight (g)
DDi12-12 036 36W (3A) Isolated 12Vdc input, 12Vdc output 89 x 87 x 50 290
DDi12-12 072 72W (6A) Isolated 12Vdc input, 12Vdc output 167 x 87 x 50 540
DDi12-12 108 108W (9A) Isolated 12Vdc input, 12Vdc output 217 x 87 x 50 780
DDi24-24 072 72W (3A) Isolated 24Vdc input, 24Vdc output 127 x 87 x 50 440
DDi24-24 108 108W (4.5A) Isolated 24Vdc input, 24Vdc output 167 x 87 x 50 540
DDi24-24 168 168W (7A) Isolated 24Vdc input, 24Vdc output 217 x 87 x 50 780
DDi24-24 240 240W (10A) Isolated 24Vdc input, 24Vdc output 217 x 87 x 62 870
DD48-12 072 72W (6A) Non-Isolated 48Vdc input, 12Vdc output 89 x 87 x50 270
DD48-12 108 108W (9A) Non-Isolated 48Vdc input, 12Vdc output 127 x 87 x 50 370
DD48-12 240 240W (20A) Non-Isolated 48Vdc input, 12Vdc output 217 x 87 x 50 770
DDi48-12 036 36W (3A) Isolated 48Vdc input, 12Vdc output 89 x 87 x 50 290
DDi48-12 072 72W (6A) Isolated  48Vdc input, 12Vdc output 127 x 87 x 50 405
DDi48-12 108 108W (9A) Isolated 48Vdc input, 12Vdc output 167 x 87 x 50 560
 Other input and output voltage configurations are available as special orders, please ask our sales team.


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 of 2 minutes followed by 8 minutes rest.
Transient voltage protection Meets ISO7637-2 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 
Off load current (quiescent current) <15mA
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 to IP20)
Connections Four 6.3mm push-on flat blade connectors
Output indicator Green LED adjacent to output terminals
Mounting method Click ‘n’ fit mounting clip, fitted separately using three hole fixture
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
Approvals 2004/108/EC The general EMC directive
2009/19/EC The automotive directive
93/68/EEC The CE marking directive
Designed to  EN50498, ISO 7637-2
Markings CE and E (e) marked