Voltcraft sdc voltage switched mode dcdc converter 138v dc out voltcraft 511520 the voltcraft sdc 225 275w switched mode dcdc converter enables operation of 12v dc consumer items such as cold bags refrigerator boxes or cabinets and mobile hifi units from a 24v dc battery supply system the 24v dc supply is converted to 12v dc via a clocked ic controlled circuit this device is characterized by small dimensions and low weight compared with conventional in line voltage transformers the de