Tracopower thb 3 series 3w dc dc converters tracopower thb 3 1222 these tracopower thb 3 series dc dc converters have reinforced insulation for operating voltages up to 300v ac and a wide 21 input voltage range input filter according to en 55022 class a tracopower thb 3 1222 3w dc dc converter 9 18v dc in 12v dc 125ma out