Linear Mode Low Power High Voltage DC-DC Converter L. Dimitrov, B. Kunov, I. Vankov INRNE, BAS, Sofia A low power high voltage DC-DC converter, operating at linear mode is described. A linear mode is chosen in order to minimize the noise at the output. Due to the low power an asymmetric generator is used. A device of this type is designed and investigated experimentally. It is intended for supplying the photodetectors in the hadronic calorimeter (HCAL) of the CMS detector in CERN-Geneva. Its basic parameters are: input voltage – 48 V; output voltage – 0-14 kV; maximal output current – 40 uA. The experimental results show, that due to the power losses in the high voltage transformer, best efficiency could be obtained at sinusoidal form of the a.c. voltage. Also the total efficiency of the converter at nominal rate strongly depends on the voltage drop at the regulating transistor. |