FREQUENCY CHANGER Russian patent published in 2000 - IPC

FIELD: converter engineering; power supplies for heavy-power ozonizers. SUBSTANCE: frequency changer has single-phase bridge rectifier built around diodes 1-4 and single-phase bridge inverter built around transistors 5-8 whose input leads are connected to output ones of rectifier through filter chokes 9, 10 and shorted out by filter capacitor 11; transistors 5-8 are shorted out by capacitors 12-15 and diodes 16-19; it also has series circuits set up of voltage sensor 20 using emitter-group transistor 6, threshold element 21, switching circuit 22, and output stage 23 whose output leads are connected to gate electrodes of transistors 5, 8 connected across diagonally opposite terminals of inverter bridge; series circuit also includes voltage sensor 24 built around second transistor 8 of emitter group, threshold element 25, switching circuit 26, and output stage 27 whose output leads are connected to gate electrodes of transistors 6, 7 across other diagonally opposite terminals of inverter bridge; series circuit also incorporates master oscillator 28 and frequency divider 29 whose first output is connected to second one of switching circuit 22 and second output, to second input of switching circuit 26; input leads of rectifier are connected to those of frequency changer through circuit breaker 30 incorporating independent-release coil 31; rectifier output leads are shorted out by varistor 32; capacitor 11 is shorted out by resistor 33; inverter transistors 5-8 are shorted out by varistors 34-37; inverter output leads are connected to frequency changer ones through series-connected choke 38 and transformer 39 whose secondary winding is connected to ozonizer 40; frequency changer also has series circuit set up of current sensor 41 at rectifier input, filter 42, threshold element 43, flip-flop 44, power circuit 45 for coil 31, sawtooth-voltage generator 46 whose input is connected to output of master oscillator 28, and threshold element 47 whose output is connected to third input of switching circuits 22, 26, voltage sensor 48 connected across diagonally opposite terminals of inverter bridge, filter 49, comparison device 50, feedback signal selecting circuit 51, control circuit 52 whose output is connected to second input of threshold element 47, current sensor 53 placed across diagonally opposite terminals of inverter bridge, filter 54, comparison device 55 whose output is connected to second input of selecting circuit 51, voltage sensor 56 using capacitor 11 whose output is connected to second inputs of threshold elements 21, 25, trigger circuit 57 whose first output is connected to output of threshold element 25 and second one, to second input of flip-flop 44, reference-voltage source 58 whose first output is connected to second input of threshold element 43, second one, to second input of comparison circuit 50, and third output, to second input of comparison circuit 55. EFFECT: enlarged functional capabilities. 1 dwg