Vermes
Advanced Member level 4
The power amplifier in this design was based on skytec 240 pro housing with pulse power supply of constant power of 750W. The pulse power supply uses driver SG3252, power transistors are IRFP460. The power supply is made in half-bridge technology, stabilized. Capacitors on the mains side are of capacitance of 1500uF/400V (switched by softstart), on the secondary side there are 4 diodes MUR1560 and 10 capacitors 470uF/100V each. Main and control transformer and the choke were made to order. The stabilization now is set to 2x67V DC, under the load the voltage is about +/-3-4V.
While running, you should use an oscilloscope to quickly detect and fix possible problems.
After tests with three halogens 300W/120V each, after 5 minutes of load the heat sink, choke, transformer and rectifier bridge were very warm, the rest of components of the converter was significantly warm.
The converter has declared continuous DC power of 750W/2x75V. The power amplifier is based on 3 pairs of 2sc5200/2sa1943. Both power amplifiers are cooled by tunnel heat sinks with a ventilator. Overload, short circuit and thermal (90 degrees Celsius) protections and softstart operate with the pulse power supply. Protections are for the pulse power supply, pwoer amplifier (against DC at the output). There is also quick disconnection and delayed switching the speakers. Bipolar 2x300W power amplifier was equipped with an optical limiter and subsonic filter (40Hz/36dB/octave and low-pass filter <<16kHz/12dB).
Colors of the connectors:
- red is +
- blue is -
- black is GND
- yellow is speakers
- green is AC 230V
Declared power of the converter is about 750W of constant power, output power of the amplifier is 2x300W RMS/4R and 2x200W/8R.
Pictures:
Link to original thread - Bipolar 2x300W z zasilaczem impulsowym 750W i zabezpieczenia
