LM317T Voltage Regulator with Pass Transistor

First test of the amp with the two channels. there are : - this is a AB class push pull with EL34 - i used a shcmitt phase inverter, but between +300V and -150V (not +300 and GND), to get maximum linearity and drive the EL34 correctly. Just before the phase inverter are two OPA OP amp to get some gain ! (at these place there is no reason for me to put a tube, OPA amp are really quiet) - there is one fully insulated digital bus for all board to communicate with each other (pic microcontroller). they can synchronize and the startup is done correctly (heating and then high voltage). Also if something gets wrong, automatic shutdown (polarization failure for instance) - 2 boards for the high voltage +400V (notice the so small capacitor of 200uF, and only 100mV ripple at 40W output). made with IGBT of 1200V to be sure there is no breakdown, and feedback to lower the noise. - one board for +12.6V DC heater for the two phase shifter tubes. - one board for low power +300V and -140V (for the phase shifter) - the EL-34 tubes are with a foot resistor of 1 ohms each, and a card ( AL_POL_01) measures the voltage across the 1 ohm resistor to determine the current and adjust the polarization voltage. - two board for automatic bias tuning ( AL_POL_01): each measures the current on two tubes and tune the bias voltage with DAC to get 30mA on each tube. - one central board allways powered, controls the static relay for the high voltage and the other boards supplies. - one big toroidal ...



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