The article reveals the hybrid circuitry tube output stages .
1 shows a powerful hybrid single-ended output stage with a balanced input on the lamp GM70 . It is well known that the buildup lamp GM70 is a very difficult task . Meanwhile, simultaneously applying buildup on the grid and cathode circuit , this problem is simplified greatly . Namely, when a buildup is required in two of minimal stress, the Miller effect is eliminated while at the output stage increases its linearity. To debug mode was assembled on a breadboard circuit consisting of two powerful Driver hybrid cascade cascades and the lamp GM70 and FET . The principle of operation of the circuit . Balanced input signal , getting on the net and the gate of FET is summed up in the space charge between grid and cathode lamp 6N6P . Plate load Lamp Driver stage 6N6P power generators are on the field and bipolar transistors . The resistance R22 and R27 in the gate circuit , and the capacitor C14 and C15 are noise suppression for the zener diode D6 and D9. Given that the collector current generator circuit is not connected to the load and to the high voltage power supply line , respectively, such that the generator current is absent and the Miller effect is therefore increased frequency response of the hybrid driver . In addition, the series connection of the two transistors in the generator current increases its input dynamic resistance . However, at the junction of the source and emitter of the transistor KT973 , with a gain of about 1000 , a low output impedance , (Ri lamp decreases at 1000) that allows for high frequencies effectively manage the grid capacitance GM lamp 70 and the gate capacitance of the FET included in the cathode lamp circuit GM70 . To stabilize the operating mode ( lamp current ) GM70 , applied circuit consisting of an operational amplifier and the control transistor OR07 S4793 . Current stabilization occurs as follows. Suppose that at a given time the lamp current GM70 began to increase . Simultaneously with this increase will occur and the current measuring resistor R10, therefore , increase the voltage across this resistor . This measured voltage is applied to the inverting input of the operational amplifier . And the output voltage of the operational amplifier decreases , and decreases the voltage at the emitter of transistor T2 is consequently reduced as the collector current of the transistor , and the voltage at the collector of T2 to increase. This voltage across the resistor R5 and R3 will be applied to the gate of the FET IRF9240. Correspondingly increase the voltage at the source and at the cathode lamp GM70 . Given that the grid of the tube GM70 has zero potential, increasing the voltage at the cathode is equivalent to a decrease in the grid voltage . Thus, the circuit returns to the equilibrium state stabilization quiescent current . Given that there is a device in the amplifier current regulation , when you change the output tubes , at long term work , as well as changing the lamp voltage anode GM70 scheme automatically will set the trimmer R1 operating current (quiescent) output tube . To combat the background used in the output stage of the two half-period rectifier with midpoint . For soft-start glow GM70 the midpoint included resistance R30, which is one minute closed control relay contacts . In this case , the inrush current in the heater circuit does not exceed 3.5 Amps. All modes are indicated in the diagram.
1 shows a powerful hybrid single-ended output stage with a balanced input on the lamp GM70 . It is well known that the buildup lamp GM70 is a very difficult task . Meanwhile, simultaneously applying buildup on the grid and cathode circuit , this problem is simplified greatly . Namely, when a buildup is required in two of minimal stress, the Miller effect is eliminated while at the output stage increases its linearity. To debug mode was assembled on a breadboard circuit consisting of two powerful Driver hybrid cascade cascades and the lamp GM70 and FET . The principle of operation of the circuit . Balanced input signal , getting on the net and the gate of FET is summed up in the space charge between grid and cathode lamp 6N6P . Plate load Lamp Driver stage 6N6P power generators are on the field and bipolar transistors . The resistance R22 and R27 in the gate circuit , and the capacitor C14 and C15 are noise suppression for the zener diode D6 and D9. Given that the collector current generator circuit is not connected to the load and to the high voltage power supply line , respectively, such that the generator current is absent and the Miller effect is therefore increased frequency response of the hybrid driver . In addition, the series connection of the two transistors in the generator current increases its input dynamic resistance . However, at the junction of the source and emitter of the transistor KT973 , with a gain of about 1000 , a low output impedance , (Ri lamp decreases at 1000) that allows for high frequencies effectively manage the grid capacitance GM lamp 70 and the gate capacitance of the FET included in the cathode lamp circuit GM70 . To stabilize the operating mode ( lamp current ) GM70 , applied circuit consisting of an operational amplifier and the control transistor OR07 S4793 . Current stabilization occurs as follows. Suppose that at a given time the lamp current GM70 began to increase . Simultaneously with this increase will occur and the current measuring resistor R10, therefore , increase the voltage across this resistor . This measured voltage is applied to the inverting input of the operational amplifier . And the output voltage of the operational amplifier decreases , and decreases the voltage at the emitter of transistor T2 is consequently reduced as the collector current of the transistor , and the voltage at the collector of T2 to increase. This voltage across the resistor R5 and R3 will be applied to the gate of the FET IRF9240. Correspondingly increase the voltage at the source and at the cathode lamp GM70 . Given that the grid of the tube GM70 has zero potential, increasing the voltage at the cathode is equivalent to a decrease in the grid voltage . Thus, the circuit returns to the equilibrium state stabilization quiescent current . Given that there is a device in the amplifier current regulation , when you change the output tubes , at long term work , as well as changing the lamp voltage anode GM70 scheme automatically will set the trimmer R1 operating current (quiescent) output tube . To combat the background used in the output stage of the two half-period rectifier with midpoint . For soft-start glow GM70 the midpoint included resistance R30, which is one minute closed control relay contacts . In this case , the inrush current in the heater circuit does not exceed 3.5 Amps. All modes are indicated in the diagram.
