hi, i have made a smps , 12V to 40+/- smps switched at 40Khz , its capable of putting around 40 amps . (load testing yet to be done), its remote turn on by enable pin of SG3525 which helps remote on off and voltage regulation by P WM.
Now i have very nice Focal amplifiers and i have increased its bias from 100mA to 400mA , the output device is 2SC5200/4913 complementary pair driven by TIP 102/107 darlington in emitter follower stage through a 2.2 Ohm resistor from TIP102 emitter to 5200 base .
now the amplifier is in class A for (30 volt rail x 0.4A= 12W peak, 6W RMS ) so its 6W dissipation per device, 12W for 1 channel and 48 Watt for 4 channels, the ammeter reads a continuous but stable 6 Amp draw at 14volt on power supply. the amplifer with this state remains quite warm but not too hot even after two hours.
Objective.I want to use each channel out put from each device to drive a class A stage to be fed by 5200 , with 4 devices with 0.5 amp IQ i would dissipate (40 Vx0.5x4 amp= 80W peak, 40W RMS ) per device set, 80W rms on each pull/push per channel;;;;;;;;;;;so i can get around 40W RMS class A,. per channel.
with 4 channels i will be dissipating 320Watts to get around 160 w(theroretical) watts with 2 channels in bridged mode will give me monoblocks of around 80W per channel. SQ is the objective.
Now in order to do it i want the emitters of 5200 cutt off from ground rail and fed via around 8 ohm to groung (to keep the local feed back in output stage and NFB loop intact ) by this way i can divert more current to bias the additional third stage of 4x5200 transistors i want to add.
Any ideas ? (The reason for using Focal amp is the low level signal/drive ciruitary i want to avoid and just enahcne the current gain at the output stage through and additional power supply) i know its a lot of heat for boot but i intend to do it , i may latter reduce the wattage if 80W RMS bridged is too much .
Regards
Now i have very nice Focal amplifiers and i have increased its bias from 100mA to 400mA , the output device is 2SC5200/4913 complementary pair driven by TIP 102/107 darlington in emitter follower stage through a 2.2 Ohm resistor from TIP102 emitter to 5200 base .
now the amplifier is in class A for (30 volt rail x 0.4A= 12W peak, 6W RMS ) so its 6W dissipation per device, 12W for 1 channel and 48 Watt for 4 channels, the ammeter reads a continuous but stable 6 Amp draw at 14volt on power supply. the amplifer with this state remains quite warm but not too hot even after two hours.
Objective.I want to use each channel out put from each device to drive a class A stage to be fed by 5200 , with 4 devices with 0.5 amp IQ i would dissipate (40 Vx0.5x4 amp= 80W peak, 40W RMS ) per device set, 80W rms on each pull/push per channel;;;;;;;;;;;so i can get around 40W RMS class A,. per channel.
with 4 channels i will be dissipating 320Watts to get around 160 w(theroretical) watts with 2 channels in bridged mode will give me monoblocks of around 80W per channel. SQ is the objective.
Now in order to do it i want the emitters of 5200 cutt off from ground rail and fed via around 8 ohm to groung (to keep the local feed back in output stage and NFB loop intact ) by this way i can divert more current to bias the additional third stage of 4x5200 transistors i want to add.
Any ideas ? (The reason for using Focal amp is the low level signal/drive ciruitary i want to avoid and just enahcne the current gain at the output stage through and additional power supply) i know its a lot of heat for boot but i intend to do it , i may latter reduce the wattage if 80W RMS bridged is too much .
Regards
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