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This is somehow close to my project so I want to ask what transistors were those 3 and how will this be connected to the circuit? I don't have the knowledge of what you meant where the negative feedback from output is and which are the output transistors. Is the 4.7k pot the one you are referring as the pot from the zener diode?Your new circuit will not work because the added transistor turns off when the output voltage is less than about 27.5V. Also the voltage-setting pot turns down the amount of negative feedback when its voltage is turned down.
I made an extremely simple opamp with 3 of the transistors of an LM358 opamp. It has a non-inverting input for your adjustable reference voltage (a pot from the 27V zener diode) and it has an inverting input for negative feedback from the output. Its inputs should work all the way down to ground.
Can you calculate its resistor values?
i'm quite confuse to the 2 BC547B since the circuit shows an PNP transistor but BC547B is an NPN transistor.Maybe you have not learned enough about basic electronics to understand this very simple circuit.
The BC547B transistor that you used in your schematic is fine for all the low current transistors in my new circuit.
Negative feedback from the output causes the error amplifier to correct any difference between the reference voltage from the voltage-setting pot and the output voltage.
The output transistors are the three transistors in your circuit.
whose circuit? ladyphoebe15's circuit or audioguru's circuit?Check your circuit again (transistor types).
And the circuit needs some more components and more 2N3055s to cope with 3 Amps,but I guess you'll come to that eventually.
i'm quite confuse to the 2 BC547B since the circuit shows an PNP transistor but BC547B is an NPN transistor.
I wanted young lady Phoebe to notice my errors on purpose. If the output is shorted then I hope she is not burned by the very high temperature of the 2N3055.Check your circuit again (transistor types).
And the circuit needs some more components and more 2N3055s to cope with 3 Amps.
Can the 2 PNP transistors be any PNP transistors? Is changing the 2N3055 to another transistors or adding a heatsink solve the problem for being burned?I wanted young lady Phoebe to notice my errors on purpose. If the output is shorted then I hope she is not burned by the very high temperature of the 2N3055.
BC557B or 2N3906 PNP transistors have a low range of hFE and should be used for the input transistors.Can the 2 PNP transistors be any PNP transistors? Is changing the 2N3055 to another transistors or adding a heatsink solve the problem for being burned?
what does it looks like in a circuit?The aluminum heatsink must be enormous with many fins and a high speed fan must be used.
Two 2N3055 transistors with series emitter resistors should be used to share the heat on a pretty big heatsink.
How do you calculate the values for the resistors?Your new circuit will not work because the added transistor turns off when the output voltage is less than about 27.5V. Also the voltage-setting pot turns down the amount of negative feedback when its voltage is turned down.
I made an extremely simple opamp with 3 of the transistors of an LM358 opamp. It has a non-inverting input for your adjustable reference voltage (a pot from the 27V zener diode) and it has an inverting input for negative feedback from the output. Its inputs should work all the way down to ground.
Can you calculate its resistor values?
is that classified as a discrete components?Hi,
Does it have to be a linear regulator or can it be a switcher? Higher current and voltage works out better with a switcher in many cases.
is that classified as a discrete components?
How do you calculate the values for the resistors?
I would begin with R4. You want its value to be low enough so that it turns on the output transistors well but does not overheat Q3. The datasheet shows that it is very hot at 625mW so let us select 180mW.I've configured my circuits using the op amp negative feedback of audioguru. I have simulated with Proteus and I assigned the two resistors value about the PNP transistor =1.2k while the one below=820. Not sure of how to know what values of resistors is really needed.