If you install LTspice and add my collection of models (there is a link to it on this forum), then I will upload my schema and you will be able to independently explore this project.

I have LT spice installed. But the thing is I only know basics of it.
Please upload your schematic I'll try to do something, whatever at my level is possible. I don't know what calculations are needed. I have learned ac and dc analysis in college but never came to knew where to implement it.

 

I'll do it on Monday.I will demonstrate how the input voltage is filtered, as well as the response to a fast load change.

 

I'll do it on Monday.I will demonstrate how the input voltage is filtered, as well as the response to a fast load change.

Okay Sir!

 

Hi Audioguru,
You gave me schematic of power supply based on TLE2141, but the thing is i can't find that IC anywhere in local electronics market. It is available on AliExpress which costs more than anticipated.
You once told me that schematic based on tl081 has a flaw, that it requires negative voltage to run. Can you please redesign the schematic according to the tl081.

Rahul, you are on the other side of the world where everything is different. The cost of a TLE2141 from AliExpress and shipped to India is cheaper than it should be so they are probably selling cheap Chinese fakes. Go to www.farnell.com and click on the flag of your country. They sell good quality electronic parts at normal prices, a real TLE2141 costs the same as a cup of coffee which costs almost nothing.

Yes, the TL081 does not work if an input is within a few volts from the negative supply so the negative supply must be at least -5.6V. But its total maximum supply is only 36V so the positive supply must be +30V or less and the circuit losses will limit the maximum loaded output of the circuit to only +24V or +25V, not +30V. Bordodynov shows the circuit using TL081 opamps with a low NEGATIVE output voltage.

The circuit I showed uses a negative half-wave rectifier and two series diodes to regulate its output to about -1.3V. Then the output of U3 can go down to -0.7V to feed D9 which reduces the input voltage of U2 low enough to limit the output current.

Bordodynov also shows a circuit using lousy old LM324A opamps in one IC that will probably overheat. The LM324 is noisy, has crossover distortion and is slow. His driver transistor has voltage gain which might cause the circuit to oscillate.

 

Rahul, you are on the other side of the world where everything is different. The cost of a TLE2141 from AliExpress and shipped to India is cheaper than it should be so they are probably selling cheap Chinese fakes. Go to www.farnell.com and click on the flag of your country. They sell good quality electronic parts at normal prices, a real TLE2141 costs the same as a cup of coffee which costs almost nothing.

Yes, the TL081 does not work if an input is within a few volts from the negative supply so the negative supply must be at least -5.6V. But its total maximum supply is only 36V so the positive supply must be +30V or less and the circuit losses will limit the maximum loaded output of the circuit to only +24V or +25V, not +30V. Bordodynov shows the circuit using TL081 opamps with a low NEGATIVE output voltage.

The circuit I showed uses a negative half-wave rectifier and two series diodes to regulate its output to about -1.3V. Then the output of U3 can go down to -0.7V to feed D9 which reduces the input voltage of U2 low enough to limit the output current.

Bordodynov also shows a circuit using lousy old LM324A opamps in one IC that will probably overheat. The LM324 is noisy, has crossover distortion and is slow. His driver transistor has voltage gain which might cause the circuit to oscillate.

Per piece of tle2141 costs more than $2 which is 141INR. On comparison to TL081 which here costs less than 20INR.
That's a huge amount of money.
Isn't there any alternative?

 

Hi rahul411.
You can buy LM324 (inside the quad-amplifier)?If not, there is no point in investigating my scheme.
I can argue Audioguru.Concerning crossover distortions: they are easily greatly reduced by translating this
operational amplifier in the mode of operation of class A (adding only one resistor, and in my scheme this mode).
I made a transistor spice model (LM324_AB), which completely mimics all properties, including crossover distortion.
I have a selection of LTspice schemes in which I do a testing model.
Let's return to our sheep.
The combination of an operational amplifier and a cascade with a common emitter greatly increases the speed.
Yes, there is a stability problem, a more complex correction is required, but what is LTspice for.
In occasion of noise of the amplifier. The source of the reference voltage on the Zener diode makes the main contribution to the noise.

 

Hi rahul411.
You can buy LM324 (inside the quad-amplifier)?If not, there is no point in investigating my scheme.
I can argue Audioguru.Concerning crossover distortions: they are easily greatly reduced by translating this
operational amplifier in the mode of operation of class A (adding only one resistor, and in my scheme this mode).
I made a transistor spice model (LM324_AB), which completely mimics all properties, including crossover distortion.
I have a selection of LTspice schemes in which I do a testing model.
Let's return to our sheep.
The combination of an operational amplifier and a cascade with a common emitter greatly increases the speed.
Yes, there is a stability problem, a more complex correction is required, but what is LTspice for.
In occasion of noise of the amplifier. The source of the reference voltage on the Zener diode makes the main contribution to the noise.

Yes, LM series is available.
Quad amplifier means 14 pin IC with 4 opamp in it just like lm339?

Also another doubt. You said LM324_AB is it mandatory to use that model only or any LM324 will do the job?

 

LM339 is comparator!
Any spice model is suitable for modeling, but my model reflects all the nuances of behavior.I developed it after one person complained of the discrepancy in the results of calculation and real behavior.He used a very large capacity in the load.As a result, in reality, there was generation, but in modeling it was not.My model reproduced reality.Many models of operational amplifiers do not correctly model the output impedance.
AB is my initials (Alexander Bordodynov). In my collection there are several models of LM324. From many companies. This operational amplifier is even done in Belarus.

 

Since you've already built the circuit, why not use normal techniques to troubleshoot?

Is this a circuit that you designed? Or is it something someone else designed and you don't know how, or if, it works?

Using a simulator for a power supply circuit seems like overkill.

A right reading for people like me who don't like reading rotated schematics:
View attachment 151305

I also do not like reading circuits from up to down or right to left.

A possibility of simulators is : OrCad, not Proteus, Protel or Althium designer.

However here the circuit will most likely work on the simulator, but not on the board.

Possible reasons for that are: on the simulator you will make the circuit properly, there is a bad connection on the board and you should check with an oscilloscope or voltmeter, the use of capacitors and resistors can lead to a change in their value because of the temperature of the environment and different batch from the shop, that's why for power supply control they are not recommended.

 

hi ATD'
I would disagree with your comments regarding using LTSpice simulations to check out the design of a power supply.
It is important to point out that LTSpice will not do the design for you, thats your job, but it will highlight any shortcomings in the design.

It is possible using LTS to check the performance of the circuit over a range of operating temperatures.

Where is it stated that LTS is not recommended for testing out a power supply design.?

Eric

 

hi ATD'
I would disagree with your comments regarding using LTSpice simulations to check out the design of a power supply.
It is important to point out that LTSpice will not do the design for you, thats your job, but it will highlight any shortcomings in the design.

It is possible using LTS to check the performance of the circuit over a range of operating temperatures.

Where is it stated that LTS is not recommended for testing out a power supply design.?

Eric

I never said that! What I said is that if there is a bad connection soldered on the board, no matter which simulator he uses, he will not reproduce the mistake on the simulator and simulating the circuit is pointless, except for the temperature check. Its better to use an oscilloscope or voltmeter.

 

that's why for power supply control they are not recommended.

hi,
I guess we are still just on Topic regarding simulators for testing.
So I and others do not misunderstand, what are you saying 'is not recommended', the way your post reads is a little ambiguous.

Why is simulating a power supply design pointless.?

I would agree a bad project build will cause problems,
E

 

hi,
I guess we are still just on Topic regarding simulators for testing.
So I and others do not misunderstand, what are you saying 'is not recommended', the way your post reads is a little ambiguous.

Why is simulating a power supply design pointless.?

I would agree a bad project build will cause problems,
E

What I meant by that is that the values of the capacitors and resistor can move, especially if they are 5-20% components and with the temperature the difference increases. That can cause a circuit not to work, I have seen this problem before.

For simulating, whatever wrong soldering you have on the board will be impossible to reproduce on the simulator.

 

For simulating, whatever wrong soldering you have on the board will be impossible to reproduce on the simulator.

But surely that statement will apply to any circuit, the builder has used as a source diagram, not just a simulator.??
You are confused over the purpose of using a simulator to check out a design, its used to check the operation of the circuit prior to building it.

A simulator is not designed to correct for bad circuit build/construction.

 

But surely that statement will apply to any circuit, the builder has used as a source diagram, not just a simulator.??
You are confused over the purpose of using a simulator to check out a design, its used to check the operation of the circuit prior to building it.

A simulator is not designed to correct for bad circuit build/construction.

In this case we have a built circuit, that was working the first time it was built and not working the second time. The simulating was needed before the circuit was built, now that we know it works for certain, there is no need to simulate it anymore. And whatever problem there is, comes from the soldering or something else then the design.

Edit: except for the temperature check, that can be tested with a simulator.

Everything else will require an oscilloscope or voltmeter to see where the error is.

 

That was my point in the first post.

 

Don't think I am a sheep and you can give out tour hatred towards me, because of the other thread!

 

The point which you are missing is the TS Topic, he wanted confirmation in checking out a circuit he had found on the web, before building.
It was a wise move on his part, as the original design had a number of design flaws, which a simulation highlighted.

Fellow members have corrected the design flaws and demonstrated using simulations that the design is now OK to build.

Would you just go ahead and build an unproven circuit.????

 

Don't think I am a sheep and you can give out tour hatred towards me, because of the other thread!

hi ATD,
You are seriously misunderstanding me, I have no dislike for you at all.
I thought we were having an interesting discussion regarding the benefits of simulators, that would prove useful to other readers, nothing more.
Eric

 

Whether LTspice can be used to test the voltage regulator circuit depends on the skills and knowledge of the basics of circuit technology.
For example, the frequency response can be considered using the Monte Carlo method (LTspice allows you to do this).In this case, you specify the values of resistors and capacitors, which will change randomly.When I design an analog circuit, I "move" the values of the elements.But I consider the main knowledge of how your circuit works.
As I said before: my scheme is a zero option. I have not yet done a thorough testing and optimization. By this I mean checking for resistance to changes in the values of the circuit elements and the load (current and capacitance) at different output voltages. Also I check the work with the impulse load.