0-30V Stabilized Power Supply

[Rocker1234]

I want to insert fine tuning for voltage.
Can I do that
plz suggest me

[audioguru]

I think a large knob should be used for adjusting the voltage so you can see where it is and adjust it fine or coarse.

If you add a fine adjustment pot in series with the coarse adjusting pot then one pot will frequently be at its end.

[denci]

So i have build the power supply and i replaced sense resitor to 0.27E and i used three paralleled 2n3055 transistor with 0.33E emitor resistor.
I was thinking about max. current, how can i test this most easily??
Other component are unchanged against VER2 of circuit and REV3 of component!

[audioguru]

So i have build the power supply and i replaced sense resitor to 0.27E and i used three paralleled 2n3055 transistor with 0.33E emitor resistor.
I was thinking about max. current, how can i test this most easily??
Other component are unchanged against VER2 of circuit and REV3 of component!

You made the 5A version of the latest circuit. The transformer must be 28V at least 200VA and the heatsink for the output transistors must be huge and maybe have a cooling fan.

Most ordinary inexpensive multi-meters can accurately measure the load current.

[denci]

I think a large knob should be used for adjusting the voltage so you can see where it is and adjust it fine or coarse.

If you add a fine adjustment pot in series with the coarse adjusting pot then one pot will frequently be at its end.

So i must insert 1k pot in series with existing trim pot and adjustale pin combine together??

[denci]

I have onother question, i don't know exactly where is the negative power supply in the schematic of stabilized power supply?
Therefore which connection in circuit should i use to negative set voltage (oV to -30V)?

[audioguru]

So i must insert 1k pot in series with existing trim pot and adjustale pin combine together??

No.
The trimpot is adjusted only one time for calibration. Adjust the trimpot for an output of exactly 30.0V with the coarse and fine pots set to maximum.
The 1k fine pot is connected in series with the coarse 10k voltage setting pot P1.

[denci]

yes, that is what i meaned, but how to connect the adjustable pin of fine pot, together with adjustable pin of 10k pot??

[red baron]

Hi guys
I have trawled through the 123 pages about this project on the first listed subject, and then the 96 pages in this listed project, and I note some confusion and some frustration, so I have spent time trying to filter out a solution for the newcomers to get started and to have success - it's a great project.

Attached is the latest and most commonly used schematic and parts list from Audioguru (a real master!), but it is left up to the enthusiast to design a printed circuit board, and many of us do not have this desire or these skills.

Also attached is the circuit diagram and parts list from Picmaster (the circuits are the same but the part numbering is different!), which also includes a successful printed circuit board design for the 3A or 5A version.

Since I wanted the easy and quickest way forward I made the pcb using the 'laser print and Mommy's iron' method, and then I created a comparison list of how to progress from the Audioguru version to the Picmaster pcb.

I hope that this is helpful to anyone just starting.

[denci]

I have onother question, i don't know exactly where is the negative power supply in the schematic of stabilized power supply?
Therefore which connection in circuit should i use to negative set voltage (oV to -30V)?

Can anyone help me about this??

[audioguru]

I have onother question, i don't know exactly where is the negative power supply in the schematic of stabilized power supply?
Therefore which connection in circuit should i use to negative set voltage (oV to -30V)?

Some of the circuit uses a -1.3V negative supply. It is made from a few parts.

The entire circuit can have an output of 0V to -30V if you connect its + and - outputs in reverse so that the +30V output is used as ground and the 0V output is used as 0V to -30V.

Many people have built two of this project so that the first one has a 0V to +30V output and the second one has a 0V to -30V output. Each project must have its own power transformer.

[vendaf]

Can i replace MC34071 to AD711??? or TLE2141 to AD829???,, cause electronic stores here don't have those components.

[audioguru]

Can i replace MC34071 to AD711??? or TLE2141 to AD829???,, cause electronic stores here don't have those components.

I selected MC34071 or TLE2141 opamps because their inputs work at their negative supply voltage (0V here) and their outputs go down close to their negative supply voltage, and they are available almost everywhere.

The first opamp you guessed about will not work.
I didn't bother looking at the second opamp you guessed about.

[ajax007]

hi every one. i create the original version and work fine
but i have 2.5A at 30v when turn voltage volume under
7v current get to 1,5 A and overload protection
do not work
 please help me
 excuse me for poor english