0-30V Stabilized Power Supply

[HarryA1]

You need to post the schematic you are working from.

Perhaps start a new thread with a similar title? A fresh start is always a good start 

 

[paul .a larner]

its this schem,except im using a 5.1v zenner for the -v supply not the regulator+ im using the mc34071 opamps.,in supposed cc mode the led lights but i can still increase the voltage and the output waveform is horrid,full of spikes,they increase in amplitude as i rotate the voltage pot cw ie increase the voltage,its fine in cv mode.



also i dont have the opamp etc on the top portion of the schematic

 

[HarryA1]

If the spikes are only there while rotating the potentiometer then it is a bad pot.

If they are there in cc mode always then you can trace them back through the op amps output to inputs until you narrow down the source.

 

[Tobias1]

Hi, I have a problem with output voltage. when it's measured without the load I can only adjust it from 0.7V - 2V. However with 820 ohm load it can only output 0.8V - 1.2V. I can't find any high resistance "roads" (don't know how to call them) on the pcb. Any ideas what can be wrong with it? The schematic is a bit adjusted from: https://www.electronics-lab.com/project/0-30-vdc-stabilized-power-supply-with-current-control-0-002-3-a/.

I attached eagle .brd file and screenshots from the same file. Also I use 100k and 10k pots. to tune and fine tune the voltage and current  (can this be the problem?)

The transistors are 2n3055, two together with 0.1 ohm resistors at each emitter. 

Thank you for any advice. 





View attachment PCB.sch

 

[HarryA1]

The best you can do is to start at the  output transistors and work your way back through the circuit. It is impossible to diagnose homemade circuits at a distance as there are just to many places to go wrong.

For others never build something you can buy cheaper. Get two at 8$ each - one for parts.

https://www.ebay.com/itm/Stabilized-Continuous-Adjustable-DC-Regulated-Power-Supply-Kit-0-30V-2mA-3A-L/353345066780?hash=item524501d71c:g:JjsAAOSw~QteWLkt

 

[Tobias1]

I have already ordered that. I tried it to have some experience but it didn't go as planned :/.
Either way, thank you.

 

[wandows]

Hello everybody! I would like to count on the help of friends!!!

In the offset adjustment, my power supply has the output voltage >= 32.9V, and does not reduce to 30V.

Any tips on what can be done to solve this problem?

 

[gixap92915]

I only have unused 15V-18V-20V-24V-CT 5A transformer, how to get it working with liqubyte's 0-30V-rev-8 schematic?

What parts I have to replace/add?

Also does liqubyte's 0-30V-rev-8 is the last stable revision?

Thanks.

 

[a.devincentiis]

Hi everybody,
I improved by digitizing this circuit and replaced the final stage with that of the equally famous K7200.

You can scale it both in voltage and current by changing a few components because the three opamps are always powered at 27V

Sorry, article is not complete and not yet translated into English

https://www.youtube-nocookie.com/embed/ORBUIbtaIQE?feature=oembed

 

[paul .a larner]

can someone tell me how to connect an external rectifier to this?,i have one like an alluminium block with one corner chamfered representing + out from the bridge,can anyone tell me what points to connect what place on the pcb to,a pic would be best,thanks Paul l.

 

[paul .a larner]

anyone?.

 

[paul .a larner]

seems to be dead here!

 

[user469]

The best you can do is to start at the  output transistors and work your way back through the circuit. It is impossible to diagnose homemade circuits at a distance as there are just to many places to go wrong.

For others never build something you can buy cheaper. Get two at 8$ each - one for parts.

https://www.ebay.com/itm/Stabilized-Continuous-Adjustable-DC-Regulated-Power-Supply-Kit-0-30V-2mA-3A-L/353345066780?hash=item524501d71c:g:JjsAAOSw~QteWLkt

View attachment 44037

Hi am new here, i recently bought the kit, its ok to use schema and part list rev 7 for 3A with two output transistors ?

I plan to use a pair of 2N3055 or there is a better choiche ? Thanks

 

[linkz]

can somebody explain how Audioguru calculated the resistors R13 and R14 for the transistor Q1 on his rev7 schematic?

 

[Delta Prime]

can somebody explain how Audioguru calculated the resistors R13 and R14 for the transistor Q1 on his rev7 schematic?

Yes.
You have to start a new thread and reference this one and also reference the schematic itself. there areeover 2000 responses to this one thread that will probably be closed now locked up.
In the meantime See Here.

 

[davenn]

too many posts that were not related to the OP
People should start their own threads

this ine now closed