cheap DC power supply that an do +/-5v

[prune]

Hi there,

I searched (probably badly) but can't find the info i'm looking for...

I'm looking for a cheap DC power supply that can do +/- 5v (or other voltages) for playing with op-amps and other stuffs like that.
Back in school (in the 80s), we used to have dual output DC power supply that we were bridging and using the middle connector as our "gnd" (0v).

What about now ?
I'm seeing a lot of Chinese made DC power supply like 30v 10A, for 75$ (in Canada) https://www.amazon.ca/gp/product/B07GCKHKC6/ref=ox_sc_act_title_3 or dual output for 300$  https://www.amazon.ca/gp/product/B09YS47GYF/ref=ox_sc_act_title_4... but can I bridge 2 small or the 2 outputs from the bigger one to get symetric voltage ?

Any other recommendation if not ?
I'm a hobbyist so I don't want to break the bank for it... and I think it does not have to be super quality/low noise either for what I want to "play with".

Thanks !

[myf]

Hello,

Maybe you can  use two ruideng dps-3005 with TWO laptop power supply unit. Series connection of these power supplies is possible, but they must not be connected in parallel.
Diodes in series on both outputs prevent current from flowing “the wrong way” through the DC/DC converter.
The circuit can also be protected by an inverting diode on both power supply poles. The aim is to prevent the generator receiving current in the wrong direction, as this destroys these poorly protected power supplies.
A dual power supply is not necessary with all op-amps. Some circuits and assemblies don't need a midpoint, or the midpoint can be obtained as the midpoint between two resistors in series (connected to (+) and (-)).

F. with the DeepL.com free version help ! 

[prune]

thanks for the reply !

I just saw a video on youtube, using a siglent dual power supply, and having the middle point set on the ground... so:

channel 1: + will be your main positive
channel 1: - linked to ground
channel 2: + plugged to the ground
channel 2: - is the main negative
ground: middle point

I really doubt that is possible, right ?

[bdunham7]

I really doubt that is possible, right ?

In fact that is exactly how it is done.  The only requirement is that the two channels have to be isolated and that is the usual case.  However, there are exceptions to watch for.

[prune]

OK many thanks !

[adam4521]

Allow for leads, clips, adaptors to connect to your projects. If you’re thinking about ‘opamps’, audio or other analogue/measurement type projects you might want to see if you can get a linear one with old-school transformer inside rather than a ‘switching’ PSU.

For breadboarding also consider getting a USB powered module for convenience although take care —the ‘dual rail’ ones are not typically independent supplies. AA battery holders can be quite convenient too.

[themadhippy]

why not knock something up yerself?

[prune]

laziness 

I'm just starting to look into this and trying to make my head around... but it will probably be the next option if I want to keep costs to the minimum

[Hr_Satch]

Hello, yeah, if it doesn't may take a huge bite in your budget,
assemble a dual PSU yourselves.

BUT, OpAmps, often do need more than +&- 5Volts.
AND, it needs to be symmetrical, and at best somehow tracking under Load !

my simplest, best , and ideal limited costs would be two 15V regs. LM7815
and a uA7915 for the negative side. But this isn't Tracking, . . .

And often tracking designs in ANs, are just tracking one rail to the other.
Moreover, they are too often Tracking the Least loaded rail, the Negative one 

Ideally should track both. Otherwise stick to assymmetrical supplied OpAmp applications, LoL

There used to be a rather simple solution to Tracking both rails: an SG-3501 see pict.
But with ALL good things, somehow they come to an end, and get replaces by rubbish SMPS, . . .

Once again: my simplest, and best for the wallet: two complemantary 'fixed' regs in To-220
dual bridge rectifier, some CAPS,
and a convenient dual centertapped secondary transformer with it:
pritty much less noise and distortion.