hi /diy/ does anybody know how I could make a +5v, -5V power

>>1191579

Buy two 5v supplies and connect the positive side of one to the negative side of the other, and that point is ground.

For opamps there's no need for the supplies to be regulated, but if you care about that you can get nice inexpensive 5v regulated supplies from places like AdaFruit and other places.

are you sure you need +-5 V? many op amps are better off with something like +-15 V.

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>>1191579

>>1191579
center tapped transformer, 2 bridge rectifiers, 2 capacitors

>>1191579
I'd just use an ATX power supply.

>>1191627
do the newer ones (5+years) even have the negative rails?

>>1191632
−5 is optional now. I don't know if most have dropped it.

>>1191637
most still have all the negative rails, you just cant get much power out of it (you are lucky if you can get 200ma from all of them combined)
>>1191605
this

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>>1191605
>2 bridge rectifiers
One is enough when you have a center tap.

>>1191601
That's not what common ground means. The 5V source would have 5K internal resistance.

>>1191579
There's plenty of inexpensive DC-DC converters out there that will do it. I've got a handful of 5vdc to +/-15vdc converters that work great. I just plug in a phone charger and have an *unregulated* +/-15 volts for playing around with. Since they are only a few bucks each, I end up permanently connecting them and running projects off phone chargers all the time. Of course, it also helps that I have several micro-usb boards sitting around.

>>1191627
Would introduce noise. Best ist to use two batteries. 9+9v for example to fiddle wi5h op amp. Not suited for usage just for learning. Noisefree and harmonicsfree voltage source. El. Engineer has spoken.

>>1191605
I'd use 4 capacitors. 4700uF and 100nF for example, large one for 50/60hz filtering and small cap (foil preferably) for HF noise filter. If you know precisely the load you may also add few uH worth of inductor in serie.

Thanks everybody, sorry I wasn't here...

>>1191659
This is what I'm doing btw.

I got a toroidal with two secondary coils, I will connect them and use that node as ground and basically do as per that diagram.