I'm trying to build a _DC-DC_ split-rail converter using circuit from [this article][1]. My goal is to split _12..14V_ input voltage into _+2.4V_ and _-2.4V_. To do that, I choosed [LM1501AGR-ADJ][2] IC, calculated the needed inductance value (_15 uH_) and made the coupled inductor, then built the following circuit:

[![enter image description here][3]][3]

It works OK, but only when I apply a certain load. When the load is _1K_ or more, _Vout-_ is about _-11V_, and _Vout+_ is _-0.2V_ (input voltage is _12V_). Load resistance of _220R_ or less makes _Vout-_ equal to _-2.39V_, and _Vout+_ to _2.36V_, which is just fine for my purposes.

I don't like the fact that circuit needs some "dummy" load to work correctly, because it means aditional power consumption. I'm gonna use battery as the power supply, so I whant it to consume as less power as possible. Besides, it looks like a very quick'n'dirty solution. Are there better ways to solve this problem?

To provide some additional information about the circuit, I tried to obtain the inductor's currents waveforms. To do that, I removed _C2_ and _C3_ and applied the load resistors _10R_, than measured the voltage waveform on them. Here is what I got:

[![Primary coil][4]][4]

Primary coil

[![Primary coil - large scale][5]][5]

Primary coil - large scale

[![Secondary coil][6]][6]

Secondary coil

By primary coil I mean the coil which is connected directly to IC.


  [1]: http://www.ti.com/lit/an/slva369a/slva369a.pdf
  [2]: https://static.chipdip.ru/lib/138/DOC004138836.pdf
  [3]: https://i.sstatic.net/LsJLp.gif
  [4]: https://i.sstatic.net/nl5Vz.gif
  [5]: https://i.sstatic.net/w6oDb.gif
  [6]: https://i.sstatic.net/pmih4.gif