I have successfully constructed my simple tDCS device and after only 5 days of using it i had a lucid dream that i could attribute to the device but now i have a problem , research shows that you need a oscillating-tDCS device to alter your brain waves along with stimulating the part you wanna stimulate using direct current . (scientists succeeded at inducing lucid dreaming using oscillating tDCS that altered brain waves to 40 hz while stimulating the dlpfc with the o-tDCS device. My device currently only provides a direct current and doesn't have the oscillating capability , does any one here how to modify it to provide frequencies to the current while still providing a direct current that flows from the anode to the cathode , am a med student not an electrical engineer so i don't know how it could be done , any help would be appreciated , and please keep it as simple as possible.