I built a Royer oscillator using MJH6287 BJTs, adding a load that draws more than about an amp causes it to stop oscillating, any idea why that might be? It should work as a clock, and driver for a FET based inverter like it is, but the BJTs it has should be able to handle enough power for this specific application by themselves.

 

I may have figured it out: the more winds on the control coil, the more current it will put out before cutting out, I am concerned about overvolting the base of the BJT tho.

 

Seems like the value of the resistors also changes the output, more ohms means less output, and less standby current, but too few ohms makes rounded waves, more control coil winds squares up the waves, and increases output, but can drastically increase standby current, increasing the frequency by having less primary winds also increases the drive current a lot, and reduces output. Seems like this design wants a core bigger than I can usually find in ferrite to get the drive frequency low enough to use the transistors efficiently, I do have electrical steel ring cores on hand...

 

Steel ring core running around 370Hz seems to work well. 14 winds for the primary, 17 for the control coil, 500ohm resistors seems to work well for both the ferrite core, and steel core.

 

Normally in an inverter circuit there is more bias applied to the bases. I see no intentional completion of any base current return path.
Also, since what we see appears to be only a partial circuit, there is no reason for any guesses.