Recipe: Redstone Converter
The Redstone Converter can be used to convert regular redstone's power into circuit power and vice versa. Although it looks like a standard full block, in order to provide regular redstone with the correct amount of power it receives from the circuit it cannot be an opaque cube, otherwise Minecraft would solely ask whether the Converter is being powered itself and not is actively powering the redstone.
Currently the texture of the block will not be displayed in the GUI but in the world. I will fix this soon.