The Transformer Upgrade is an item from IndustrialCraft2 which can be used to upgrade a machine's power input rate or tier. Each Transformer Upgrade placed into one of the four right-most slots of a machine will upgrade its EU input capacity by one tier.
One upgrade enables a tier 1 machine to receive 128 EU/t. Two upgrades enables it to receive 512 EU/t, and three for More than 512 EU.
Important: Make sure to put the transformer upgrade into the machine before applying power. Temporarily removing the wiring while setting up your machines is a good way to do this.