ATO Step Up Step Down Inc focus on selling 1-phase, 3-phase 4kVA to 300kVA isolation transformers, 50VA to 5kVA toroidal transformers and control transformers up to 50kVA. The application plays a pivotal role in selecting the correct transformer. Instances where the typical load may spike must be taken into consideration when selecting a particular transformer. Step- down transformers are designed to reduce electrical voltage. It has less wire turns in the secondary. Thus, decreases voltage.On the other hand, a step-up transformer is used when the secondary voltage is greater than the primary voltage. It has more wire turns in the secondary.