It’s called 12 volt square wave, Or pulse width.
The Snow dose some neat stud in that on the MPG max it has three modes of operation,
1st is the EGT control mode , it will monitor EGT and if the EGT climbs to a given temp, or the rate of climb , (called a delta curve) gets to quick , it will start to apply water , and up the rate of application , until the EGT is controlled.
2nd it has a mile per gallon mode when it applies a very small about of flow during the cruise , this improves fuel economy, you set the low and high of you cruise habits
3rd is the power mode , where it comes on at a given amount of boost , this is a higher amount of water ,for hp