DC circuit breaker and load voltage regulation are refers to the transformer tap switch adjustable voltage. The difference is no excitation voltage regulating pressure switch does not have the load capacity of gear conversion, because the switch in the gear shifting process, short time off and disconnect the current load will cause contact pull tap switch or short circuiting of the arc burn, so shifting must make transformer outages. So for the voltage requirements are not very strict without transformer often diaodang. And load tap changer can load switch gear, because of on load tap changer in the shifting process, there is no short-term disconnections, after a transition resistance transition, from one file to another a file position, thus there is no load current breaking open the arcing process. Generally used for voltage transformer often need strict diaodang.