Hello everyone,
I recently bought Hitachi V665 oscilloscope from USA but the thing that bothers me is the sign on the back : 120V only.
So can i plug it savely to 220V power line?
According to service manual the working range is 90-250v AC. It uses STK7308 switching regulator and after it its switching transformer.
I dont want to spend additional money for stepdown transformer. What to trust service manual or the sign?
Thanks
I don't know anything about you specific oscilloscope, but the service manual may be for a range of models. And not your specific variation of the oscilloscope.
I would trust what it says on the scope.
Again according to service manual all these models share the same power supply circuit V-1065A-V1060-V665A-V660
I dont see any indication that it cannot work with 220V AC line but i'm not 100% sure so that why i'm asking for advice
Datasheet for STK 7308 says 80-280V btw.
Further more looking at the schematic there isn't 120V/220V statements . So i'm thinking the whole thing is just different labels for different countries.
I'm not familiar with this particular Hitachi scope, but my lower end one is multi voltage and the voltage is selected by the orientation of the fuse holder, but of course, the correct fuse type must be used. Does yours have this or similar?
Thanks Steve30, no it doesn't have anything like that, but I took the risk and trusted the service manual despite it says 120V only and powered it up with 220V AC main, guess what it powered up nicely .
Mistery solved, I saved up ~20Euro for nothing and the noise that step down transformer will add to this instrument.,(this isn't a hair dryer)
I dont blame the japs, more likely the yankees for that label on the back, because their certification system back then, this is old instrument.
I will change the fuse for 250V rated one.