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Products => Test Equipment => Topic started by: PixieDust on September 24, 2021, 03:00:20 pm

Title: Standby Power 3478A & Tektronix 2431L
Post by: PixieDust on September 24, 2021, 03:00:20 pm

Anyone know approximate figures for how much these units consume while off? I don't have a way to test this unfortunately.

Title: Re: Standby Power 3478A & Tektronix 2331L
Post by: AVGresponding on September 24, 2021, 03:16:01 pm

Can't speak to the Tek as I don't own one, but the 3478A uses approximately nothing; it has a hard power button.   ;D

In any case it only uses around 9W when on, with a 0.63 power factor.

Title: Re: Standby Power 3478A & Tektronix 2331L
Post by: PixieDust on September 25, 2021, 03:26:23 am

Thanks AVGresponding :).

As for the oscilloscope, any similar models would do. I would imagine all of the scopes of that vintage would consume similar amounts when off.

Title: Re: Standby Power 3478A & Tektronix 2331L
Post by: bdunham7 on September 25, 2021, 03:42:27 am

If you look at the wiring diagram for any of those scopes, you'll see that the power switch interrupts both sides of the line input and typically there is only a high impedance shunt (470k on the 2432 diagram) inside the power inlet.  So at 220V, you'd have about 450uA and 100mW of power consumption.  AFAIK, that's it.

Title: Re: Standby Power 3478A & Tektronix 2331L
Post by: PixieDust on September 25, 2021, 07:04:44 am

Thanks bdunham7!

Title: Re: Standby Power 3478A & Tektronix 2331L
Post by: Per Hansson on September 25, 2021, 08:28:11 am

Well, except when you have Rifa caps in the IEC inlet filter: then it can go up to around 10Amps, once.  :-DD