Agilent U8001A encoder

[radar_macgyver]

Hello all,

Not sure of forum rules - so I figure I'd post this and mods can move/delete if it's not the right place.

I have an Agilent U8001A power supply, which has a broken control knob. It allows me to decrement a parameter (voltage/current) but increment is very jumpy. I opened it up and probed the quadrature encoder outputs. Sure enough, one of them was noisy (transitions were not clean). I managed to get the part off the board, but there was little to identify it. After some searching on Digikey, I found the part: it's a Bourns PEC16-4015F-N0024. I'm going to replace it with a PEC16-4215F-N0024, which is the same thing but with detents (I dislike encoders without detents). Wow, can't believe Agilent used such a cheapie encoder on this supply!

Hope this helps someone else who has similar issues.

[HighVoltage]

Thanks for this part number.

Encoders have been a problem in Agilent gear for a long time in power supplies and signal generators and, well almost anything.
Sometimes you just open them and clean them and they will work perfectly again.
But most of the time, I have replaced them as you have.

I think one of the reasons they break is during shipping of a used unit and it gets hit a little on a turning knob.
Because I bought several Agilent instruments used and the seller claimed that the knob was working perfectly before shipping.
But it is always an easy fix.