Products > Test Equipment
My poor mans SMU - The Agilent 66311B
mark03:
I have a couple of this model's big brother, the 66332A (20V, 5A). They are more of a pizza-box size but have the same wind-tunnel heat sink and deafening fan noise.
You have inspired me to investigate a slower/quieter fan. I would definitely use them more if they weren't so loud.
kirill_ka:
--- Quote from: ve7xen on March 11, 2016, 05:52:01 am ---Wow it's really slow to kick into CC mode with a resistive load! 220ms. My hypothesis is that the loads above would appear as nearly a dead short to the supply, pulling enough current to hit the 'peak' current limiter, and then ending up in CC mode after that. With the resistor, 14V/50R is only 280mA, so it runs that way for a while before the regular loop notices.
--- End quote ---
I know that post is 4.5 years old... I've bought an older version of 66311B (which is called "through hole pcb" in the service manual). Initially I thought that slow switching to CC mode is a fault of my unit. Especially after the seller confirmed that his 66311B is faster. Then it appeared that he was using a newer revision for the test.
While trying to solve the "issue" I found that the main analogue PCB is identical to the HP 66312B. And it does have schematics in the service manual! It looks like HP engineers deliberately sacrificed CC mode in favor of peak current performance. The attached picture shows the main differences in current control circuit.
Shannon:
Could we use those part of this broken 66311B to build a higher power DC supply?
Maybe we can parallel the main power Mosfet or BJT, and modify voltage feedback and current shunt resistors, using higher power transiformer
if somebody has done this work, please give me some advise.
sounds like it's not hard to upgrade, and to get much more powful.
the drawback is we should be clear about those value on display is fake ;D
vaualbus:
I know this blog is olddd
But I need some help. I got my hands on the 66309D model of this supply with some eeprom corruption problem (The DVM measure were not accessible) so I clean the EEPROM loosing calibration but that is not a problem for me. Unfortunaly doing so I also lost my SN and option.
I see in this video of keysight around 1:49 there is a DIAG:SN option to set the SN via GPIB.
I try to write a script but is failing saying it is not liking the serial number format. Apparently it expect something that is not text for parameter?
I am new at pyvisa so maybe I am doing a stupid mistake? :-DD
First enable calibration
foundInst.write(":CAL:STAT 1")
# Send the serial number, it must be sent as ascii
foundInst.write(f":DIAG:SN US39071080")
# Save calibration
foundInst.write(":CAL:SAVE")
# Disable Calibration
foundInst.write(":CAL:STAT 0")
# Close the instrument.
foundInst.close()
Returned error is -148 that for the user manual is: -148: Character data not allowed
Now are there a way to also enable option?
Because I lost both output as I have the option 521 installed so the output are switched using mechanical relays and of course now the isntrument things it has no option so it never turn on the output. (I verify with a multimeter following the SM that the output rails have the correct voltage!)
Hydron:
If anyone is interested, see attached FW image for 663(19/21)(B/D) version 3.01. This is the firmware which supports datalogging as per some other threads, e.g. https://www.eevblog.com/forum/testgear/66319b-firmware-image/.
This came from my 66309D, which was sold "as-is" as a 66319D, with the 66319D firmware, front label and FAKE rear serial number sticker (the real one saying 66309D was still underneath). The price however wasn't high even for what I got vs what it was sold as (about 90 GBP shipped) and it wasn't obviously broken other than lying about the model name so I didn't make a fuss. Some observations about changing firmware and other oddities on my unit:
- The hardware clearly isn't that of a 66319D, as it is missing the extra PCB with analogue multipliers etc used for the output resistance control function.
- Running 66319D FW on a 66309D seems to work for the most part - the 1A range (unique to this model) is broken and resistance setting does nothing. I didn't test the fast datalogging capability but I suspect it will work given there is no difference in the logic/ADC board. This may be of use to those who want the fast datalogging on a model which doesn't support it otherwise, and are happy with losing current autoranging capability (manual range set is still OK if you avoid 1A).
- The EEPROM holding calibration etc is not necessarily compatible between the different FW types (in my case trying 66309 and 66319) - I had to put either a 66309D EEPROM image (thanks "TheSteve" for helping with this) or blank it totally to run the correct 66309D FW, otherwise I was seeing issues like the fan not running.
- After changing the FW or EEPROM image you need to do the initialisation procedure and calibration, and for a blank EEPROM also set the SN as noted here: https://www.eevblog.com/forum/repair/hp-66309d-issues
- My unit had a zero ohm link fitted at R427 (with flux everywhere - clearly not factory), which broke the 20mA range, DVM and 2nd output measurements by stopping the analogue mux which switched these into the ADC input from selecting the right channel. Major WTF as to why this was done, removing the 0R link fixed all this.
- It also had U327 obviously removed - this is a LM311 used for overvoltage detection; replacing it restored this function (another WTF)
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