HP 6632A 20V 5Amps Programmable PSU - Page 1
Forum section: electronics / general

author: T4P
author_rank: Super Contributor
timestamp: June 23, 2012, 05:15:47 pm
content: Just saw one on ebay for 100USDIs it worth the money? For a second PSU

author: bingo600
author_rank: Super Contributor
timestamp: June 23, 2012, 07:41:31 pm
content: I have 2 6632B's , i think it's the same model but with a VFD instead of LCD.They are super precise , and can sink & source current.The meters are/were the most accurate i had when i bought them.So i ended up buying an Agilent 34401A DMM , just to verify & calibrate them.All in all my best PSU's , but a bit noisy. (As in more than a Rigol scope)I actually ended up getting & repairing a HP E3610A , for doing longtime tests on voltage ref's.That one has no fans ....But i wouldn't miss out on my 6632B's , i just don't want them on 24/7 for longtime tests./BingoPs: I just saw it- I guess "No postage"Nice price .....

author: bingo600
author_rank: Super Contributor
timestamp: June 23, 2012, 07:54:45 pm
content: I wrote a GPIB-program for my Prologix , to characterize/profile the PSU's on my new Agilent 34401A.And the result is rather nice , gpib is stepping the voltage from 0..20v in 100mV steps , and reading the voltage from the 34401A.Attached are 2 excel sheets of the results ... Deviation from center (gpib specified/programmed voltage)I got an Agilent & a HP 6632B , and one can cleary see that Agilent modified the firmware in the newer Agilent model. See how the voltage ramps up , instead of the "random on the HP"/Bingo

author: T4P
author_rank: Super Contributor
timestamp: June 23, 2012, 08:14:18 pm
content: Nice. Actually so as to speak i don't really want a linear power supply, i know HP can do a good job of a switching supply so i don't want a linear supplyNot that i am not open to options ... but i can't find a HP linear supply sold locally for less then 150$ ...So yeah, 6632 it shall beThanks guys,Dave

author: bingo600
author_rank: Super Contributor
timestamp: June 23, 2012, 08:19:24 pm
content: Ehh ....The 6632 is linear/Bingo

author: T4P
author_rank: Super Contributor
timestamp: June 23, 2012, 08:52:24 pm
content: Quote from: bingo600 on June 23, 2012, 08:19:24 pmIT IS?! WOOHOO! I didn't read the damn manual completelyStupid me that i keep assuming blindly

author: bingo600
author_rank: Super Contributor
timestamp: June 23, 2012, 10:03:34 pm
content: Btw:The excelfiles above , shows the inaccuracy max 4mv , when setting the voltage.rom 0..20vThat is NOT ripple/Bingo

author: aghp
author_rank: Regular Contributor
timestamp: June 24, 2012, 12:03:04 pm
content: Quote from: DaveXRQ on June 23, 2012, 08:52:24 pm(6632B and others in this serie) It is very fast regulating and low ripple and good programmablelinearsystem power supply. It have also sink and source capability. It can be constant voltage, constant current source and it can also be CC or CV load. And you know it is not only "set voltage or current" it also really measure. You can read it via RS232 or GPIB. Example you set it to constant current load and then you read voltage. You can also quite fast step it to different settings. Example drive stepping ramp and read how DUT reacts. It ihave been widely used in manufacturing industry for product tests in product line. (I know one place and they have used n x thousends of these.maybe you have not even open manual - as usual.6632A and 6632B are littlebit different and last produced units are with Agilent name.(there is also precision model available in this serie)Normal "as is" prices without test posibility is around 100-150 and all understand that documented and trusted good condition it is more. Price is low ONLY becouse markets are overloaded with this. And becouse it is not so handy on the hobby lab table. (not useable) But who really need (and understand its guality and features), it is very cheap if look quality.One disadvantage is if think normal hobby use as "lab power". It draw power also without load and fan is like turbine. (there is wind "tunnel" inside end stage.)

author: T4P
author_rank: Super Contributor
timestamp: June 24, 2012, 04:05:08 pm
content: I can go down the store and test

author: nctnico
author_rank: Super Contributor
timestamp: June 24, 2012, 04:53:33 pm
content: You could try and modify it to put 4mm banana plugs in the front. And while the case is open you can put a temperature controlled fan drive circuit in the PSU. I have a HP6002A power supply which I modified to adjust the fan speed based on the temperature. Its starts the fan when the heatsink is over 40 deg. C. With small loads its absolutely quiet. When loaded it spins the fan as hard as required to keep it cool.

author: aghp
author_rank: Regular Contributor
timestamp: June 24, 2012, 06:10:01 pm
content: 6632B have intelligent control (butOP was about 6602Aso this is littlebit OT). 6632A have totally different Fan control (if I remember right it is just fixed speed)Not recommended to modify 6632B, exept fan noise can reduce by isolating mechanical noise from ball beared Fan and maybe changing Fan to model what have more modern aerodynamical design related to airflow noise. But this kind output stage produce very easy some heat even if there is no load (it is very interesting design). I do not know 6002 model how it is designed. maybe the output stage is totally different case.Here attached 6632BFan control.

author: T4P
author_rank: Super Contributor
timestamp: June 25, 2012, 04:03:36 am
content: In any case, i do not mind fan noiseMy metallica's always on full blast

author: bingo600
author_rank: Super Contributor
timestamp: June 25, 2012, 06:49:48 pm
content: I stumbled across this for the 6632BIt Sckz that you have to do it @ every PwrOn , and your PSU might run hot.But it exists ....Quote