Shopping for a Lab PSU, BK Precision 9111 - Page 1
Forum section: electronics / testgear

author: CraigHB
author_rank: Regular Contributor
timestamp: November 20, 2016, 04:39:09 am
content: Looking to buy a better benchtop DC supply. I have a couple projects I'm working on where I need at least 50V DC and the one I have only goes up to 32V. I'd also like more power than the one I have. I need to replace it anyway because it's just a cheapo and it's having problems now after a few years of use.I want to go with a name brand this time instead of a cheap Chinese job. When you start getting into higher power and higher voltage these supplies get expensive quick. The best value I've found in a supply that can provide the power and voltage I need is the BK Precision 9111 with a max of 60V, 8A, or 180W whichever comes first. That's the multi-range which is a really nice feature. It's also a nice compact size and offers the best bang for the buck I can find. I understand it's a switch mode power supply which means output is not as clean as a linear supply. All my supplies so far have been linear.I can't find much on the BK Precision 9111 lab PSU here on the forum. Is this one a good supply? Is the noisier output of this switch mode supply or any other difference from linear going to be a problem for anything?

author: nctnico
author_rank: Super Contributor
timestamp: November 20, 2016, 12:53:46 pm
content: The cheaper switching power supplies can output a lot of EMC noise at the outputs but I don't know how the Itech/BK precision models behave.I'm also looking for a new power supply and the GW Instek GPE-2323 (2x 32V 3A) has made it to my shortlist because it is cheap and it has accurate current readout (1mA). A PSU from Rigol or Siglent would be much more expensive for the same readout accuracy.

author: CraigHB
author_rank: Regular Contributor
timestamp: November 20, 2016, 02:16:12 pm
content: That Rigol would be a good one in terms of price range and quality, but I really need the higher current output. That BK one can put out 8A at lower voltages. I need something similar to that. That GW one might be good since the dual outputs can be arranged for higher voltage or higher current. It's also inexpensive. Any other suggestions for something that won't break the bank? Probably 50V and 5A would do.

author: CraigHB
author_rank: Regular Contributor
timestamp: November 21, 2016, 02:50:13 pm
content: Quote from: blueskull on November 20, 2016, 07:17:27 pmThat would be a good way to get more current output with lower voltages which is actually something I could use. Might be something I could do for the times I need it which would not be that rare. At this point I use a high drain LiPo battery when I need currents greater than my supply can provide. Usually it's for the motor controllers I build for my model aircraft. It's a lot better to use a lab supply when testing since it provides the ability to limit current. Those batteries can fry stuff pretty good when something goes wrong.I probably will get that B&K 9111. It should meet my needs. Spent some time looking for reviews on it, not much out there. There are some reviews on the 9110 which is the 100W version compared to 180W for the 9111. There are some negative comments like slow start-up response and overshoots with low current settings in CC mode. That's not something that will affect me I don't think, but the slow start-up rise time could be a bit of a problem. Otherwise it has pretty clean output. I expect it's still a lot better than the cheapo programmable supply I'm using right now. I'm trying to avoid buying something cheap that may break down after some use. My problem with one I have is the user interface has gone wonky, it's not reacting to button pushes correctly. It did work well for a few years though.I have one of those super cheap linear supplies with 60V/3A as well as the low quality 32V/5A programmable one I'm looking to replace. On that 60V/3A cheapo the pots got all jumpy after some use. I managed to take it apart and clean the pots, now it's working well again. I can use that one in addition when I need two outputs. The multi-ranging of the B&K 9111 will be a big help since there are times when I need those higher currents at lower voltages. Name brand supplies with similar outputs get cost prohibitive for me pretty quick. The B&K one is probably the cheapest that can put out currents like that. Though it comes from a China company, it does seem to be pretty well made. At the least it's built a lot better than the one it will replace.