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Emerson LPS-10x-M Alternatives

Started by Tim Wescott April 9, 2013
On Sat, 13 Apr 2013 21:33:03 -0700, josephkk
<joseph_barrett@sbcglobal.net> wrote:

>On Wed, 10 Apr 2013 10:11:36 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Wed, 10 Apr 2013 08:37:19 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Tue, 9 Apr 2013 21:59:16 -0700 (PDT), Bill Sloman >>><bill.sloman@ieee.org> wrote: >>> >>>>On 10 Apr, 13:08, John Larkin >>>><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: >>>>> On Tue, 09 Apr 2013 21:43:44 -0500, Tim Wescott <t...@seemywebsite.please> wrote: >>>[snip]. >>>>> >>>>> >When the motor starts to draw power the motor rail drops: when it drops >>>>> >down to match the power supply voltage things are switched on again and >>>>> >it draws power from the supply. >>>>> >>>>> That sounds a little tricky. You could just hang an active zener across the >>>>> power supply output to clamp at, say, 25 volts. That might keep the ps from >>>>> crowbarring, too. >>>>> >>>>> I'm sure Jim would be delighted to design an accurate, 10 amp active zener >>>>> circuit for you. >>> >>>More demented snarkiness. >>> >>>But rather trivial to design, even with off-the-shelf discrete's... >>>think a TL431 plus a power PNP. >> >>Show us. > >Crikey Larkin, even i can see how to do that. Just how dumb are you? > >?-)
What can you say... John "snarky demented NOLA white trash" Larkin always responds that way. One of Slowman's "peers" >:-} ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
On Sat, 13 Apr 2013 21:33:03 -0700, josephkk <joseph_barrett@sbcglobal.net>
wrote:

>On Wed, 10 Apr 2013 10:11:36 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Wed, 10 Apr 2013 08:37:19 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Tue, 9 Apr 2013 21:59:16 -0700 (PDT), Bill Sloman >>><bill.sloman@ieee.org> wrote: >>> >>>>On 10 Apr, 13:08, John Larkin >>>><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: >>>>> On Tue, 09 Apr 2013 21:43:44 -0500, Tim Wescott <t...@seemywebsite.please> wrote: >>>[snip]. >>>>> >>>>> >When the motor starts to draw power the motor rail drops: when it drops >>>>> >down to match the power supply voltage things are switched on again and >>>>> >it draws power from the supply. >>>>> >>>>> That sounds a little tricky. You could just hang an active zener across the >>>>> power supply output to clamp at, say, 25 volts. That might keep the ps from >>>>> crowbarring, too. >>>>> >>>>> I'm sure Jim would be delighted to design an accurate, 10 amp active zener >>>>> circuit for you. >>> >>>More demented snarkiness. >>> >>>But rather trivial to design, even with off-the-shelf discrete's... >>>think a TL431 plus a power PNP. >> >>Show us. > >Crikey Larkin, even i can see how to do that. Just how dumb are you? > >?-)
I want to see Thompson do it. He sometimes does hilarious stuff when he goes off-chip. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
On Tue, 09 Apr 2013 17:37:22 -0500, Tim Wescott <tim@seemywebsite.com>
wrote:

>So, I'm working on a motor drive board for a customer. Due to a desire >for performance improvements within the existing space, we're going from >the traditionally-accepted brute-force power supply to a switcher. > >I have this nice board and software set that's carefully designed to >treat the power supply with kid gloves -- and it works very well with the >power supply that we used for prototyping. > >But for space reasons they went out and found what appears to be the >smallest possible power supply with the apparent specifications needed >(24V and 10A): > >http://www.powerconversion.com/assets/lps200-m_ds_1226129797.pdf > >It's not that this power supply sucks, per se. It's just that things >that work just fine with the original supply (A TDK/Lambda SWS300-24) >make the Emerson supply either exceedingly unhappy or downright dead. >Worse, I'm not sure what's taking out the power supplies. > >So -- > >Does anyone have any mileage with these Emerson supplies? After I told >the customer "why yes, that should do" I began to notice the name >"Emerson" on this group, and the view of their stuff seems to be pretty >dim. I'd like to know if you feel these are OK, or comprehensively bad, >or what. > >Also, I've carefully designed things so that any time the motor is >generating the power goes into a resistor and not into raising the motor >supply rail (and thus backfeeding the supply). But I did notice that >doing so kills one of these Emerson supplies (the TDK supply mostly takes >it in stride, or if you're really egregious about things it turns off >until you cycle power). > >Do you know of anything else that would kill one of these supplies? >While I've eliminated the backfeeding problem, the board still has a >current draw that can vary from a few tens of milliamps to ten amps over >the space of less than a second -- if it would make the supply happier I >can change this so that whenever the motor is turning the board is always >drawing some minimum power. Efficiency will suffer -- but we're not >after efficiency, we're after performance in a small space. > >Also, if anyone knows of a supply that's the same size or not much >bigger, but comes from a manufacturer that's known to make bulletproof >stuff, I'd appreciate it.
I suppose Thompson has dried up on ideas, so consider this: https://dl.dropboxusercontent.com/u/53724080/Circuits/Power/BackFeed.JPG -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation