On Wednesday 03 February 2016 09:27:58 Gene Heskett wrote: > On Wednesday 03 February 2016 04:26:07 Erik Christiansen wrote: > > On 03.02.16 03:11, Gene Heskett wrote: > > > So the only way to do this relatively non-timing critical psu > > > switching is to use the carge pump, and a charge pump detector to > > > do that control, it can absorb the noises without triggering the > > > outside world for 1/4 second while its getting its shit in one > > > sock. > > > > > > A crapload of such problems could be avoided if the 5i25 failed to > > > a logic zero, same as powered off, when its disabled. > > > > Now I'm not grokking the problem, Gene. The first component in a > > simple charge pump is a capacitor, so the DC state of an inactive > > input is quite irrelevant. Unless the input is hopping up and down, > > there's no charge pumping possible - that's what it's designed to > > detect, after all. > > > > Erik > > Huh? Have I not explained in enough detail? > > I have a charge pump, running at servo-thread, so its square wave is > nominally 500 Hz for a 1 kilohertz servo-thread. > > From my .hal: > (word wrap off) > > loadrt timedelay names=delay-soft,pwr-off-delay > loadrt charge_pump Sorry, I missed this in my hal file snips: loadrt and2 names=and.vac,and.lube,and.spndl-pwr,and.spndl-soft > addf charge-pump servo-thread > addf and.vac servo-thread > addf and.spndl-pwr servo-thread > addf and.spndl-soft servo-thread > addf delay-soft servo-thread > addf pwr-off-delay servo-thread > setp charge-pump.enable true # just leave it running. > setp pwr-off-delay.on-delay 1 # seconds, quick on > setp pwr-off-delay.off-delay 12 # seconds, slow off so resistor is > in circuit by then setp delay-soft.on-delay 10 # seconds delay > till the 51 ohm is SSR shorted setp delay-soft.off-delay 2.0 # > seconds in case I have it bass ackwards setp > hm2_5i25.0.gpio.011.is_output true > net spndl-power motion.motion-enabled pwr-off-delay.in > delay-soft.in and.spndl-pwr.in1 setp hm2_5i25.0.gpio.011.is_output > true # pin J3-8 > net start-spdnl-pwr and.spndl-pwr.out hm2_5i25.0.gpio.011.out #pin > p3-8 net spndl-power-on <= delay-soft.out => and.spndl-soft.in1 # > crowbar resistor # set up this output on p3-09 for soft start > bypassing > setp hm2_5i25.0.gpio.012.is_output true #is p3, bob pin 9 > # that sets gpio.012 to output, and this crowbars the soft start > resistor net spndl-power-soft and.spndl-soft.out > hm2_5i25.0.gpio.012.out #P3 pin 9 > > So when enabled by the time-delays, both pin 8 and pin 9 on the db25, > p3 on the 5i25, are being pumped by the charge pump module. > > In an outboard box, bonded to the main box, is a teeny power > transformer feeding a small bridge and filter capacitor to make about > 34 volts out of a 12-0-12 winding rated at 200 mils. > > This feeds a buck switcher to knock it down to 12 volts, regulated. > I could adjust it as high as 30 volts, but 12 does the job. > This +12 volts is tied to the SSR's + control terminals. > > Cobbled up on a radio shack project board in that box are 2 charge > pump detectors. > > When they have seen the pump signal long enough to charge up the > output capacitor, cF, the gate of a mosfet is driven high enough to > turn the mosfet on. > > The schematic for the detectors is attached, drawn in geda, not eagle. > > Those 2 pumping signals are sent to the 2 pump detectors, with the > drain of the mosfet output transistor of each connected to the SSR's - > control terminals. > > The net result is that the first hexfet to turn on, enables a 40 amp > SSR to connect the hot leg of the input power to the primary's of all > 4 tordoid transformers THRU a 51 ohm 200 watt resistor to limit the > inrush surge that was tripping a 20 amp breaker in the service box. > > The delay times are such that nominally 10 seconds later, after the > filter capacitors have charged well, the second signal starts pumping > too, and that pump detector then turns on the second SSR, putting a > crowbar across that 51 ohm resistor. > > In the .hal setup shown above it should also turn off by first turning > off the second SSR so that the resistor is restored to be in series > with the transformer primaries, and about 3 seconds later, the first > SSR is also turned off, disconnecting power from the toroids > completely. > > But, if my clicking on either of the 2 upper left axis buttons to > disable the machine, also kills the 5i25's ability to output those > pump signals, which I now suspect to be the case simply because > nothing else makes sense, then the SSR's will be turned off quickly > with zero regard for the off timings set in the .hal pastes above. If > the main one goes down first, with the crowbar still enabled, I can > see some odd goings on. > > So when I have injected some starter fluid, aka coffee, and go to the > garage to check, the first thing I'll do is see WHEN the pumps stop. > And I'm betting they stop, going high & staying there, the instant I > click on either button. > > Now, does this explain it? Something is killing a 20 amp breaker when > I click on the axis disable buttons. NOT after the timeouts set in the > .hal. A 30 amp breaker survives the surge with all this stuff > bypassed. But a 30 amp, feeding a 4 plex, even if 10/3wg is used to > feed the 4-plex, is still sick bird according to the NEC. And my fire > insurance claim will be null and void. > > If the resistor crowbarring SSR goes off first, problem solved. > > So changing out those cobbled up chargepump detectors for the new ones > with schotkey diodes, improving the hexfet drive and doubling the cF > in the one driving the first SSR will make sure that even if its only > for 2 or 4 cycles of the 60 cycle power, the desired off sequence will > be maintained such that the resistor is restored to the circuit before > the main one goes off at the next zero crossing after its turned off. > > If that sequence can be established, the turnoff will have the > resistor already in circuit to control the surge. > > Am I making sense, or blabbering into a bowl of morning oatmeal? > > Now, to go check this theory. I'll post later when its been confirmed > or disproved by my ds201. Its there, plugged in to keep it charged.
Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
