On Friday 28 February 2014 23:37:02 Jon Elson did opine: > On 02/28/2014 12:01 PM, Gene Heskett wrote: > > Isn't that an SSR Jon? How does it turn off then? > > It is a classic optocoupler, good to DC. Crydom and Omron also > make DC SSRs, which I guess are FETs and a photovoltaic receiver > to turn it on. The board I make is good to 15 mA at 60 V, so > purely for signal applications, like turning a VFD on and off. > > Jon
Humm, and its switching speed FFR? The sparkfun gizmo is supposed to do about 4 u-s to on, and 5 u-s to off. That shouldn't be more tan 1% distortion of the pwmgen's output timing since I am presently running at about 120hz for the rep rate, more in deference to the lack of speed in the C-41 than any good and real reason. Certainly no use going much faster when its increments are in SERVO_THREAD units. At 2khz, 120hz rep rate, the steps, before dither are about 6%. OTOH, I probably do NOT have an optimized setup, from the hal file: gene@lathe:~/linuxcnc/configs/my-lathe$ grep pwmgen my-lathe.hal loadrt pwmgen output_type=0 addf pwmgen.make-pulses base-thread addf pwmgen.update servo-thread # setup spindle pwmgen.0 setp pwmgen.0.pwm-freq 120.0 setp pwmgen.0.scale 1500 # sorta like a gain control setp pwmgen.0.offset 0.069 # overcome friction in drive? set s60=1 rps setp pwmgen.0.dither-pwm true setp pwmgen.0.max-dc 0.99 setp pwmgen.0.min-dc 0.001 # min duty cycle .5% or just creeping rpm # then feed output to pwmgen.0.value net spindle-pwm-fixed lincurve.0.out pwmgen.0.value net spindle-switch flipflop.0.out pwmgen.0.enable pid.0.enable mux2.0.sel not.2.in net pwm-out pwmgen.0.pwm parport.0.pin-14-out Comments? Either flavor. Lincurve.0.in is the PID.out, with level gains tweaked for fairly smooth PID.0.in vs motor speeds out. Some of the tweaking is substantially compressed at the high end as the gain vs rpms seems to have a very exponential curve approaching vertical in the top 20% of the speed range I am using. Cheers, Gene -- "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> NOTICE: Will pay 100 USD for an HP-4815A defective but complete probe assembly. ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
