http://cdn.familab.org/blog/wp-conte...84_v0_4170.jpg
im not great with circuits but a quick question i have after lookinga t this one is why would it be illegal in some countries?
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http://cdn.familab.org/blog/wp-conte...84_v0_4170.jpg
im not great with circuits but a quick question i have after lookinga t this one is why would it be illegal in some countries?
I received one in I think in under 10 days, which is no different from shipments I get from the US, actually the Hong Kong ones are among the fastest!!
Al.
Most likely because it mentions EMI requirements and supposedly appropriate testing was not done to confirm if it conforms?Quote:
Originally Posted by timmyb199
I am not sure the opto is a zero crossing switching type, which if not, may help matters to includes one?
Al.
I see now there is a zero crossing circuit added as an input to the PicMicro.Quote:
Originally Posted by Al_The_Man
Al.
which circuit you looking at AL. thanks for all the input on the thread, Im hoping to cut some pcb's early next week. im bummed my bits did not show up todayQuote:
Originally Posted by Al_The_Man
Don't worry and dont afraid guys ..we are not doing bad to SuperPID ..It will always sell because of lot of good options and many lazy people will not build our PID spindle control...
If i set on this project i shall build it less than 03 days with a working prototype... Our PID will not be so much graphical but using 20x4 display we can put a lot on it..including temperature/RPM , humidity or whatever you like...Atleast our PID shall cover external drive PWM acceptance for controlling the PID through MACH3 or EMC etc..
Now we have to keep the name of our PID spindle control driver...
The one you posted in #121.Quote:
Originally Posted by timmyb199
http://cdn.familab.org/blog/wp-conte...84_v0_4170.jpg
Al.
i vote for
O-P-I-D
or pronounced
O-PID
open source pid
:):banana::banana:
I found the code listing for that Pic 16C84 design and it does not have zero cross over switching.Quote:
Originally Posted by timmyb199
Just a choice of either IGBT or Triac switching.
I thought by the print it may have had burst switching to avoid EMI?
Either way it uses phase angle control.
Al.
Just discovered this thread. I've read most of it.
Electronic designs have such a wide range of doing similar things that there is no "best" circuit. Each design has good qualities and some not so good. Often a DIYer picks parts from their junk box and experiments away.
Regarding the zero crossing circuit, I have a preference for an H11AA1, which has two photo diodes inside, and add two 15K resistors to sample the AC line. This circuit would not require a transformer. However, it should be done by peiople who understand the danger of working with 120VAC (or 220VAC in some other countries). An experimenter may still need to add some additional componets for the zero crossing if AC noise is a problem.
Triac selection is somewhat power dependent. I'm thinking of a 16amp unit for my 120VAC source. I may experiment with some ST T1625T-8I that I got from Mouser. I tend to prefer the higher gate current types since I understand that the gate will be less sensative to noise. Again design choices with no "best" one. One may also choose a triac that has the package insulated from the AC line in case a heatsink is needed without getting shocks if you touched the heat sink while operating. Another design choice.
There are numerous manufacturers of triacs that provide design ideas, or application notes, to control motors, light, heaters, etc that you may get additional ideas of what to add. Since a motor will produce voltage spikes, some designers add a MOV (varistor) to clamp these spikes. The selection is AC line voltage dependent.
The thing with zero crossing turn on, is that you have to use the burst type of control for SCR/Triac, as any thing else is phase angle control, i.e.turn on sometime in the conduction cycle, the only thing there is you can guarantee is zero turn off only.
But unfortunately burst control mode, although most EMI free, is not that suitable for decent sized motors.
Al.
Yes, I agree with you, Al.
I also wanted to address the discussion regarding the question if the transformer could be eliminated for the zero crossing detect circuit - and it can. What the Arduino will do with this dectection input is up to the designer. However, I do suspect that this project will gravitate towards a phase angle controller, rather than a burst mode. But it may still be fun to try a burst mode controller.
Sometime ago I had thought of experimenting with a motor controller for my MasterCraft 2.5HP router and have it "crawl" real slow, yeah..., like a stepper motor. Then see what problems I run into, like overheating, or excessive current, poor torque, etc. Then to create a possible solution for each problem. Just to experiment even if I had no useful project for it. It was to be mainly an educational excercise. I still haven't done it yet, but this thread made me revisit the idea now that I bought some triacs for a light dimming project.