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Post by tronicgr on Sept 5, 2015 2:57:10 GMT
That looks perfect now. Well done!
Thanks Thanos
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Post by clyevo on Sept 5, 2015 18:37:28 GMT
Thanks for the help thanos, greatly appreciated. However this relay will set me back the progress for 1 month, since i cant buy it locally, need to wait for delivery from china using cheap postal service.
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Post by clyevo on Sept 7, 2015 1:12:19 GMT
You can use separate power supply to power the solid state relay boards, but make sure you wire a ground connection from each back to amc1280usb (or 6dof ext board). The connections you made are fine, except you don't need to connect all the COM of all the VFD together, only every two for Fwd and Rev. Thanks Thanos Thanks thanos, i did not noticed the ground connection mistake on the VFD side. And sorry for the big images probably cause your mobile some bandwidth. I find PNG files are large, so next time i will post JPG files only. Thanos just to clarify, i dont need to connect the 24v power supply to the ext board at all? How the analog 0-10v works without the power? And also i use ULN2803 instead of UDN2981 right?
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Post by tronicgr on Sept 7, 2015 19:55:33 GMT
Thanks thanos, i did not noticed the ground connection mistake on the VFD side. And sorry for the big images probably cause your mobile some bandwidth. I find PNG files are large, so next time i will post JPG files only. Thanos just to clarify, i dont need to connect the 24v power supply to the ext board at all? How the analog 0-10v works without the power? And also i use ULN2803 instead of UDN2981 right? You are right, forgot about it. You need to connect a 24v to power the 0-10V circuit (perhaps try tap that 24v voltage from one of the VFD inverters?). You can remove the ULN2803 or udn2981 power chips as you are using the relays now. Thanks Thanos
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Post by clyevo on Sept 8, 2015 2:36:48 GMT
Thanks tronicgrJust wondering. Is it possible that the COM and GND of my inverter must be isolated according to the manual because of risk of contaminating the GND of +10v analog with noise? Or is it because COM and GND has different potential i.e. maybe not 0Vdc? Because my understanding is GND and COM is ref voltage which is always 0Vdc. Anyone who knows electronic circuit please explain this to me. Its kinda confusing sometimes.
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Post by riton39 on Sept 8, 2015 17:52:27 GMT
I did not understand the interest of this relay card, what is it?
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Post by tronicgr on Sept 8, 2015 19:28:57 GMT
Thanks tronicgrJust wondering. Is it possible that the COM and GND of my inverter must be isolated according to the manual because of risk of contaminating the GND of +10v analog with noise? Or is it because COM and GND has different potential i.e. maybe not 0Vdc? Because my understanding is GND and COM is ref voltage which is always 0Vdc. Anyone who knows electronic circuit please explain this to me. Its kinda confusing sometimes. Its true its should mean 0vdc. But I just checked with multimeter and there is no internal connection between the COM and Ground. The reason is that inside the VFD inverter there are optocouplers for the digital signals that do not necessarily need to be connected to the ground. In some inverters is also possible to leak some current or voltage from the 24v digital input to the analog input if you tie the COM and GND, thus the reason they have them separated for inverters that only have SINK inputs. No problem to tie those grounds together if using source inputs though. Thanks Thanos
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Post by tronicgr on Sept 8, 2015 19:31:36 GMT
I did not understand the interest of this relay card, what is it? Its isolating the SINK inputs of the VFD from the analog input circuitry. Not needed for VFD inverters with Source inputs! Thanks Thanos
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Post by clyevo on Sept 10, 2015 7:46:38 GMT
Thanks tronicgrJust wondering. Is it possible that the COM and GND of my inverter must be isolated according to the manual because of risk of contaminating the GND of +10v analog with noise? Or is it because COM and GND has different potential i.e. maybe not 0Vdc? Because my understanding is GND and COM is ref voltage which is always 0Vdc. Anyone who knows electronic circuit please explain this to me. Its kinda confusing sometimes. Its true its should mean 0vdc. But I just checked with multimeter and there is no internal connection between the COM and Ground. The reason is that inside the VFD inverter there are optocouplers for the digital signals that do not necessarily need to be connected to the ground. In some inverters is also possible to leak some current or voltage from the 24v digital input to the analog input if you tie the COM and GND, thus the reason they have them separated for inverters that only have SINK inputs. No problem to tie those grounds together if using source inputs though. Thanks Thanos The circuit of the 24v is separated from the rest of inverter circuit via optocoupler. The problem is that on AMC1280 extension board, the GND terminal is on the same circuit for both 0-10v analog and 24v digital. I am thinking something like this: The analog signal is leaking into the 24v circuit in small amount accounting for the higher resistance at the 24v circuit? If this is the case then the relay is a really good way to solve the problem. No, actually the only way.
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Post by tronicgr on Sept 10, 2015 15:42:55 GMT
That is what I had in mind too, but I have seen inverters that work fine with the above logic... I guess it depends in the design of each inverter! I guess the only way to be sure is using a relay board in sink inputs VFD inverters. Thanks
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Post by clyevo on Sept 19, 2015 19:56:24 GMT
Solid state relay that i use has high level trigger which most of the time doesnt trigger even the led on the board lights on as it should on corresponding switch. I compared it with manually connecting both ends of wire and there was no problem activating FWD and REV.
Anyone that need to use relay, my advice is to use electromechanical relay and not solid state relay like i bought. Just find out the switch has high voltage drop. I measure the closed relay about 11kohm and the more it switch on and off the higher the temp of SSR and the higher the resistance. Most of the time my inverter cannot detect the closed circuit due to the voltage drop.
So i need to wait again for the conventional good old mechanical relays to arrive...
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Post by clyevo on Sept 19, 2015 20:00:40 GMT
linkyeah so this confirms it, not very good for voltage sensitive input sensor
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Post by clyevo on Sept 20, 2015 10:54:42 GMT
I messed up one of the UDN2981a chip during testing with multimeter, i foolishly connect the A1 (FWD output) to the ground to test the current. I did this because i was trying to measure the current to match the specification of the electromechanical relay that i am about to buy. But I inspect the whole board was ok except for the forementioned chip. You are right, forgot about it. You need to connect a 24v to power the 0-10V circuit (perhaps try tap that 24v voltage from one of the VFD inverters?). You can remove the ULN2803 or udn2981 power chips as you are using the relays now. Thanks Thanos Well if this is true then i can get away with my mistake. So i tried removing both the udn2981 chips but i cannot seem to get the analog signal 0-10v to work even though i connected the 24volt 1A power supply like in the picture below. I also tried different jumper configuration 2-3,4-5 and 1-2,4-6 and also both jumper taken off. Is there any way to get it the analog powered without using the udn2981 chips? What about the GND, +15v terminal at the bottom side of the picture below? Can i use that? Of course if can then i need to purchase a 15v power supply then.
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Post by tronicgr on Sept 20, 2015 13:27:23 GMT
Yes you can use the +15v terminal connector. You can connect +24v to it, no need to use +15v only. The amplifiers use only up to the voltage they need to get 10v analog out. As for the 24v terminal, there is possibility that you burned the trace as well, when burned the chip. Happened to me before with a wrong polarity placed capacitor that exploded. Thanks Thanos
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Post by clyevo on Sept 20, 2015 14:04:05 GMT
Yes you can use the +15v terminal connector. You can connect +24v to it, no need to use +15v only. The amplifiers use only up to the voltage they need to get 10v analog out. As for the 24v terminal, there is possibility that you burned the trace as well, when burned the chip. Happened to me before with a wrong polarity placed capacitor that exploded. Thanks Thanos Thanks thanos, So i can get away without the udn2981 chips? But i ll try the +15v terminal and change the jumper to +15v. Can you check if i burn anything on the trace, coz i see everything is fine.
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