6n137-I, seems to be half price (half frequency also) and positive output, but I do not think we need that super speed. We have only 20kHz in PWM speed... (wanna change that? )
http://www.tme.eu/ro/Document/71c7b9...e816/6n137.pdf
Mihai
6n137-I, seems to be half price (half frequency also) and positive output, but I do not think we need that super speed. We have only 20kHz in PWM speed... (wanna change that? )
http://www.tme.eu/ro/Document/71c7b9...e816/6n137.pdf
Mihai
I must admit I do not get this very well... You mean we could use a couple of those to drive directly the low and high side of a half bridge without using any other dedicated circuitry? How do they work? We do not need a Higher voltage for high side?
Hmmm... I do not get it... please elaborate with a schematic... could we drop the ir2101s?
Thanks
Mihai
I must thank here to the user tivoidethuong who offered to give me for free a DC motor for testing. Thanks again! I appreciate it. You can make a special request for the code ))
I just bought from ebay a used servo. Dunkermotor GR42x25 mit Getriebe PLG 32, i=6,25:1, 12V-24V/DC, 3600 U/min | eBay
I think it will do just fine for our DC motor testing. I will add DC motor support after I will receive it... I presume nothing will change in the schematic... so go ahead with your designs...
Please do not forget to add a jumper from PB1 to 3.3V for the bootloader...
Mihai
I do not think we can add the type K termo sensor directly to the ADC.
From what I understand from this picture: https://en.wikipedia.org/wiki/Thermo..._functions.svg
we have a variation of 10mV for 250 Celsius... our ADC is 12 bit with VRef set to 3.3, so this gives us o theoretical resolution of 3300 mV / 4096 = 0.71 mV... not very good for measuring a few milli Volts... So we need to amplify that signal...
Mihai
about opto mosfet gate drive
1. bostrap like ir2101
2. independent 15V voltage source for high side
Hi,
if its not possible to read the K-sensor directly with the Arm it will be not a problem to insert a special operationamplifier ic. I do not know the manual from the ARM but some microprocessors have integrated programmable gain for some of the analog inputs. For the power pcb I will use a integrated bridge IRAMX20up60a there the mosfetdriver built in.
Hans
if you are use iramx20up60a, i dont think HCPL3180 suitable
6n137 is good choice
opto for direct mosfet gate drive
Isolated Gate Drive Optocouplers
opto for IPM interface
IPM Interfaces
about positve ON or negative ON, you can modify stm32 code
tivoi
From what I know there is no way to set the gain in the STM32F103 ADC (old ATMega644 that I am familair with had such features). And since we need the Vref to be at least 3.3 V in order to measure the used current as good as possible we can not decrease Vref. So you need to boost the signal from the K Thermo in order to measure it good. But by the way... Do you intend to something with the value measured like limit the current and stuff? or you just want to stop the circuit on overtemperatures?
Mihai
Hi Mihai,
only stop at overtemperature. This feature must not work from the first time, but its easier when its possible in the pcb.
Hans
Instead of trying to read the thermocouple directly or trying to make an amplifier to be able to read it, wouldn't be easier to just use a MAX31855K chip?
i recommend use dido for temp protec
Capgo - Semiconductor Temperature Sensors
The TIL191 and TIL192's appear to be obsolete... Does anyone know a current part number? I'm trying to figure out the total BOM cost.
James hosts the single best wiki page about steppers for CNC hobbyists on the net:
http://www.piclist.com/techref/io/steppers.htm Disagree? Tell him what's missing! ,o)
James,
I believe Newark still has the TIL191:
TIL191 - Buy ISOCOM TIL191 Online at Newark element14
Jeff...
Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.
James hosts the single best wiki page about steppers for CNC hobbyists on the net:
http://www.piclist.com/techref/io/steppers.htm Disagree? Tell him what's missing! ,o)
i thinks til191 can replace by pc817
http://www.sharpsma.com/webfm_send/1092
Hi,
here is my next pcb from the controlpcb. I hope the thermosensor type K can connect to the opamp. For current sensing the arduino isolated modul can be used. The power pcb comes soon, I will it use for variable frequency drive and the servo drive. The vfd is a project in the german microcontroller forum.
Hans
Hi,
here is my first design from the power pcb. Hi Mihai its possible to use a pin from the to switch the power bridge on or shut down?
Attachment 296626
Hans
Hi Mihai,
I think B0, B1, B10 or B11.
Thanks
Hans