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Topic: Really universal soldering controller (Read 818194 times) previous topic - next topic

Re: Really universal soldering controller

Reply #5445
It'll work fine as long as DC side of the aux supply is directly referenced to the circuit GND (not earth).

Re: Really universal soldering controller

Reply #5446
If aux supply is 10~15VDC, Q13 also can be removed and bridged, D14 removed and bridged, R19 removed. R20 has a rather large resistance, something like 22~47 Ohms would be enough to suppress driver noise.
When making changes, Please make them correct, do not modify that Schematic to cheap design ( profit purposed or economy ), If you want changes - replace it with something other.
R20 - current limiting for mosfet drv, regulate power dissipation of Q13

Re: Really universal soldering controller

Reply #5447
Those parts are required for a higher voltage input and it's a robust design. If input is limited to nominal 12V, they can be dropped to simplify the power stage.
Nominal quiescent current of TC4428 with 3V input - 4.5mA, which means voltage drop of around 1.5V on R20. When nominal input voltage is 24V, it's not a big deal, but with the input voltage of 12V this is significant drop. Though, it's proved to be working fine on 12V supplies in C210 configurations. 330 Ohms is really huge resistance for that application and it's not limiting driver current, since it is directly provided by C19. I believe it's there for decoupling.

Re: Really universal soldering controller

Reply #5448
Those parts are required for a higher voltage input and it's a robust design. If input is limited to nominal 12V, they can be dropped to simplify the power stage.
Nominal quiescent current of TC4428 with 3V input - 4.5mA, which means voltage drop of around 1.5V on R20. When nominal input voltage is 24V, it's not a big deal, but with the input voltage of 12V this is significant drop. Though, it's proved to be working fine on 12V supplies in C210 configurations. 330 Ohms is really huge resistance for that application and it's not limiting driver current, since it is directly provided by C19. I believe it's there for decoupling.
What about voltage jump - 2-3 times, do you think its regulation is enough by simple zener and at the same time to supply properly needed current not only to the driver but also to other devices may be added later ( isn't that the purpose of the change ),  everything that, on the price of cents for extra linear stabilization - simple and cheap

Re: Really universal soldering controller

Reply #5449
What about voltage jump - 2-3 times
For the driver? It doesn't really matter as long as the driver output voltage is enough to fully open the MOSFETs (and not exceed maximum driver supply, obviously).
Zeners left there to act as suppressors to protect the driver and the converter.
It's not about the price. Fewer parts mean less hassle to put it all together, less space required. If it would reduce the BOM, even better.

Re: Really universal soldering controller

Reply #5450
It'll work fine as long as DC side of the aux supply is directly referenced to the circuit GND (not earth).
Which means aux supply and main supply shares the common GND? (like 0-12-48v)?

Re: Really universal soldering controller

Reply #5451
For the driver? It doesn't really matter as long as the driver output voltage is enough to fully open the MOSFETs (and not exceed maximum driver supply, obviously).
Zeners left there to act as suppressors to protect the driver and the converter.
It's not about the price. Fewer parts mean less hassle to put it all together, less space required. If it would reduce the BOM, even better.
Everybody bears their own responsibility for what is made on his board. I just can claim - that way is not the proper one to do it. The original design is much, much better and you can keep it without changes, compared to that, or recalculate the current to correspond to the lower voltage.


Re: Really universal soldering controller

Reply #5453
Why it should be a problem? Just to clarify, if the main supply is SMPS, aux supply is also SMPS, if the main supply is a mains transformer, aux supply is a separate (floating) winding in it. Supplies GNDs, of course, should be tied in one and only one point closest to the power input.
Original JBC stations is done in this particular manner.

Re: Really universal soldering controller

Reply #5454
Why it should be a problem? Just to clarify, if the main supply is SMPS, aux supply is also SMPS, if the main supply is a mains transformer, aux supply is a separate (floating) winding in it. Supplies GNDs, of course, should be tied in one and only one point closest to the power input.
Original JBC stations is done in this particular manner.
I was think about the scenario when the main supply is toroid transformer while aux supply is SMPS.

Re: Really universal soldering controller

Reply #5455
I was think about the scenario when the main supply is toroid transformer while aux supply is SMPS.
Why you do speak for that at all, In electronics ( physics ) there is a concept for the potential difference and if you connect ( root them together ) the negative wires of two ( many ) different sources they will share the same circuit, potential differences, and will bring their ​own noises to the shared network

Re: Really universal soldering controller

Reply #5456
I was think about the scenario when the main supply is toroid transformer while aux supply is SMPS.
Should also work, but may bring the same earth related problems as the main SMPS supply would.

Re: Really universal soldering controller

Reply #5457
Hey all!

I'm currently stuck and could use some help figuring out this firmware uploading. I'm using a PICKit3, the latest version of the Firmware published on github, Ver. 5.5 of the MPLab IPE. I'm able to connect to my PICKit fine, but when I try to connect to the PIC32 on the board, I receive this error:

' Currently loaded firmware on PICkit 3
' Firmware Suite Version.....01.56.09
' Firmware type..............PIC32MX
' Too much current has been drawn on VDD. Please disconnect your circuit, check the CLK and DATA lines for shorts and then reconnect.
' Programmer to target power is enabled - VDD = 3.250000 volts.
' Too much current has been drawn on VDD. Please disconnect your circuit, check the CLK and DATA lines for shorts and then reconnect.
' Unable to connect to the target device.
' Failed to get Device ID

I've tried to verify where I can that there's no shorts or cold solder joints, but without the board I'm sure theres parts I missed. Any help would be very appreciated!

Re: Really universal soldering controller

Reply #5458
Hey all!

I'm currently stuck and could use some help figuring out this firmware uploading. I'm using a PICKit3, the latest version of the Firmware published on github, Ver. 5.5 of the MPLab IPE. I'm able to connect to my PICKit fine, but when I try to connect to the PIC32 on the board, I receive this error:

' Currently loaded firmware on PICkit 3
' Firmware Suite Version.....01.56.09
' Firmware type..............PIC32MX
' Too much current has been drawn on VDD. Please disconnect your circuit, check the CLK and DATA lines for shorts and then reconnect.
' Programmer to target power is enabled - VDD = 3.250000 volts.
' Too much current has been drawn on VDD. Please disconnect your circuit, check the CLK and DATA lines for shorts and then reconnect.
' Unable to connect to the target device.
' Failed to get Device ID

I've tried to verify where I can that there's no shorts or cold solder joints, but without the board I'm sure theres parts I missed. Any help would be very appreciated!
Supply MCU from backboard with 3.3v or with an external power source. Do not use ( disconnect ) power supply pin from PICKIT to the front board (do not power front board from PICkit)

Re: Really universal soldering controller

Reply #5459
Quote
Supply MCU from backboard with 3.3v or with an external power source. Do not use ( disconnect ) power supply pin from PICKIT to the front board (do not power front board from PICkit)

Alrighty, so here's the steps I follow:
Quote
1. "You can NOT program the PIC via the PicKit2/3 standalone programming software. You have to put the programmer into MPLab mode in the standalone software then program it via MPLab."
I have not been able to use Pickit in standalone mode, use it in MPLab mode.
2. Connect Pickit to UniS board, 'arrow' pin on Pickit should connect to programming pin UniS board - it is the only one with SQUARE pad, others are round pads. 5 pins on UniS board used out 6 pins on Pickit, pin 6 is not used.
3. Hold the button on Pickit, while holding connect it to USB
4. Start MPLab IPE (not IDE app within the package, which is for development purposes)
5. After Pickit starts flashing release the button
6. In MPlab choose the MCU to program - PIC32... (take it from BOM). Power up UniS board from the back board.
7. Hit connect in MPLab. You see that MPlab uploads firmware to Pickit itself, prepares firmware to PIC32 etc.
8. Now choose HEX file  - front/US_firmware.../dist/PIC32...standalone/production/US_Firmware.X.production.hex
9. Hit 'Program'. At the end you should see something like 'programming successful' and your UniS should come to live ('NO INSTRUMENT' message, etc)
from salavat on February 16, 2019.

So the only difference is not connecting the power supply pin from the pickit and using only backboard power?