[mikec8100]

Hi there, i am in the process of building my first uhu servo controller. I plan to get one working, and then build another 2 to run my small mill.

i have a few questions on components, as this is m first project of this complexity. i did make my own pcb bords using glossy photo paper, and a laser jet, with excilent resaults.

just need to know, can i use dioeds labeld in4007 for all of the diodes on the bord? or do i need to use the exact dioeds specified? i have solderd them in, but am looking at the diagram having read the discription of components on page 34 of this thred, i am unshure if they will work.

also what is the component located just beneath the mosfet's on the right hand side of the bord? it is labeld 100n RM15, wich leads me to beleive it is a capasotor of some sort?

thanks in advance for any help.
Mike Christiansen

[ejkoeze]

You need the exact diodes as specified.
The 100n RM15 is a cap (100nF) leg 15 apart.

There have been no changes to processor or board layout since october 2005.
There is however movement in that the guy that originally layd out this board is now working on a 19" version. He has run into problems with his layout so nothing workable yet.

Erik Jan

[mikec8100]

thanks for that Erik,

how can i tell if i need the diodes for the mosfets if i am using the IRF540N, it has a diode symbole on the caseing?

thanks

[smarbaga]

these transorbs give the fets extra protection from back emf ( motor kick back).
if you want the extra protection put them in. back emf will depend on your motors and if your system will ever free wheel.( ie:turning the motors by hand with power to the controller board).

[mikec8100]

hi there, just a nother question, can i use pollyester or mylar caps around the optoisolator? close to getting this thing moving, thanks to everyone for your help!

[smarbaga]

hello
if you are talking about the 0.1 uF bypass caps, try to use ceramic.if you don't have them, use whatever you have.

[mikec8100]

I have now recived my chips from uli (thanks Uli) and am trying to get the controler to talk to the pc program. so far i have had no sucess, when i power up the controler i get the 5v led come on, but thats it, is that correct? i am thinking it may be the capacitiors next to the max 232 chip? they are eletrolitic 16v, 10uf. what procedure should i use to chek the bord. thanks for all of your support.
Mike Christiansen.
(New Zealand)

[smarbaga]

hello
i have some uHu servo controllers for sale.
prices in us. dollars, per system. ( each )
----------------------------------------------

bare boards ------------------------- $ 11.00

kits, all parts, --- 100 volt system -$ 80.00
--- 200 volt ststem -$ 90.00

assembled & tested - 100 volt system -$ 100.00
- 200 volt system -$ 110.00

shipping 1-3 bds.- bare boards - usa -$ 5.00
via ups - world -$ 8.00

1-3 kits or assembled - usa -$ 15.00
- world -$ 22.00
----------------------------------------------
contact - pm me here.
- e_mail, [email protected]

payment - check
- moneyorder
- paypal
----------------------------------------------
see pics below, e_mail with any questions.
thanks, garry

[vroemm]

i have some uHu servo controllers for sale.

Hi smarbaga,

In your pictures the FET's are allready soldered in place.
But the cooling element is not yet in place.
Putting the cooling element as last in place gives mechanical stress.
Which can over long time lead to breaking of the soldering.

Better to first screw the FET's and the cooling element and the PCB together.
As last solder the FET's to the PCB.

Just a tip :-)

[LZ1TWB]

Hello mikec8100,
When boards are assembled and wired correct everything works perfect. When you turn the power on you should have the two left green diodes lighted up.
My suggestions are: check your serial cabel to the computer - it shoud be 1:1 pin-to-pin. There are some cables with the send/receive pair twisted. You should use COM1 port. It's better to have two computers on your desktop - one for the servo tuning and the other to control your drive - I use Mach 3 which is an excellent program.

[mikec8100]

I have tested the cable with multimeter, and pin 1 - 1 pin 2 - 2 and so on. if i plug the controler into the pc without power suppled it lights up the i-lim led, untill i start the software, then is shuts of. this only happens when no power is supplyed to the controler. when i do supply power, the i-lim led suts off regardless of the program, and the 5v led lights up.

thanks for all of your help

[LZ1TWB]

Current limiter LED cannot light without power connected to the board. Or maybe you mean motor power? Anyway it should not light, it does only when the motor accelerates and takes more current for that. You should have +5V and Ready LEDs on. You may have some wrong connections on your board - also check diodes polarity. On my first tests I had some similar problem and it ended with a cross link between some close traces on the board - some of them are tiny enough not to see the problem without carefull inspection. Good luck with the servo!

[mikec8100]

yea, the current lim light is on without the 12v lodgic power on??? if i follow the trace from it, one goes into the max 232 & the other goes through a 1k2 resistor and into the ic next to the uhu ic. how can i check the function of the 4013 ic as i have checked the voltages againsed the chart listed in post 407 and they are all the same except the 4013 chip. i have checked all of the traces, and had fixed the faults before i powered up the controler. do the ir2184 chips need to be instaled at this stage? i have not found a supplyer for these yet, so im trying to just get a conection to the software. i still have not had the h-on led light up yet? is this the status of the uhu ic? do xtals have a polarity? thanks for the help, it is invaluable.

[liftfan]

I have been going over this forum for a long time and have downloaded a number of different items . particularly interested inthe full layout for Chip"s EMO servo controler including the output drives as shown in his pictures.
However, because he has used an engineering program not available though windows XP I cannot open his downloads . could someone please post it in language and pictures for normal download. I like the strip board design because I like building my own product and find this very usable .

Thanks for any help ,

Liftfan

[LZ1TWB]

There may be differences in the voltages of the 4013 chip if you haven't put the 2184 as they are connected. I cannot realize how can the curr lim led light if no power to the board is given, just the serial connection. Power to the led is taken between negative 12V from 232 and the output of the Op Amp which is a comparator between the 10K Pot and the current sensing resistors voltage.
As I know the only necessary things to accomplish a connection with the computer are the UHU chip, Xtal, xtal caps, 232 with its caps and power.
Check if your serial port is enabled in BIOS and ready in device manager.
Bye

[mikec8100]

sucess!, well sort of. i had not conected the jumper under the max 232, therefore the xtal or uhu was not getting ground. so now when i power up the bord i get the 5v light on then followed by the h-on light. still get the current limit light on when no power is on the bord, just the serial conection. could the 5k trimpot being around backwards cause this? i am unshure of the polarity of the trimpot. or i wonder if this could be caused by a fault in the max 232? still have no pc conection, i have been into the bios and enabled both com ports 1 & 2 and i have gone into the device manager and configered the com ports to run at 38400 baud, 8 data bits, no parity, 1 stop bit and no flow control. i have tryed both the windows xp and the dos software on two diffrent pc's.

have 10uf electrolitic caps worked for people with the max 232 in the past? or what caps should i try?

this makes buying premade and tested units look realy cheep!

Thanks to everyone for your help

Mike Christiansen

[kreutz]

Measure continuity from the Serial cable connector that goes to the PC to the pins on the MAX232 chip. If OK, then Get a null modem adapter and try the communication between the board and the PC again. IF it still does not work, you will need a scope to continue troubleshooting.

Did you replace the 9 pin connector with the opposite gender than the one specified? If you did, you will have to unsolder it and solder it back on the copper side of the board.

[mikec8100]

i think this may be the problem. i just cannot seem to work out wich pins go to where on the max 232? i have a male 9 pin conector on the top of the pcb. i beleave this is supost to be a female, so i have gone out and braught 2 female sockets and linked the pins togeather as i beleave i should. thanks for all of your help

Mike Christiansen

[smarbaga]

hello vroemm
i installed the heat sink, bolted down the transistors, then soldered them in place.
i then removed the heat sink for better vueing only
i am aware of the stress you are talking about
thanks for the tip.
it is very important and i hope it helps others in the future.

[smarbaga]

hello mikec8100
perhaps the -12 volt line is getting loaded causing your i-led to light and causing your 232 chip to fail.
i would remove all the chips but the max232 and the atmel and get serial communications first ( the welcome screen).
then move on down the road.
check for the -10 to 12 volts at the max chip pin.