Old Regular UHU (for 60V to 80V and less)

[contactirfu]

THis thread is dedicated to all the posts which use the original PCB design for the UHU, this is also meant for people who are using PCB from manjeet and others following the old format PCB.

[mikec8100]

I have just finished testing my new power supply for 3 standard UHU's running ametek servos (38v, 12amp max) The power supply uses 2 Laminated core transformers (350va?) in paralall, 2 large caps and 10a fuses between each UHU. It produces 50v no load, and when I draw 8 amps from it it drops to 47v My question is can i use this power supply with my ameteks (38v) or will that cause damage to the servos?

Thanks for your help on this one.

Regards.

[contactirfu]

I would not!

[LZ1TWB]

The power supply for your 38V motors should be around 44V (+15%). 50V is not so far above so I think they will run just fine. Surely they will heat a little more but this should be examined during testing.

As a reference I have my 56V-rated motors running with a 66V PS. Of course if you are not going to use the full speed potential of your motors you could definetely go with a lower voltage PS - say 35-40V.

Todor

[mikec8100]

Thanks, thats what i thought. I definately will need the full speed potential of my motors as they are only rated at 900rpm. On my Y axis of my Mill Drill i m converting i am using a 2.5mm pitch ball screw. I will need to direct drive this axis to come even close to fast enough rapids. (37mm/s)

[contactirfu]

Hi Mike,

do let us know the results!

RGDs
Irfan

[simmo993]

Hello,


For almost 2 years I'm trying to start building a new CNC machine.
When searching the internet I came accross the UHU controller.
Last year I ordered the Controller and Crytals with Uli Huber.
And with the last PCB action on the german Message board Peters' CNC ecke
I ordered 6 PCB's (the old layout 20/10/2005).
Now I want to order the parts for putting the UHU board's together.
I found so many threads on the net CNCzone and CNC ecke about the controller, that it's almost impossible for a newbie to filter all that info.
Now is my question. Does someone have single and clear parts list for ordering all the elctronic parts. I know that one can find such a list on
http://people.freenet.de/Mode1/UHU_P...uecklisten.xls.
But for me there's still too much not clear. For instance
I want to use the opto3 option: HCPL2231(stated by Uli as the best option).
Then in DIY servo controller thread, tomkroscavage (05-23-2006, 08:04 PM)wrote when using this optocoupler: "If you are using the HCPL-2231 just do not insert R18 and R25 as this opto comes with internal schmitt-trigger and
push-pull-drivers and is already TTL compatible."

So is there someone who can give me a non-ambiguous list for building a UHU controller using IRFP260 (150V DC and 30A) and HCPL2231

Greetings Sam

[vroemm]

Originally Posted by simmo993 when using this optocoupler: "If you are using the HCPL-2231 just do not insert R18 and R25 as this opto comes with internal schmitt-trigger and push-pull-drivers and is already TTL compatible."

If he is right then it works like this:

Many opto couplers work just like a hand switch.
A switch does not give any voltage or current.

Imagine a hand operated switch between pin 7 and pin 5 of IC11 opto3.

If the switch is open, then there is no current from +5 volt through R18, through the switch to GND.
As a result the voltage on pin 7 will be +5 volt.

If the switch is closed, then there flows a current from +5 volt through R18, through the switch to GND.
As a result the voltage on pin 7 will be 0 volt.

The voltage on pin 7 comes from the +5 volt via R18.
Not from pin 7 itself.
R18 is in this case called a 'pull up' resistor.

This is how many opto couplers work.

With the HCPL2231 opto coupler it works different.
It does not work like a switch.

The pin 7 of the HCPL223 works as a small voltage supply.

If the HCPL2231 gets a ON signal, it will create its own +5 volt signal on pin 7.
Then there is no need for a R18 pull up resistor to create a +5 volt.
If the HCPL2231 gets a OFF signal, it will create a 0 volt signal on pin 7.

With a HCPL2231 you do not need the R18 pull up resistor.
And R25 is also not needed, it does the same for the other channel of the HCPL2231.

That is, if he is right.
I have looked at the HCPL2231 datasheet, with my limited knowledge i can not see if the pin 7 indeed works like a small voltage supply.
Hopefully someone with more knowledge can tell us :-)

On the other hand, leaving the R18 and R25 in is no problem with the HCPL2231.
It probably works fine.
Can someone "officially" confirm this ?

http://www.datasheetcatalog.com/data...CPL-2231.shtml

Vroemm.

[LeissKG]

Originally Posted by vroemm That is, if he is right. I have looked at the HCPL2231 datasheet, with my limited knowledge i can not see if the pin 7 indeed works like a small voltage supply. Hopefully someone with more knowledge can tell us :-) On the other hand, leaving the R18 and R25 in is no problem with the HCPL2231. It probably works fine. Can someone "officially" confirm this ? http://www.datasheetcatalog.com/data...CPL-2231.shtml Vroemm.

Yes, the HCPL2231 does not need a pullup on the output ( stated in bold on the first page of the datasheet under features ). It can directly drive 4 TTL loads.
It should work with the pullups in the circuit if the resistor value is not to low. The only difference should be slightly slower slopes of the signal.

Klaus Leiss

[vroemm]

Originally Posted by LeissKG Yes, the HCPL2231 does not need a pullup on the output

Thanks for the info.
I have added it to the UHU wiki.
http://gsst.wikispaces.com/UHUget

Vroemm

[kreutz]

Originally Posted by LeissKG Yes, the HCPL2231 does not need a pullup on the output ( stated in bold on the first page of the datasheet under features ). It can directly drive 4 TTL loads. It should work with the pullups in the circuit if the resistor value is not to low. The only difference should be slightly slower slopes of the signal. Klaus Leiss

True, but your UHU board will require both pull-up resistors if you are using a 74HC14 chip instead of the 74HCT14 or a plain 7414N (or 74LS14) chip.

Kreutz.

[vroemm]

Originally Posted by kreutz True, but your UHU board will require both pull-up resistors if you are using a 74HC14 chip instead of the 74HCT14 or a plain 7414N (or 74LS14) chip.

Oeps :-)
The parts list says the IC10 is a 74HC14.
Best to go from there.
I have removed the comment, about removing R18 and R25, from the uhu wiki.
http://gsst.wikispaces.com/UHUget

Thanks Kreutz !

Vroemm.