Questions for my first build

[mrchew]

hi all,

first let me say that this is a wonderful project and a great group of people here. It's amazing what you guys have accomplished!

I'm doing my first build and wanted to ask for help before i blow something up. I bought a kit from Paul (Tentalman?) and i have it assembled... i think.

The problem is this: there is so much information required and it's not organized into one spot. (I'm going to try to help with this as I go, maybe on the WIKI)

I used the latest parts list posted here:
Revised Bills of Material for HP UHU Drives

There are a few internal inconsistencies in the document. The main page doesn't agree with the other parts lists for a few values. I've been trying to contact paul on the issue, but no luck.

Now i've stumbled into a page on the wiki that says to replace these components:
C28 replaced by 4.7 uF/25 V Tantalum capacitor
R39= 2.2K 1/4 Watt (original value)
R38= 4.7K 1/4 Watt *
R21= 6.8K 1% 1/4 Watt (original value)
R54= jumper wire.
Add 1N4148 diode between jumper wire and GND (cathode to GND)
Replace C29 (100pf) by 470 pf ceramic capacitor.

To Paul's credit most of this was already done in the kit. I do have three questions so far:

1. what pin location are the cathode and anode on the board for the LED's? (rev.10.b) I'm used to square pads, but there isn't any indication on the board. It would be helpful if the answer was given in relation to either the encoder input or the 15V input.

2. Is there a pin out diagram for the DB15 connector for the encoder? I want to make my own cables... (Nevermind HO gave a great answer here:
http://www.cnczone.com/forums/showpo...2&postcount=17
)

3. Where is a good place to pick up the ground for the diode mentioned above for R54? should i start a "star point" off board?


This is what i have so far:

I'm using 190V brushed dc motors rated at around 1 amp continuous.

I'm going to power these from rectified 120VAC power giving me ~160VDC. I have a 130VAC MOV in place on the inputs of the bridge rectifier to protect against transients. My power supply has 6x 1000uf 450v capacitors and one HUGE transformer being used as an inductor in a "pi" filter or LC circuit (2000uf before inductor, 4000uf after). in addition to those i threw in 4 2uf poly film capacitors to help out. I have more capacitors, but i think that this setup should bring me down to less than 10% ripple.

for encoders i'm using 1024 cpr renco RM15's. i'm going to set up some 26LS31's on some perf board to send signals back to the board using either multistrand CAT6 wire or three lengths of twisted&shielded 18ga speaker&mic cable.

I think that i found a computer (a celeron! woohoo!) to run the setup for now, haven't tested it yet though.

[tenmetalman]

Matt,
First let me ask you to look at all the sites I emailed you. second your question about the correct led installation. the flat on the bottom of the LED designates the negative lead. all of the LED's are installed in the PCB with the negative pointed toward the 15 volt input.
the following is Kreutz"s post for installing the jumper & Diode.
" About the current limit circuit, it will re-check the resistor values tonight, and let you know of value changes (it was originally calculated for 13.5 Amps continuous)

CURRENT LIMIT CIRCUIT MODIFICATION (for early HP UHU Rev 1.0b boards ONLY)

Solder a jumper wire across R54 (33K) or replace the resistor by a jumper wire. Solder a 1N4148 Diode, Anode to R54 (jumper wire), cathode to ground. (Across the VR16 Potentiometer) Adjust VR16 potentiometer to get a voltage = 0.01 times the maximum continuous current (in Amps) at the Current Limit Test Point.

If your motor's maximum continuous current is higher than 11.3 Amps then cut R20 (1K) leads (un-populate R20), and adjust the voltage at the Current limit Test Point to 0.01 * Maximum continuous current (Absolute Maximum = 0.24V => 24 Amps). Also un-populate C28 (4.7 uF).

Power up test with no motor voltage: Measure approx 0.6 volts DC between the jumper wire (R54) and ground (across the 1N4148 diode). If there are more than 0.7Volts the 1N4148 diode is probably reversed."

Hope this answers your questions............... if not ask again & I'll try again

Tenmetalman

[rokag3]

hello Paul,

I am rewiring my 2nd uhu hp the first work fine.
I found out that the info was difficult to get
so I suggest 2 thread named
how to buy and build the hp uhu <11.3 A
how to buy and build the hp uhu >11.3 A
with the price and the address to buy it
the full part list
the little things to check before welding some card may have problems remember henrik
and pictures of different stages
link explaining the changes that as been done.
that will be great because right now it's a bit messy and many potential buyer get affraid to start sade because it's a very good driver.
also you should propose the kit for the dump current

[mrchew]

Thanks Paul for all of your help. The picture was especially reassuring as i could compare mine to the "perfect" one...

the picture did raise one question though. The white block in place on C37, is that really a capacitor? i used a 200volt cylindrical electrolytic in that spot... but i got both in the kit. which should I use?

I'm still not settled enough to turn it on yet, still checking everything over and trying to get the computer going. I'm wondering how well a 400mhz celeron is going to run mach3, an upgrade might be in order!

[tenmetalman]

Matt,
Your correct in having the round blue or black capacitor mounted where you see the white block mounted on my drive. my drives are so close to the adjacent heatsink of the next drive that I had to move my capacitor to the motor terminals. the white box is a 1uF 250Volt polyester capacitor can be soldered on the bottom side of the motor terminals (bottom side of the PCB) in such a way as not to interfere with the heatsink. have you done the recommended tests on your completed board that I sent you a reference to ?
Paul

[mrchew]

sorry for the delay, lots of family drama! my sisters husband left her and my 2 yo nephew, and then they got evicted from their house. If I thought moving myself was bad, moving my sister was much worse!

I got the modifications done to the board that were posted on the wiki.

I followed kreutz' procedure, checked for shorts and then connected it to encoder, 15v and computer (USB & serial). CL light came on along with PWR. (boy was i excited at this point!)...

I started to see a little smoke and heard some pops. U5 was really hot and I think C13 might've smoked. I found the reason for this, my dif. driver board was shorted up against the motor. I fixed this and turned it back on, but I don't know if i need to replace some components. U5 still runs a little warm.

Then I went to check for 5v @ pin 10 on U4 (the controller). nada!

i'm stumped!

Just to make sure i'm checking the right place, pin 10 is the one on the lower left corner if the "notch" is facing straight up.

I thought that maybe the 5v was supposed to come from the computer, but i checked the pins on the USB and found 5v. Thought that maybe i had a cold solder joint somewhere, checked them all, resoldered a few, but still nothing!

I've attached a few pictures of the board. The power supply that I'm using is from audio equipment, puts out a solid 12VDC, and i connected an extra 47000uF capacitor to kill any ripple.

I really don't know where to start looking. I have a good meter and alot of patience, but i just don't know where to look!

[having trouble with camera, will post pics soon...]

[rokag3]

hello,
did you check the 7805 ? u1
also the usb port is only for the communications of the parameters with the pc it is connected only with u12 u13 optocouplers

what is your 12V for?

[rokag3]

u10 is the max 232
you are supposed to have the 5v of the pc on pin 16
top view
looking the hpuhu the usb connector pointed to you
the max232 is on your right
the notch is extreme right
the pin1 is on the left of the notch
the pin 8 is the last of the leftt side
then you have pin 9 at the same level than pin 8 but on the right side finally you have pin 16 on the right side of the notch on the extreme right of the board

[rokag3]

sorry you was talking for u4
pin 10 of u4 is ground
pin 20 is vcc 5v
this cicuit is oriented reverse with u10
the vcc is on the right side of the notch
the pin 10 is on the last pin on the left side


sorry i mixed up pin 10 and u10

[mrchew]

okay, first i want to show what i was going off of and what i was trying to check. to quote kruetz:

"First tests after successful assembly

Check all the connections, measure resistance across 15V terminals, Motor power supply terminals and motor terminals, no short circuit should be present.

Connect the encoder cable (with the pins 8 and 2 jumpered on the encoder side), RS232 cable to PC, USB cable to PC, and 15 Volt power supply. Connect the motor terminals to the right connector, but don't power on the motor power supply for this test. Do not insert the UHU chip on its socket yet.

Turn on the 15 V power supply and check the 5 volts between the 15V power supply GND terminal and pin 10 of the UHU chip socket. If OK, turn off the 15 V power supply and wait about 10 seconds for the voltage to drop to zero, then insert the UHu chip on the socket"

now if i understand correctly, i should be checking for 5vdc on pin 20? which is directly accross from pin 10? and this is all on the socket for the microcontroller?

sorry, just want to avoid any confusion!

[mrchew]

thank you for the quick reply, and thank you for your help. i don't know where i'd be without the great people here.

I should've said that first last time, sorry!

[rokag3]

I've attached a few pictures of the board. The power supply that I'm using is from audio equipment, puts out a solid 12VDC, and i connected an extra 47000uF capacitor to kill any ripple.

the 5v is made from the 15V
do not mixed pc ground and 15v ground!!!