DIY Servo controller

[LZ1TWB]

+12V are used by the mosfet drivers IR2184, not only by the 7805 for the chips, that's why. I was wondering another thing - why there should be 7812 for each UHU, since it could do with one and a power transistor, but it may be better that way, as the axes are somehow sepparated from each other.
I don't know if it is a problem to drive multiple UHU's with just one regulated 12V and not for each one. Someone to comment on this?

Greetings,
Todor

[koslaz]

Thanks for the reply LZ1TWB!
I guess I better start looking for a
regulated PS!

[avr32]

Originally Posted by koslaz OK guys, here is the question: Is it posible to feed the controler with 12v but not regulated? .

Yes it is!

[koslaz]

Hi avr32!
What do you mean?
Did you actually managed to run the controller without
an regulated PS?
I would like to hear more details.

Koslaz.

[FPV_GTp]

Originally Posted by LZ1TWB Hello guys, what will you say about this motor and is it suitable for the UHU drive. It is an industrial servo motor, bulgarian license of Fanuc 0 Motor specs are 2.7Nm 2000rpm Vmax=56V Inom=12A, max100A I /no load/ = 0.7A 12kg + mounted encoder 2000imp/r under back cap I has 4 brushes and large collector /around 70mm dia/ with 99 leads And here is a picture:

Hi

LZ1TWB , that certainly is a big servo motor for hobby application

But my thinking is the same as yours , small servo motors are not cheap and there is a vast amount of industrial servo motor floating around on ebay.

The torque and speed these industrial servo motor work with is ideal for a hobby application if one could find a good HOBBY PRICED SERVO MOTOR CONTROLLER rather than having to pay BIG DOLLARS for a commercial type servo controller.

Yes there are guys out there that need a larger amperage servo controller for there CNCHOBBY shop.

What is the biggest current a hobby servo controller can hold at peak load ?


cheers

[contactirfu]

I have a PS of 110v DC and 20 Amps, i am planning to have a 1 k 10watt resistor for shunt- to short the caps when power down- is it ok?

[Torchhead]

Are you talking about something that switches in when you shutdown the power (like using a SPDT 30A relay) to bleed off the DC charge or something that stays hooked up all the time? If it's just a bleeder resistor (hooked up all the time) the 1 K will dissipate about 12 W all the time. Even at 10W the resistor will get VERY hot. At 12 it will start to smoke over time. Raise the value to 2K and the dissipation drops to about 6W. It will take longer to discharge the caps (depending on their value)

If you can use a relay that has lower value of resistor and only switches in when you shut down then you can get more aggressive with your bleeder. Since it is only on for a few seconds the dissipation is only over the discharge time. Total power is an intergal function of the discharge time. One one of our products (shameless plug) I designed a constant current discharge (set @ 5 Amps) that cuts in during shutdown and discharges a 40,000 mfd cap in about 3 - 4 seconds. It also functions as a dynamic load to clamp back EMF. Since the circuit also incorporates an Overvoltage Protection and AC side shutdown (turns off the input power to the power supply) it provides a complete AC-DC control solution.

Tom Caudle
www.CandCNC.com

[smarbaga]

uhu controller boot test complete.
all these boards power up and display the boot message.
- next i will hook a motor/encoder/motor power supply/bob to
these controllers and put them through there tests,

- i have made several of these boards in the past with 100%
success and i see no reason why these should be any different.

I will be selling these boards assembled, tested and working for:
$ 85.00 each. - first come , first serve bassis
- shipping of your choice, from 46947 indiana USA.
- money order or certifyed check.
IF anyone is interested contact me at:
smarbaga@yahoo.ca
574-516-6160, 574-516-6262
or pm me here.
thanks , reguards , garry

[contactirfu]

Originally Posted by Torchhead Are you talking about something that switches in when you shutdown the power (like using a SPDT 30A relay) to bleed off the DC charge or something that stays hooked up all the time? If it's just a bleeder resistor (hooked up all the time) the 1 K will dissipate about 12 W all the time. Even at 10W the resistor will get VERY hot. At 12 it will start to smoke over time. Raise the value to 2K and the dissipation drops to about 6W. It will take longer to discharge the caps (depending on their value) If you can use a relay that has lower value of resistor and only switches in when you shut down then you can get more aggressive with your bleeder. Since it is only on for a few seconds the dissipation is only over the discharge time. Total power is an intergal function of the discharge time. One one of our products (shameless plug) I designed a constant current discharge (set @ 5 Amps) that cuts in during shutdown and discharges a 40,000 mfd cap in about 3 - 4 seconds. It also functions as a dynamic load to clamp back EMF. Since the circuit also incorporates an Overvoltage Protection and AC side shutdown (turns off the input power to the power supply) it provides a complete AC-DC control solution. Tom Caudle www.CandCNC.com

Thanks Tom,

thats what it is- a bleeder resistor : S**T why dint I see your web site before purchasing Mach 3, your stuff would have had been great for my router.

well i will go in for the 2k 10W bleeder right now. Sort of out of hard cash right now.............

Thanks for the input........

[smarbaga]

the uhu controllers are assembled and all test good. :-)
- if you are interested in some , let me know ( see thread # 608 )
see pic below , thanks

[miljnor]

Hey Smarbaga what mosfet or better yet what Voltage/amperage did you build these for?

This thread has several options dosn't it?

thanks

[smarbaga]

miljnor: hello
- i have run a 7 amp - 42 volt motor off of them.
with little mosfet heat, i guess due to current pulsing/pwm.
- i have sold these boards with 200 volt fets.
- i don't know what amps these people were using,
but i have had no complaints.
- i would beef up the traces with jumper wire if i were going to use big amps.
- these boards at present have 100v irf540 fets , but this can easily be changed as the fet footprint is also layed out for the lager to218's.
- you could also go off board with modules if one desired.