How to controll servomotor controller with transistor/microcontroller

HI!
Now i have a servo controller (industrial) wich uses 24volts...
Now when i want to turn it on i get A pin to ground and works perfectly
Now i want to be able to control this servo motor controller with arduino...
...Done a lot of googleing... now im even more confused then before
I thought if i user NPN transistor i get the thing done...but like i sad googled and now im not shure any more...
So i want to:

arduino output ===> external 24V
signal LOW ===> singal HIGH (24V)
signal HIGH ===> signal LOW (ground of external 24vdc)

Any idea?

How about an opto-isolator like a 4N25; halfway down that link it shows a 24V load.

JimboZA:
How about an opto-isolator like a 4N25; halfway down that link it shows a 24V load.

This is not correct… becouse the output is 1=1 when input is HIGH output is HIGH…

here is what i want… and dont know what element to use and how to connect it $)
Please see attached file

test.jpg

If you take your output from the collector of the transistor (pin 5) and have a pullup to 24, I reckon that's exactly what you get:

  • When Arduino pin is low, led is off, transistor base is unexcited, transistor closed, 24V at collector
  • When Arduino pin is high, led is on, transistor base is excited, transistor closed, OV at collector.

JimboZA:
If you take your output from the collector of the transistor (pin 5) and have a pullup to 24, I reckon that’s exactly what you get:

  • When Arduino pin is low, led is off, transistor base is unexcited, transistor closed, 24V at collector
  • When Arduino pin is high, led is on, transistor base is excited, transistor closed, OV at collector.

Nononono…
Let me explain again :smiley:
Ok,
this is the schematics of the servo motor controller…
So as you can see DI-1 when not turned on is 24V,
If i want to turn it ON i have to close DI-1 pin to ground…
NOW
THIS IS WHAT i want to be able to do with microcontroler and transistor

HELP?

And i don't want to user a relay...

Use TD 62783 (or UDN2981 but it's obsolete) doing exactly what you want.

Pelle

Pelleplutt:
Use TD 62783 (or UDN2981 but it's obsolete) doing exactly what you want.

Pelle

Thanx!
So basicly i need a PNP transistor right?

Not PNP
With an NPN the current flows from Collector to Emitter (Emitter connected to GND)

Pelle

Ales:
So basicly i need a PNP transistor right?

Pelleplutt:
Not PNP
With an NPN the current flows from Collector to Emitter (Emitter connected to GND)

And what's a 4N25 if not an opto-isolating NPN transistor when used as a switch? The connection to the LED anode is essentially the transistor's base.

I think PNP is the right thig right?
like this darlington array MIC2981

datasheet: http://www.farnell.com/datasheets/188256.pdf

I'M SO SORRY VERY SORRY

I'm thinking absolutly wrong

You should use ULN 2003 or ULN 2803, they are NPN, connecting the input to GND

(as you say UDN 2981 are PNP, in this case it was completely wrong)

Sorry

Pelle

gonna try with uln2803 i have them....
gonna report back here... :smiley: