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power supply +-24v.

juanma666

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Hi, friends.

I'm looking for a power supply for galvos (PT-30/PT-40). And I do not find any with the features this type of source. (+ 24v / common / -24V). Three cables (red / black / yellow) to power amplifiers galvo.
All I find are sources of 24v. But none with the possibility of + -24V using common as "neutral".


I tried searching even with the reference power supply manufacturer, but can not find any replacement.
Do you know where I could find a (reasonably priced) or could solve the problem with a similar source?


In case of not finding the correct power supply ... the diagram is correct, to connect two power supply 24v and get diferential of +/- 24V.?



Use two of these ...
Ground, can be common for AC 240V. and +/- 24v DC.?

http://es.aliexpress.com/item/AC-100...347045259.html

If correct this diagram ... with dual output power supply; more interesting for me because I use a source like this for galvos?

Can you help?

110-240V DC 12/24V Universal Regulated Switching Power Supply For LED Strip/CCTV | eBay

AC 240v.
24v DC.
5 Amp.
120 W.




Best Regards.
Juanma.
 



Benm

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Often you can use 2 units like that, but check first!

Most of them are isolated from the grounded metal frame around them, and it's no problem to hook them in series. Do make SURE that the negative output is not connected to the case (measure with multimeter) before powering things up, otherwise you will short one out.

You can find supplies with +24 and -24 in the same unit quite easily on ebay. Last time i got one that outputs 1 amp i think the price was $10-$15 shipped from china.

The 2x24v ones are hard to find, but it would be something like this Factory Direct CE RoHS D 30B 5V 24V Dual Output Power Switching Power Supply | eBay

You could ask a vendor of these things if they have one with -24 and +24.
 

juanma666

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Hello BenM.

Thank you for your help.

I could not find any power supply of +/- 24V. anywhere, or Ebay, or AliExpress ...
I contacted with Spacelas, but they do not send single units (one set of galvos).

I tried the model that I have (one double power supply) ... and the negative is not connected with the case, but the GROUND grounded network (240V AC.) A problem?

O earth AC disconnect and connect to galvos Ground?

I have this power supply is not connected with negative case (chassis).
This is the image of the power supply.






Best Regards.

Juanma.
 

juanma666

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If power supply good for galvos... scheme is correct?



Best Regards.

Juanma.
 

DashApple

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Doing that as above will short the PSU out .

That PSU is just a single +24V output
 

juanma666

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OK!
I imagined that is not dual structure is only double output connection.

I use two 24v PSU. separated.


Best Regards.
Juanma.
 
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OK!
I imagined that is not dual structure is only double output connection.

I use two 24v PSU. separated.


Best Regards.
Juanma.
Correct me if im wrong but you cant have 2 switching psu's in seiries unless they are on electrically isolated sources?
 

Apocalypse

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I did this a few years back and used 2 of these. I connected the V+ of one to the V- of the other and used that pin as ground. I then use the V- as the -24V and the V+ as the +24V.

Here's a diagram of it but with 12V instead of 24V. For the full range of your galvos, you need 24V.

 
Last edited:

Benm

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Correct me if im wrong but you cant have 2 switching psu's in seiries unless they are on electrically isolated sources?
The outputs are isolated from the inputs in these units, so you can.

You would be absolutely right if they connected ground to the negative output pin, but most of these switchmode PSU's don't do that. Ground is connected to the chassis, but the output voltage is isolated from that too.

Before proceeding you should verify this though, there are -some- supplies that do connect ground to output negative, although they are rare. If you cannot find a +/- 24v single unit, just get 24v ones and hook it up as drawn out, it will be fine for galvo's. It would be a good idea to adjust them to the exact same output voltage if they have an adjustment pot on them.
 

Benm

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Exactly as detailed in the very first post here.
 




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