LaserWorld Scanners gets extremely hot.

[rfourt]

Are you sure that BOTH V+ and V- are getting to the scanner driver board as they should? Are you sending a DC offset into the scanner some how? It sound like you're driving it all the way, one way and burning it up!


James.

Yea im pritty sure. but i will reconnect all cables today and see..

DC offset? dont really know what that means.

But i will also check the pins that goes from the driveer board to the scanner and see if it differs from the other driver board. But if i think about it yea that could be a problem also but the particular driver board get smoking hot also.

i will do some testing today.. will post pics and stuff here in a couple of hours.. just gonna get my daily dose of "Battlefield2" first. :P

[heroic]

Yea im pritty sure. but i will reconnect all cables today and see..

DC offset? dont really know what that means.

The waveform being fed to the galvo should usually be an AC signal centred around zero; if it's not, the difference is called a DC offset.


Measuring this without an oscilloscope isn't very easy.

[rfourt]

i have simply came to the conclusion that the Y scanner is somehow broken/fried etc.

if i have everything pluged in

Driverboard X
Scanner X

Driverboard Y
With unplugged scanner Y

Everything works fine. no heat or nothing.


As soon as i plug in the Y scanner the Y DriverBoard gets really hot and the scanner also.


I have tested to connect "DriverBoard Y" to "Scanner X" and it works without any heating.

so without any further measurements with power meter etc. i found that the scanner Y is cousing the heating.

just hope LaserWorld will replace it, bought from them on ebay so mayby not.

Strange that it is broken directly from them but mayby something hapend in the transport or to litle testing.. i dont know.



thnx again for the help.

/Rickard

[James Lehman]

Measure the DC resistance of both of your scanners. You may have a bunch of shorted turns of wire on the bad one. It would measure closer to zero ohms and draw a lot more current.

James.

[buffo]

Rather late getting into this thread... Looks like you've already found your problem though. I agree, it looks like your Y galvo is shorted. They should *never* get that hot. Hopefully LaserWorld will replace it.

As for the ILDA ground (pin 25), that should be connected to the ground on the DC output side of the scanner amp power supply. It does *not* need to be connected to the signal input ground terminal on the scanner amps. (And in fact, if you connect it there you can cause noise to show up in your scanned image.)

Adam

[Things]

I had a very similar prob with my scanpro 20's X galvo. It heated up VERY fast, aswell as its driver board. What I had found, is the large end bit with the plug, and twisted from the rest of the body, so the shaft was jammed and it was heating up. I just simply twisted it back. It still seems slightly out of whack, but I had a concert I needed it at the next day. It seems to have got very noisy. Nothing but abit of tweaking cant fix

[rfourt]

Rather late getting into this thread... Looks like you've already found your problem though. I agree, it looks like your Y galvo is shorted. They should *never* get that hot. Hopefully LaserWorld will replace it.

As for the ILDA ground (pin 25), that should be connected to the ground on the DC output side of the scanner amp power supply. It does *not* need to be connected to the signal input ground terminal on the scanner amps. (And in fact, if you connect it there you can cause noise to show up in your scanned image.)

Adam

The "DC-ground" would be the ground farest to the left on my picture? or one of the 2 grounds betwen V+ and V-?

thankx,

/R

[buffo]

The "DC-ground" would be the ground farest to the left on my picture?

No, the one on the far left is the ground for the incoming AC power.

or one of the 2 grounds betwen V+ and V-?

Yes. Those two ground terminals are common to each other. That's your DC ground. Connect pin 25 from the ILDA connector to one of those terminals. (It doesn't matter which one, but for clarity it might be best to use the one that is between V+ and V-.)

Adam

[rfourt]

ok thank you.

called LaserWorld today. and they told me to email. so ill keep it posted here whenever i hear something from them.

Thnx again.

/Rickard

[buffo]

Cool. Hopefully LaserWorld will send you a new galvo and amp. But yeah, let us know how it turns out... Good luck!

Adam