Suggestions on suitable PSU and query on current draw of CB6580 scanner amps

[taggalucci]

I've got two very heavy and large toroidal transformers I bought second hand with my scanner set-up a little while ago. These are hooked in series to give me the +24v and -24v required for the Cambridge Technology CB6580 scanner amps.

I know that a suitable switch mode PSU should be OK, but I need to know the appropriate specs to find one here in Australia (240v AC). I have been told that these amps draw a minimum of 2A per leg but that I should allow at least 8A per leg for headroom.

I've not been able to find the technical specifications or manual for these amps. Does anyone know where I could find these or have any suggestions on a suitable PSU?

[mixedgas]

http://www.skywise711.com/lasers/scanner/scanner.html

Skywise is kind enough to host this for me..

Steve

[taggalucci]

Here's an accumulation of what I've found so far:

http://www.skywise711.com/lasers/scanner/scanner.html

Skywise is kind enough to host this for me..

Steve

Thanks Steve! This has been very helpful

There's also now an updated version of the manual on the FTP server. Here's a relevant excerpt:

Input Voltage Requirements:
+/- 15VDC to +/- 28VDC @ 4A Max RMS

Input Power Requirements:
10 watts minimum
200 watts max rms (depends on type of scanner)


So I assume from the above, that the combined total required for each + & - input supplying both boards would be 8A / 200W.

Alternately, you could go shopping for a pair of single-ended power supplies with floating outputs and place them in series to make your own dual-ended power supply. Just make sure you get the voltage and current ratings right.

I've not been able to source a dual-ended/bipolar SMPS conforming to these specs that would be sufficient to power both boards, so I think I'm going to need to do this.

If you do this, you must first be absolutely certain that the DC outputs are floating with respect to the AC ground. (That is, the DC outputs are completely isolated.) If that's that case, they you connect the - terminal from one PSU to the + terminal of the other, and this middle point becomes your new ground point that gets connected to ILDA pin 25. (Remember, with an isolated circuit, ground is wherever you decide to make it.) Now you'll have +24V from one PSU, and -24V from the other, with the ground in the middle where the two connect.

So I've found a local supplier and confirmed that the PSU's DC outputs are floating in respect to AC ground. This is the model I've found, and at a reasonable price compared to others.

http://www.computronics.com.au/meanwell/sp-200/

So my current thinking is that I'll need two of these linked in serial to provide up to 8.4A / 201.6W for each + & - input (supplying both boards).

Is anyone able to confirm I'm correct in my assumptions?

[dave]

Those supplies would work fine, however you might need to mod your scan amps to prevent the negative rail locking up if the positive rail rises first ( or is it the other way around, cant remember ) Not really a big problem, that cant be fixed with a few diodes..