+/- 24volts for galvos

[mixedgas]

In fact, I dont know about the clones, but the Cambs have a jumper set to switch in 7815 and 7915s on the board, so you CAN use unregulated rails.

We also used to cross connect a relay pair across the rails, to buy us a little time till both rails came up evenly. A time delay relay will also do this function well.

Steve

[badger1666]

how's the SMPS300R' power supply sbk ?
is it worth getting one ? , how many amps per rail can it supply ?
is there enough head room on it to power a set of dt40's and run a dc dc converter for 2 amps at 5v for a couple of diodes

[blowfly]

Hi, a couple questions on wiring. Is this the right way to wire two 24v power supplies to get -24v/+24v to run a set of scanners? Since I need 5v for everything else in the projector, is this the best way to use a DC/DC Converter to convert from 24v to 5v?



Thanks for any feedback or ideas!
Mike

[Badpip]

Hi, a couple questions on wiring. Is this the right way to wire two 24v power supplies to get -24v/+24v to run a set of scanners? Since I need 5v for everything else in the projector, is this the best way to use a DC/DC Converter to convert from 24v to 5v?

+/-24V is correct. Paralleling the DC/DC converters may pose a problem. First of all they need to be isolated for your approach to work. Secondly, they have to support load-sharing.

Why not use a single 48 to 5V converter instead?

Something like this:

http://search.digikey.com/scripts/Dk...ds=811-2202-ND

/Thomas

[blowfly]

Why not use a single 48 to 5V converter instead?

Great idea! Should have thought of that. Thanks Thomas.

Mike

[sbk]

how's the SMPS300R' power supply sbk ?
is it worth getting one ? , how many amps per rail can it supply ?
is there enough head room on it to power a set of dt40's and run a dc dc converter for 2 amps at 5v for a couple of diodes

It's doing very well, worth every penny. It gives 180W nominal, 250W peak power so no worries I believe you can power your entire projector from it About current it should be 3.75 amp per channel at 180W.
Big output capacitors also which is great for peak current request from your scanners. And it features all the necessary protections such as overcurrent, overvoltage, overtemperature.

[badger1666]

i have some questions.
what size +- 24v supply would i need if i want +- 24v at 2amps
and want 5v at 6amps from a dc,dc converter running on it ?
also can you run the dc dc converter off one rail, or do you have to use the 48v type that run off the 24v+,24v- rails ?
can you also run more than one dc dc converter at a time ? ie one for 5v and one for 12v ??

hope some one can help with my dumb questions

[Badpip]

i have some questions.
what size +- 24v supply would i need if i want +- 24v at 2amps
and want 5v at 6amps from a dc,dc converter running on it ?
also can you run the dc dc converter off one rail, or do you have to use the 48v type that run off the 24v+,24v- rails ?
can you also run more than one dc dc converter at a time ? ie one for 5v and one for 12v ??

hope some one can help with my dumb questions

48V input DC/DC converters will be "nicer" to the power supply, as both rails will be loaded equally.

In principle, you can connect as many as you want, but the powersupply might not like the start current if you connect too many - delayed powerup would then be needed.

5V 6A = 30W. If we say the efficiency is 80% input power will be 30/0.8 = 37.5W.
37.5W / 48V = 0.78A on top of your +-2A. Round up, and a +-24V/3A supply will do.

If you use those audio amplifier psu's please note that they are designed for a crest factor of 1:3, so they will only supply one third of the rated power continuous. The datasheet for the SMPS300R say it will do 100W. To get more than this, a heatsink must be used.

/Thomas

[badger1666]

would a smps500r be a better choice ?
would give enough extra power to run a tec off a dc dc converter as well
or should i stick with the 300r model ?

thanks

[Badpip]

Board size is the same, and the price difference is small... I would get the bigger one.

That also leaves room for upgrades

/Thomas