Help!!

[edison]

I bought a computerpowersupply for powering my laser projector and i wanted to know if anyone knows how to get the powersupply working stand alone. There is one connector that has 20 pins and if you connect two pins together from this connector the fan starts to turn and the 5 v is working but not the 12v. I think computersupplies have a standard for the connector but what are they? but maybe someone can help me.

Is there a computerwizzard her at PL?

[mixedgas]

which type of power supply?

usually you need a resistive load on the 5 volts to enable the 12 and a pair of wires shorted.

Steve

[keeperx]

if its atx, short circuit the 14th (Green) and 15th (Black) pins using a wire.

[heroic]

if its atx, short circuit the 14th (Green) and 15th (Black) pins using a wire.

You'll also need to put about a 2.5 ohm 2 watt resistor between the 5v rail and ground unless you are drawing a lot of 5v power for your laser gear; ATX power supplies generally require you to draw around an amp or so from 5v before their regulation works correctly.

[edison]

Thanks guys

I bought a Zalman 600HP. I connected pin 14 (ps on ) to ground and pin 9 5v standby to 5v but only the blue lights in the powersupply turn on. The fan doesn,t turn. I have a laserwave 500mw that needs 5v 6amps but i dont,t want to use it as a load before i,m sure that the powersupply works fine. Also i measured 5 v but the 12v( yellow wire) nothing. Maybe its good to upload a layout of the ATX connector and how to connect the pins to get a computerpowersupply going for other PL members because its ideal for powering you projector. Maybe a layout on the FTP server?

[keeperx]

[heroic]

Thanks guys

I bought a Zalman 600HP. I connected pin 14 (ps on ) to ground and pin 9 5v standby to 5v

Don't connect 5VSB to 5V. That is not a smart thing to do as you'll risk forcing the (very limited) 5VSB regulator to drive the whole load. Just put a resistor (or a sufficiently heavy load) on the 5v rail and you'll be fine. Power supplies have crowbar protection against overvoltage on the 5v rail, so it won't break your laser, but when the laser is idling it won't draw enough current from the 5v rail to keep the PSU's switcher happy; you need a dummy load or at least a couple of 5v fans to apply enough load to the thing. A good dummy load is a 2.5 ohm 2 watt resistor.

-J.,
expert abuser of PC components

[edison]

thanks KeeperX thats a great help! Could anyone fill in the connections between the pins to get powersupply going? I think this is a great help for Pl members that are building a projector. why use seperate powersupplies that take a lot of room if you can do it with one Steve, so if i understand it correctly you have to put a load on the 5v to measure anything on the 12 v?

[SideFX]

Google is your friend:

http://www.helpwithpcs.com/courses/p...nc-pinouts.htm

Could anyone fill in the connections between the pins to get powersupply going? I think this is a great help for Pl members that are building a projector. why use seperate powersupplies that take a lot of room if you can do it with one Steve, so if i understand it correctly you have to put a load on the 5v to measure anything on the 12 v?

I mainly use PC-power supplies for my projects.. both laser- and non-laser related.
The only thing you need to do is to permanently connect the PS_ON (Green wire) to GND (black).. that's all. No load needed on 5V if you only use 12V and vice versa.

[heroic]

I mainly use PC-power supplies for my projects.. both laser- and non-laser related.
The only thing you need to do is to permanently connect the PS_ON (Green wire) to GND (black).. that's all. No load needed on 5V if you only use 12V and vice versa.

Sadly, the last sentence here is not true. Many PC power supplies are unstable, poorly regulated, or just plain don't start without a load on the 5v rail. See Horowitz & Hill for the reasons why.