240v connection in AT psu

Slain · 25th July 2003, 12:02 AM

I have this PSU which ive pulled apart and now i have to re-attach the mains wiring to the pcb. The problem is i cant remember which way the wires went originally. There is 2 points, one goes directly to the full wave bridge rectifier and the other point goes though this component (i think its a thermister, black blob with NTC written on it) and on to the rectifier.

Can anyone help?

Rake · 25th July 2003, 12:04 AM

If you are trying to reassemble a PSU and don't even know where to join things / what to do, I would certainly not be plugging it into anything

Gnuthad · 25th July 2003, 12:19 AM

As above.

For the record, however, the active goes direct to the bridge, the neutral goes to the NTC thermister.

Slain · 25th July 2003, 6:10 PM

Quote:

Originally posted by Gnuthad
As above.

For the record, however, the active goes direct to the bridge, the neutral goes to the NTC thermister.

Cool, thanks

.

D F · 25th July 2003, 9:13 PM

In my experience there has always been some sort of L and N markings on the PCB

Gnuthad · 25th July 2003, 9:59 PM

Often, yes but not always. If there is a NTC thermistor on the board though, the neutral will always go to the thermistor. as the thermistor is used to slow down the cold-start inrush current when you plug in the PSU.

star882 · 25th July 2003, 11:11 PM

Quote:

Originally posted by Slain
There is 2 points, one goes directly to the full wave bridge rectifier and the other point goes though this component (i think its a thermister, black blob with NTC written on it) and on to the rectifier.

It's most likely the fuse, so that line is the hot wire.

Gnuthad · 26th July 2003, 2:36 PM

Please read replies to the thread before jumping in with your own incorrect claims. The thread has only a handful of replies, there is no chance you could have missed that it has already been established that the NTC thermistor is the component in question, not the fuse.

A NTC thermistor has an expoxy coating exactly as described, the fuse has a metal cap on each end of a glass cylinder.

With uninformed and obviously incorrect replies such as yours it is little wonder that so many people do the wrong thing when dealing with 240V. Please read the sticky at the top of this specific forum.

larrymoencurly · 26th July 2003, 6:09 PM

A NTC thermistor has an expoxy coating

I haven't seen that many thermistors, but the small ones were epoxy coated (shiney) while the larger ones, such as those used for on the AC line, had only a ceramic coating (dull).

This ATX PSU schematic could help.

25th July 2003, 12:02 AM	#1
Slain (Banned or Deleted) Join Date: Jun 2001 Location: Perth Posts: 882	240v connection in AT psu I have this PSU which ive pulled apart and now i have to re-attach the mains wiring to the pcb. The problem is i cant remember which way the wires went originally. There is 2 points, one goes directly to the full wave bridge rectifier and the other point goes though this component (i think its a thermister, black blob with NTC written on it) and on to the rectifier. Can anyone help? Last edited by Slain; 25th July 2003 at 6:11 PM.

25th July 2003, 12:04 AM	#2
Rake Member Join Date: Apr 2003 Location: Syd Posts: 2,410	If you are trying to reassemble a PSU and don't even know where to join things / what to do, I would certainly not be plugging it into anything

25th July 2003, 12:19 AM	#3
Gnuthad Member Join Date: Jul 2001 Location: Sydney Posts: 1,638	As above. For the record, however, the active goes direct to the bridge, the neutral goes to the NTC thermister.

25th July 2003, 9:13 PM	#5
D F Member Join Date: Jun 2001 Location: Sydney Posts: 1,308	In my experience there has always been some sort of L and N markings on the PCB

25th July 2003, 9:59 PM	#6
Gnuthad Member Join Date: Jul 2001 Location: Sydney Posts: 1,638	Often, yes but not always. If there is a NTC thermistor on the board though, the neutral will always go to the thermistor. as the thermistor is used to slow down the cold-start inrush current when you plug in the PSU.

26th July 2003, 2:36 PM	#8
Gnuthad Member Join Date: Jul 2001 Location: Sydney Posts: 1,638	Please read replies to the thread before jumping in with your own incorrect claims. The thread has only a handful of replies, there is no chance you could have missed that it has already been established that the NTC thermistor is the component in question, not the fuse. A NTC thermistor has an expoxy coating exactly as described, the fuse has a metal cap on each end of a glass cylinder. With uninformed and obviously incorrect replies such as yours it is little wonder that so many people do the wrong thing when dealing with 240V. Please read the sticky at the top of this specific forum.

26th July 2003, 6:09 PM	#9
larrymoencurly Member Join Date: May 2002 Posts: 216	A NTC thermistor has an expoxy coating I haven't seen that many thermistors, but the small ones were epoxy coated (shiney) while the larger ones, such as those used for on the AC line, had only a ceramic coating (dull). This ATX PSU schematic could help.