How to connect a linear power supply

I know this may sound like a dumb question but i have a Tracopower TML

5 Watt AC/DC power module and i don't know how to connect them to my circuit.

The datasheet is available here

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For the TML 5 Watt there are pins 1 2 3 at the input and 4 5 6 at the output side.

1) What is FG? Where do i connect this? 2) Pin 2 and 3 are both AC inputs which do i connect to line, which do i connect to neutral (from wall outlet)? 3) What is pin 5 (NC)? If i only want +5V do i connect to pin 6 and 5 and if i want +5V & -5V i connect pin 4 and 6?
Reply to
Ant_Magma
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Which TML do you have? Single 5V (05105) or double +/-5V (05205)?

  1. FG means Frame Ground and should be connected to the earth.
  2. The datasheet says pin 2 is AC N(eutral) and pin 3 is AC L(ine).
  3. NC here means Not Connected. This is for the single supply version only and you simply do not use this pin. In this case you will have +5V between pin 6 and pin 4. Pin 4 will connect to your circuit's 0V. For the dual supply version you will need pin 5 to have +5V between pin 6 and pin 5 and -5V between pin 4 and pin 5. Pin 5 will connect to your circuit's 0V.

--DF

Reply to
Deefoo

Hi, Ant. I'm not sure if you actually found the data sheet:

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If you look on page 4 of the datasheet, you see the pinout. On the input side (pins 1, 2, 3),

1 = FG 2 = AC(N) 3 = AC (L)

On the wall outlet, you have Line (pin 3), Neutral (pin 2), and Ground or Chassis/Frame Ground (Pin 1).

On the output side, it depends on the model you purchased. By looking on page 1 of the data sheet, you can see that there are seven 5 watt models. If you've got a TML05105, there's a single 5V output. Pin 5 is common, pin 6 is the +5V. Pin 4 is NC (No Connect). If you've got a TML05205, it has both a +5V and -5V available. For the dual +/-5V model, pin 5 is still common and pin 6 is still +5V. However, on that model, pin 4 is -5V.

Good luck Chris

Reply to
Chris

By the way, this is _not_ a linear power supply -- it's a switching power supply.

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Chris

Reply to
Chris

Mine is a single TML05105.

I think i got the old datasheet coz mine did not have the (L) and (N). So for my case i just connect the pin4 and pin6 to get 5V.

Now another problem. I'm using this PSU for this circuit:

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It's Belfuse's powerline signal coupler. On page 3 (Ethernet product), the PSU is connected parallely after the MOV to the L and N. Here, the Earth of the wall outlet is not used.

So how do i connect FG?

Connect FG and pin2 together and connect them to N?

Reply to
Ant_Magma

Hi, Ant. I would assume there's internal shielding and circuitry in the switch-mode power supply connected to FG that helps reduce EMI/RFI emissions. If this were an actual engineering project, you would have to be very concerned with FCC emissions testing, and this seemingly trivial question would take on a lot of significance. In the real world, this can easily be a project killer, and is one major reason why many engineers use canned switchers instead of just rolling their own for low volume applications.

In a college lab, you won't have the equipment available to measure emissions, and I guess you don't have the time to go down this rabbit trail anyway, so just gloss it. For now, just use a 3-conductor line cord, and connect GND on the line cord to FG.

Remember that, unless you've got a handful of these, you may want to use another method of powering your prototype through the initial stages. Although this switcher data sheet says it's got overload and short circuit protection, a mistake is pretty expensive, particularly if you've only got one of them (another lesson -- in a development project, always get a couple of everything).

Good luck Chris

Reply to
Chris

But in the Belfuse coupler schematics they only use the L and N lines. And the N line in this case is used as the reference potential or ground.

I just want to be sure. Are you suggesting that i use the G line as well just to connect it straight to FG?

Reply to
Ant_Magma

Yes.

Chris

Reply to
Chris

Thanks Chris.

Now another thing, in theory the electronics that i learn on paper, there's always ground for the current to return.

Based on Bel's coupler diagram, i would assume the -Vout of the PSU would be the current's return path where i connect all my grounds to, correct?

If so, now with the extra G line connected to the FG of the power supply, which would be my ground now?

Reply to
Ant_Magma

Pin 1 is FG. That is added on the primary side of the switcher for reasons stated above.

The switch-mode power supply has transformer isolation between the primary and the secondary. For the 5V power supply on the secondary, pin 5 is common or the current return path. There is no connection between the primary side and the secondary side.

Ground means many things in electronics, including the return path for the current from the power supply. FG means frame ground.

There have been many group discussions on s.e.b. about this question. Since you're using Google groups, search the word "ground" in this newsgroup for numerous discussions on this subject.

Chris

Chris

Reply to
Chris

Thanks Chris, but since i'm using the SINGLE version and NC is not connected i should use pin 4 correct?

Reply to
Ant_Magma

Ant, it's all in the datasheet. Here's a sketch (view in fixed font or M$ Notepad):

| | Ground .---------. | (Green) FG| | | >---------o 1 | +5V | | 6 o--------> Your |Neutral AC(N)| | Circuit | >---------o 2 5 o-------->

|(White) | | COM | AC(L)| 4 o No Connect (that means leave it open, don't connect anything) | >---------o 3 | | Line | | |(Black) '---------' | (created by AACircuit v1.28.6 beta 04/19/05

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NC means No Connect. If you're making a perfboard, don't solder anything to pin 4. If you're making a PC board, make a pad to allow the pin to be soldered to the board, but don't connect anything to that pad.

Frequently, NC pins will be used by the manufacturer as test points for QC to check something inside the black box post-production. Sometimes there's actually nothing connected to NC pins. But there's no law that says they can't make another version that uses that NC pin for something else, so always leave it alone. NC means No Connect. Period.

Ant, read the data sheet. If you don't understand it, reread it until you understand it.

Just do the work. There really isn't a substitute, unless you want to subcontract the job to someone else.

Chris

Reply to
Chris

Are we having the same datasheet? Mine only have the specifications and the dimensions.

Sorry Chris, i did not intent look lazy or annoy anyone.

It's just that it's my first time doing such a project and i'm just trying to get everything right before i start soldering and putting it together.

Reply to
Ant_Magma

Hi, Ant. Three days ago I gave you the link to the data sheet:

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which requires two more mouse clicks from the page you referenced. Just look at the posts above this one. Since it's a .pdf file, it also requires the free Adobe Reader, which you can get from adobe.com If you're using M$ Windows, right-click on the link, and click "Save Target As..." instead of just clicking on it.

This fairly complete data sheet goes into more detail than typical on the power supply. There should be enough there to use the AC-to-DC module.

No offense, Ant. Prototyping is a bit of a chicken-egg thing when you're dealing with SMT components, I know. But you're also under deadline. If you don't read the datasheet, you're toast.

Chris

Reply to
Chris

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