Crimp on connector for power main

[Jennifer G]

I think for now I'll jsut buy some spade connectors to get this going today.. from Home Depot.. use a cheap $5 wire stripping tool to crimp .. and then replace later on (soon) with better connectors and perhaps a better crimping tool as well.

 

[Jennifer G]

Hi

Missed the solid core wire, those are not suitable for crimping, but also not suitable for mains connections normally (external connections).

I think the recommended fitment method of solid core to PCB would be screw terminal blocks. Soldering is usually not recommended for this type of wire because of the enormous bending stress and possible failure of soldering joints. I don't know why Antek would use that termination method, it's not a standard type of external termination (it as quite common in the 70s, but most know better). It is convenient for them though.

Well I'll have to take a look at the transformer. Someone mentioned that it is most likely solid core. I'll find out.

 

[simon7000]

Well I'll have to take a look at the transformer. Someone mentioned that it is most likely solid core. I'll find out.

The Antek transformers usually have stranded and tinned wire leads. If you want to crimp these you must cut back the lead a bit to get to plain stranded copper wire. A crimp connection over a tinned lead is unreliable as the solder will cold flow under the pressure of a crimp and become loose with age.

You can solder a tinned lead to a fast-on connector if required. They do make them uninsulated. So then you can use heat-shrink tubing.

If you are trying to get a UL certified assembly you have to use the crimper made for the specific terminal that you have. These crimpers usually start at $200 and up. I have a pneumatic crimper that is great for the heavier gauges of wire.

But for what you want to do, contrary to some others I would solder the terminal and not worry about losing any temper. (This assumes you can solder well and the total time to solder a joint should be 3 seconds.)

 

[Jennifer G]

But for what you want to do, contrary to some others I would solder the terminal and not worry about losing any temper. (This assumes you can solder well and the total time to solder a joint should be 3 seconds.)

Solder to a spade connector to slide onto the IEC ac inet or solder the wire directly onto the IEC?

 

[AndrewT]

I really doubt the primary lead outs on any AnTek are solid wire. This goes against any logic I can think of. Maybe the secondary might be and just for a larger currents on a non-standard product.
please verify stranded wire gauge by stripping the primary wire and report back.

the gauge range determines connector size/color and crimper setting that you use.

Most of the cheaper transformer manufacturers use the solid wire of the winding as the lead out wire.
It is recommended in this Forum and others that these be changed to stranded leadouts, if you are able to get to the start of the leads and able to re-insulate after swapping the cables.

 

[AndrewT]

Solder to a spade connector to slide onto the IEC ac inet or solder the wire directly onto the IEC?

Yes and add a rubber boot over the end, with the tristed pair (L+N) coming out to feed to the transformer. The Earth lead (PE wire) normally comes out separately to be directly connected to the Chassis/enclosure.

If the transformer standed leadouts are long enough, they can go straight into the crimp-ons. But twist these as a pair to minimise loop area.

 

[Jennifer G]

AndrewT,

For my setup, the transformer has two red wires tied together and two black wires tied together, for AC input. So I have to solder each pair to one connector. Do you want me to twist the pair of reds together, and twist the pair of blacks together. Then twist both twisted pairs together as one big twisted cable (consisting of 4 wires) ?

This is my current dangerous configuration, so you can see what I am talking about with respect to the transformer input wires:

An externally hosted image should be here but it was not working when we last tested it.

I am putting this amp in a case today and changing the wiring a bit based on feedback I've gotten over the past months. Like I was told not to tie DC ground to the chassis for example. It is currently.

 

[AndrewT]

Make the input to the transformer a twisted quad.
Power ON via Mains Bulb Tester to check the phasing of the two primary windings before you connect anything else.

Take all the wires off that bolt next to the mains input.
Attach the Mains PE wire to that bolt - permanently.

If you want to connect your Main Audio Ground (MAG) to Chassis to make the exposed conductive parts safe, you can connect ONE wire from MAG to Chassis next to wherever that MAG is located. Do not take the MAG connection to the PE connection.

The secondaries from the transformer to the rectifier should be twisted pairs.
Then from rectifiers to smoothing caps use twisted pairs.
Then from smoothing caps to amplifiers use twisted pairs.

 

[Jennifer G]

Make the input to the transformer a twisted quad.

When you say twisted quad, do I braid them together all at once. Or do I first twist the pairs first then twist those twisted pairs together? If I twist two pairs first (before twisting those together), do I twist a red and black together or a red and red and black/black?

Power ON via Mains Bulb Tester to check the phasing of the two primary windings before you connect anything else.

I don't have a mains bulb tester yet, but why would I need to test this when it's already verified to be working.. i.e. when I transfer the existing setup into the other case? I've been using this transformer for several months as is so far.

What do you mean by "phasing" by the way? Can you explain? I know I have the mains wires connected to the appropriate wires (neutral and hot).

Take all the wires off that bolt next to the mains input.
Attach the Mains PE wire to that bolt - permanently.

This makes perfect sense and will do that on the new case. I guess it doesn't matter if that wire is on the back panel or the base panel near it? There might be an existing hole on the base plate I can use that's near the ac inlet.

If you want to connect your Main Audio Ground (MAG) to Chassis to make the exposed conductive parts safe, you can connect ONE wire from MAG to Chassis next to wherever that MAG is located. Do not take the MAG connection to the PE connection.

This makes sense. I'll try floating it as suggested. Should I connect MAG to signal "ground" (return) and speaker "ground" (return)? I believe this was suggested by Brian at chipamp in his instructions. In fact I believe it says CHG (for chassis ground) on the PCB's.

 

[infinia]

When you say twisted quad, do I braid them together all at once. Or do I first twist the pairs first then twist those twisted pairs together? If I twist two pairs first (before twisting those together), do I twist a red and black together or a red and red and black/black?

Just twist the 2 pairs of red + black separately and then connect them in parallel red to red and black to black.
thusly canceling magnetic fields from equal and opposing currents of each coil.
if the current of the pairs isn't the same, twisting them or 'quad braid' wont be as effective. so just bundle the twisted pairs.

 

[Jennifer G]

Just twist the 2 pairs of red + black separately and then connect them in parallel red to red and black to black.
thusly canceling magnetic fields from equal and opposing currents of each coil.
if the current of the pairs isn't the same, twisting them or 'quad braid' wont be as effective. so just bundle the twisted pairs.

Just so I am clear, you are saying take the two red wires and twist those two red wires together. Do the same for the two black wires. Then run those in parallel? After re-reading what you wrote a couple times, it could be interpreted as twisting a black and red pair together.

EDIT: I am starting to think you mean twisting the red + black. I'd use an ohm meter for continuity test to determine which pairs to twist together right?

 

[simon7000]

Just so I am clear, you are saying take the two red wires and twist those two red wires together. Do the same for the two black wires. Then run those in parallel? After re-reading what you wrote a couple times, it could be interpreted as twisting a black and red pair together.

EDIT: I am starting to think you mean twisting the red + black. I'd use an ohm meter for continuity test to determine which pairs to twist together right?

Twist one red with one black. The ones that are connected to the same primary coil. Twist the other pairs the same but with a slightly tighter twist. Solder these to the IEC connector and cover the entire connector with a piece of heatshrink. That way there is no exposed line voltage terminals.

Now what about a fuse? Is it built into the IEC connector? Main power switch?

 

[Jennifer G]

Twist one red with one black. The ones that are connected to the same primary coil. Twist the other pairs the same but with a slightly tighter twist. Solder these to the IEC connector and cover the entire connector with a piece of heatshrink. That way there is no exposed line voltage terminals.

Thanks, I'll do exactly this.

Now what about a fuse? Is it built into the IEC connector? Main power switch?

It's built into a filtered, switched & fused IEC AC inlet. See the following thread for my reclaimed amp case using this inlet -- just installed it today and I'm proud of the looks of it so far :

http://www.diyaudio.com/forums/chip-amps/291371-flea-market-bargain-enclosure-my-lm3886-4.html

 

[simon7000]

Thanks, I'll do exactly this.



It's built into a filtered, switched & fused IEC AC inlet. See the following thread for my reclaimed amp case using this inlet -- just installed it today and I'm proud of the looks of it so far :

http://www.diyaudio.com/forums/chip-amps/291371-flea-market-bargain-enclosure-my-lm3886-4.html

That cart player in the version with a built in amplifier when it became obsolete was often converted into an amplifier by changing the face plate. The one you have is the player only version. If you want to replace it try a nice looking piece of wood!

PM me your location and I may be able to locate a local source of the old replacement face plate.

 

[AndrewT]

Just so I am clear, you are saying take the two red wires and twist those two red wires together.

No, you must twist a Flow and Return Pair of one winding. It is far easier to just twist all four together, then you are guaranteed to have the Flow and Returns in close proximity.

Do the same for the two black wires. Then run those in parallel? After re-reading what you wrote a couple times, it could be interpreted as twisting a black and red pair together.

EDIT: I am starting to think you mean twisting the red + black. I'd use an ohm meter for continuity test to determine which pairs to twist together right?

Yes, if twisting a pair then you MUST identify the Flow and Return of that Source winding.