ac adapter and plug

Started by rhdwave, November 11, 2007, 09:47:09 PM

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rhdwave

I just want to start by thanking everyone for their help with everything on this board.  I have gotten great responses to just about everything i have asked.  This forum is an amazing place.  Having said that, here's a couple of more problems i'm having:


I have this adapter: http://www.mouser.com/catalog/specsheets/164124.pdf
and this plug: http://www.mouser.com/catalog/specsheets/KC-300854.pdf

I have two questions:

1st, when i plug the wall wart in and then connect to the female plug, if i fully connect i get no voltage on the other end, if i connect til the male end connects with the last ring but not beyond i get power.

2nd, what is the correct way to measure ac voltage, and then dc voltage after the diode bridge (this is for the neovibe)?

Much thanks for any repsonses!!!

Is this the correct adapter combined with the female plug?

rhdwave

I'm wondering if it could be something really simple: Could it be the fact that the jack is mono? Do i need a stereo jack for an ac adapter? For the Neovibe, the jack is not supposed to touch the chassis and shouldn't be grounded.  So should i be using a stereo jack and just connecting the tip and ring? ???

frankclarke

#2
A voltmeter will have AC and DC settings, try it on known voltages. I don't understand the issue you are having there.
If the connector doesn't work full in, it is probably wrong. You have a workaround until you get the right part.
If you have a resistance meter with you in the store, you can measure continuity to see if it works with the jack, if it isn't in a blister pack.

rhdwave

Thanks Frank...you're right about it being the wrong part...but i'm just wondering what the right part would be.  I'm thinking at this point it must be a stereo connector, and just leave the sleeve alone, but i'm not sure.  What i have now is a mono connector so i'm assuming the two solder tabs are tip and sleeve.  And for measuring AC voltage...  should i still have the black probe grounded and the red on the area i'd like to measure and just set the meter to AC?

dxm1

You don't need a reference to ground to measure AC. Put one probe on each side of the AC - it doesn't matter which, red or black. To measure your wall wart, put one meter lead on the plugs tip, the other on the sleeve. With the meter set to show AC volts, you should see what your wart is putting out.

rhdwave

Thanks dxm1 that clarifies things a lot.  So do u have any clue why these two would not be compatible?

I have this adapter: http://www.mouser.com/catalog/specsheets/164124.pdf
and this plug: http://www.mouser.com/catalog/specsheets/KC-300854.pdf


dxm1

No, they look compatable. Measure the AC voltage on the wall wart's plug, to make sure that it's working (as well as your measuring technique). Then, plug into the jack and make a measurement between the jack terminals.

rhdwave

Okay, The wall wart is getting about 19.2Vac.  When i connect it to the jack and measure the ac voltage on the two solder tabs, as long as i don't fully plug it in, i'm getting the same numbers.  If i push the connection all the way forward, i get nothing.  There must be something shorting i guess.  It's really strange cause i tried this with two separate wall warts of the same design as well as two separate jacks and got the same results.   ???

dxm1

Well then, it looks as if your jack is NOT compatible. It may be designed for shorter length plugs. If you look at the cross section drawing in the PDF you linked, you'll see a spring steel 'finger' inside the jack. This is designed to catch the tip of the plug.

If the plug is too long, when you insert it all of the way into the jack, the tip passes over the finger and the finger makes contact with the plug's sleeve. Then, both jack terminals  are connected to the sleeve.

To test this, unplug the wart from the wall. Set your meter to read continuity (or low Ohms). Insert the plug all of the way into the jack, and measure both terminals. If you have continuity, that is your problem.

Also, you mention that you read AC if you don't seat the plug all the way. Do you feel a 'click' or detent when the plug is partially inserted? This would also indicate too short of a jack.

If you look at the specs for different DC jacks, you'll find that they are offered for different lenght plugs (while still being 2.5 mm diameter).

Since the PDF for the wall wart doesn't specify the plug dimensions, you could call Mouser and ask one of their sales techs. Or, if you have a local well stocked electronics supplier, take your meter and wart in and measure all they have in stock.

rhdwave

Thanks again dxm1!!! Okay, here's the latest: This seems strange: I actually have continuity on the two sections of the plug itself.  I tested both wall warts and they are the same.  When i insert the plug into the jack all the way, it is exactly opposite from what was expected, in that there is no continuity.  Yes, there is a click before the plug reaches the end of the jack, and this is where i have found that the plug and jack gives out voltage and seems to work correctly.

So, i guess either way, it is the wrong jack for the plug.  I really appreciate all your help, this has been driving me crazy.  I think i'm going to call up mouser and see what they say.  I'll let you know how that goes.


rhdwave

Okay, called Mouser...they're not sure, but said they will research it and email me...

dxm1

Quote from: rhdwave on November 13, 2007, 12:30:09 PM
This seems strange: I actually have continuity on the two sections of the plug itself.  I tested both wall warts and they are the same.

Not strange at all. This is an AC adapter, so the tip and sleeve of the plug connect to each end of a transformer winding - essentially a long wire. If there was no continuity, you would have a problem.  :icon_cool:

QuoteWhen i insert the plug into the jack all the way, it is exactly opposite from what was expected, in that there is no continuity. 

That is strange - not what I would expect. At least you're on the right track. See if Mouser can recommend a proper jack.