Author Topic: Switched Power input issues  (Read 5651 times)

andywragg

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Switched Power input issues
« on: May 06, 2010, 12:20:22 AM »
HI,

I'm having a real problem getting a PSU socket that switches between drycell and line power. The socket I bought (from Maplin) has a steel shell, and although it would be OK for centre pin positive applications, all stomp boxes are centre pin negative. This means that when I connect a PSU to the socket, the shell get's +9v. This would result in a short between the case (ground) and the incoming +9v (wouldnt it?). I'm about to send for a non-switched socket, but this will mean i have to modify the layout so that I cant use an internal dry cell.
Anyone know where I might get a socket that is switched but doesnt have a steel shell? UK suppliers preferred.

pandadandan

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Re: Switched Power input issues
« Reply #1 on: May 06, 2010, 01:29:42 AM »
HI,

I'm having a real problem getting a PSU socket that switches between drycell and line power. The socket I bought (from Maplin) has a steel shell, and although it would be OK for centre pin positive applications, all stomp boxes are centre pin negative. This means that when I connect a PSU to the socket, the shell get's +9v. This would result in a short between the case (ground) and the incoming +9v (wouldnt it?). I'm about to send for a non-switched socket, but this will mean i have to modify the layout so that I cant use an internal dry cell.
Anyone know where I might get a socket that is switched but doesnt have a steel shell? UK suppliers preferred.

Generally, all of the cheapo black generic 9v jacks are switched; wire the ground to the input sleeve; the outermost 9v pin goes to the board and the innermost one gets wired to the battery positive.  Or vice-versa... I forget!  hahaha

andywragg

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Re: Switched Power input issues
« Reply #2 on: May 06, 2010, 01:42:35 PM »
All the plastic one's I've seen only have 2 solder tabs, which makes me think they arent switched.I'm planning a visit to the electronics shop in town tomorrow lunchtime so I'll have a look at what they have in.

Thanks

Andy

scdesigns

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Re: Switched Power input issues
« Reply #3 on: May 06, 2010, 04:12:38 PM »
I've always had problems with the maplin sockets, if you've got an ebay account i would recommend Faith Healers pedal supply (UK based). Their store is at http://stores.shop.ebay.co.uk/Faith-Healer-Pedals__W0QQ_armrsZ1 I use their 2.1mm jacks, L shaped fully exposed jack is Ground, Mid is battery snap and top is your 9v to board.

They are quite big jacks, i measured them at around about 11mm hole diameter (i drill a 12mm , little wiggle).

This is the sellers youtube http://www.youtube.com/user/blondegraemey. he's an avid collector of effects and a bit of a diy'er to.

andywragg

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Re: Switched Power input issues
« Reply #4 on: May 07, 2010, 12:23:59 AM »
Thanks mate,

He's the guy I bought my foot switches from earlier this week. I really need a 2.5mm socket as I already have a supply for my Zoom G1XN multi effects unit.

andywragg

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Re: Switched Power input issues
« Reply #5 on: May 07, 2010, 01:15:21 PM »
Now dont I feel like a dick.

I got a 2.5mm socket. Tried it with my Zoom PSU. My Zoom is 2.1mm. I got another on the way from Maplin as well.

Now where is that facepalm smiley? I could do with a flannel to wipe this egg off my face.

Already ordered the 2.1mm versions from Faith Healer.

CRBMoA

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Re: Switched Power input issues
« Reply #6 on: May 07, 2010, 05:32:15 PM »


That's how we learn. I have lost track of how many times I have been mistaken.

But that icky feeling is sure a good learning tool!

scdesigns

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Re: Switched Power input issues
« Reply #7 on: May 07, 2010, 06:34:25 PM »
I done the exact same, don't worry about it. Go with the 2.1mm from Graham and you'll be good.

zaxza

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Re: Switched Power input issues
« Reply #8 on: May 08, 2010, 02:25:10 AM »
I've always had problems with the maplin sockets, if you've got an ebay account i would recommend Faith Healers pedal supply (UK based). Their store is at http://stores.shop.ebay.co.uk/Faith-Healer-Pedals__W0QQ_armrsZ1 I use their 2.1mm jacks, L shaped fully exposed jack is Ground, Mid is battery snap and top is your 9v to board.

They are quite big jacks, i measured them at around about 11mm hole diameter (i drill a 12mm , little wiggle).

This is the sellers youtube http://www.youtube.com/user/blondegraemey. he's an avid collector of effects and a bit of a diy'er to.

I have been looking for a supplier like this for ages, i've acually seen loads of his videos before. Thanks

scdesigns

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Re: Switched Power input issues
« Reply #9 on: May 08, 2010, 03:44:15 PM »
No problem guys, i know its hard making pedals here in the uk. There isnt a great deal of suppliers or community (well that i know of anyway). If you look around ebay you can find all sorts, i found an amazing ross distortion kit on there, and a nice od250 pcb and numerous other pcbs to say the least.

If you's get stuck just give me a shout, i'll see if i can help you out.

andywragg

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Re: Switched Power input issues
« Reply #10 on: May 08, 2010, 04:00:15 PM »
I got most of the bits from Farnell (IC's, diodes, LED's, Caps and resistors), and Maplin (box, 1/4" Jacks, LED holders, Knobs, and battery snaps) . The only things you cant get there are the TPDT switch and the PSU socket, these you can get from Ebay  (Faith Healer).

I couldn't get a 5k linear pot so I got a 10K and strapped a 10k resistor across pins 1 and 3. I've checked it with a meter and its spot on 0 - 5Kohms.

scdesigns

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Re: Switched Power input issues
« Reply #11 on: May 08, 2010, 05:18:59 PM »
Maplin do have potentiometer's but alas not the 5k, they do a 4.7k however. I use the maplin ones in a pinch and they are about as cheap as most ebay ones aswell at 80p each. Only thing is, they are pcb mounting style pot's and dont have the nice lugs to solder to but with practice will become easy to do if you go that direction.

andywragg

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Re: Switched Power input issues
« Reply #12 on: May 10, 2010, 12:16:28 PM »
Got the ones from faith healer, they turned up this morning. I now have everything I need apart from the PCB.

scdesigns

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Re: Switched Power input issues
« Reply #13 on: May 10, 2010, 04:05:36 PM »
He has super fast postage thats for sure, everything i get is next day here!