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geekhack Community => Keyboards => Topic started by: AnteroX on Thu, 24 January 2013, 00:21:26

Title: pcb mounted switches vs plate mounted switches question
Post by: AnteroX on Thu, 24 January 2013, 00:21:26
do pcb mounted switches have more key travel than plate mounted switches?
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: WhiteFireDragon on Thu, 24 January 2013, 00:46:38
Nope, they're exactly the same, except that PCB mounted ones have two little plastic pins that go through the PCB. This is needed to better hold the switch in place since it has no plate.
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: Jmneuv on Thu, 24 January 2013, 06:27:49
The keycap itself never touches the 'floor', so it doesn't make a difference.
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: firebt on Fri, 25 January 2013, 10:30:56
Quote from: WhiteFireDragon on Thu, 24 January 2013, 00:46:38
Nope, they're exactly the same, except that PCB mounted ones have two little plastic pins that go through the PCB. This is needed to better hold the switch in place since it has no plate.

Exactly.  +1.

Also, I would like to include that you can easily use PCB mounted ones (with the pins) on plate mounted, all you have to do is remove the two little pins on the bottom.  However, you can't do it the other way around, as they would wobble like crazy and wouldn't feel solid at all. 

Also, plate mounted is better in terms of solidarity, but they are ultra annoying to mod and remove as you have to take apart the whole keyboard (cover off, connections disconnected, PCB removed, desoldering, etc).  So most people that really like to lube and change springs etc get PCB mounted, although I would highly suggest a plate mounted board. 
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: jdcarpe on Fri, 25 January 2013, 10:35:20
PCB mount vs. plate mount Cherry MX:

PCB mount (has mount pins):
(http://i.imgur.com/SwrsOOT.jpg)

Plate mount (lacks mount pins):
(http://i.imgur.com/dSuNdXW.jpg)
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: firebt on Fri, 25 January 2013, 10:52:56
Quote from: jdcarpe on Fri, 25 January 2013, 10:35:20
PCB mount vs. plate mount Cherry MX:

PCB mount (has mount pins):
Show Image
(http://i.imgur.com/SwrsOOT.jpg)


Plate mount (lacks mount pins):
Show Image
(http://i.imgur.com/dSuNdXW.jpg)


gg.  +1
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: ninjadoc on Fri, 30 August 2013, 13:55:11
I hate to be stupid but I  have some PCB black switches that have two additional metal pins at the bottom of the switch. What are those for?
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: SpAmRaY on Fri, 30 August 2013, 13:58:18
Quote from: ninjadoc on Fri, 30 August 2013, 13:55:11
I hate to be stupid but I  have some PCB black switches that have two additional metal pins at the bottom of the switch. What are those for?

Does it have a diode inside the switch?
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: ninjadoc on Fri, 30 August 2013, 14:06:25
Quote from: SpAmRaY on Fri, 30 August 2013, 13:58:18
Quote from: ninjadoc on Fri, 30 August 2013, 13:55:11
I hate to be stupid but I  have some PCB black switches that have two additional metal pins at the bottom of the switch. What are those for?

Does it have a diode inside the switch?


It must. Have dig out "the Beast" switch tools. According to http://www.cherrycorp.com/english/switches/key/mx.htm it should have a diode. Now for the noob question - what do you need the diode for? I say a thread by Lister I believe on Phantom assembly were he was telling someone that either diodes or resistors were a cause of some keystrike errors. Can you educate me please?
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: whiskytango on Fri, 30 August 2013, 14:14:35
Quote from: ninjadoc on Fri, 30 August 2013, 14:06:25
Quote from: SpAmRaY on Fri, 30 August 2013, 13:58:18
Quote from: ninjadoc on Fri, 30 August 2013, 13:55:11
I hate to be stupid but I  have some PCB black switches that have two additional metal pins at the bottom of the switch. What are those for?

Does it have a diode inside the switch?


It must. Have dig out "the Beast" switch tools. According to http://www.cherrycorp.com/english/switches/key/mx.htm it should have a diode. Now for the noob question - what do you need the diode for? I say a thread by Lister I believe on Phantom assembly were he was telling someone that either diodes or resistors were a cause of some keystrike errors. Can you educate me please?

This article helped me understand it. Diodes come into play when you get to the ghosting / masking part

 http://pcbheaven.com/wikipages/How_Key_Matrices_Works/ (http://pcbheaven.com/wikipages/How_Key_Matrices_Works/)
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: ninjadoc on Fri, 30 August 2013, 14:23:17
Actually the switch only has a piece of wire like a paperclip in the switch. No diode. I will have to message him and see what they came off of. They are cherry, older I believe not "vintage" with the big logo.
Title: Re: pcb mounted switches vs plate mounted switches question
Post by: Daniel Beardsmore on Fri, 30 August 2013, 14:41:39
That's a jumper wire — it helps with PCB routing (laying out all the traces) by allowing two traces to cross over each other. I have those in my G80-3000 — perhaps one day I'll take a picture of one for the DT wiki. Some low-profile Alps switches also have integrated jumper wires in them.

The alternative to jumpers is three-legged (KPT/TEC, Omron B3G-S, Futaba clicky etc) and four-legged (e.g. NMB Hi-Tek) switches, where one or both of the electrical contacts has two legs (this is even mentioned specifically in the patent for the NMB Hi-Tek). This means that you can run a trace into one side of the switch and out the other easily.