Electronics > Projects, Designs, and Technical Stuff
A 6,35mm / 1/4" Telefone Jack with a normaly open Contact/Switch
jhpadjustable:
MOSFET gates leak fractions of a nanoampere. 37µA seems unnecessarily high. You should be able to make that pullup much larger (megohms) without any problem. Clean all flux residue thoroughly.
With an appropriate bracket and any open-frame panel-mounted jack, you could use a "basic switch" aka snap-action switch (similar to mouse buttons), with a roller actuator such as Omron SS-5GL2, to sense the presence of a plug. With insulation, you could also add your own contact to the sleeve to any open-frame panel-mounted jack.
Someone:
--- Quote from: Detzi on November 29, 2019, 09:35:01 am ---
--- Quote from: jhpadjustable on November 29, 2019, 08:54:55 am ---The 13 appears to be a stock Digi-Key item.
Switchcraft nomenclature for their 1/4" phone jacks seems to use a 3 (not 3A, 3B, 3C, 3D, 3E, etc.) to indicate an isolated "make" circuit upon connection. So, the N113X (lead-free suffix, enclosed prefix) would also have the "make" switch needed. Does it need to be capable of stereo output, or does it just need to leave the ring connection alone?
--- End quote ---
It should be able to drive my Stereo Headphones with a Mono signal so R+L receive the same input. And it should survive someone pluggin in a Mono-Plug and putting out a single channel mono signal to it. I haven't settled on a discrete Output configuration since i dont know what the options are, yet.
--- End quote ---
Thats not a preamp anymore if its driving headphones.
Detzi:
--- Quote from: jhpadjustable on November 29, 2019, 09:52:30 am ---MOSFET gates leak fractions of a nanoampere. 37µA seems unnecessarily high. You should be able to make that pullup much larger (megohms) without any problem. Clean all flux residue thoroughly.
With an appropriate bracket and any open-frame panel-mounted jack, you could use a "basic switch" aka snap-action switch (similar to mouse buttons), with a roller actuator such as Omron SS-5GL2, to sense the presence of a plug. With insulation, you could also add your own contact to the sleeve to any open-frame panel-mounted jack.
--- End quote ---
Thank you for the link to the switch i did not know it is called "Snap Action" :D of course i can make the pullup larger.
Shown is the Voltage at the Gate over time.
But if i do so i fear that noise coupling could start to actuate my PMOS-switch. 10 Meg means 100nA coupled noise will create 1V drop, this may be too sensitive. But i have no experice values abou what to expect. either
--- Quote from: Someone on November 29, 2019, 10:08:44 am ---
--- Quote from: Detzi on November 29, 2019, 09:35:01 am ---
--- Quote from: jhpadjustable on November 29, 2019, 08:54:55 am ---The 13 appears to be a stock Digi-Key item.
Switchcraft nomenclature for their 1/4" phone jacks seems to use a 3 (not 3A, 3B, 3C, 3D, 3E, etc.) to indicate an isolated "make" circuit upon connection. So, the N113X (lead-free suffix, enclosed prefix) would also have the "make" switch needed. Does it need to be capable of stereo output, or does it just need to leave the ring connection alone?
--- End quote ---
It should be able to drive my Stereo Headphones with a Mono signal so R+L receive the same input. And it should survive someone pluggin in a Mono-Plug and putting out a single channel mono signal to it. I haven't settled on a discrete Output configuration since i dont know what the options are, yet.
--- End quote ---
Thats not a preamp anymore if its driving headphones.
--- End quote ---
I don't know about the terminology here because i don't usually do audio stuff, for me it is a preamp because it needs to preamp the pezo element in my e-Violin, it also should drive headphones...to be fair, i mentioned this in reply#3
--- Quote from: Detzi on November 28, 2019, 03:06:36 pm ---I did not mention that i'd like to use the preamp either to connect to my HiFi-Receiver, or to my Headphones. Which guarantees a stereo Plug is used sometimes.
--- End quote ---
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