[sdiy] Jack insertion detection

[Tim Ressel]

Thanks for all the responses!  Very good point about the -12 volts being 
exposed to the external module. A super large limiting resistor would 
take care of it, but I am wary. Meanwhile, many thanks to Vladimir for 
pointing out the Thonkiconn jacks I am using are available in stereo and 
are the same height as the switched ones. Problem solved.

Thanks everyone! You are all the collectively The Man

--timmers


On 7/23/2018 2:21 PM, Tim Ressel wrote:
> Hello supremely helpful folks!
>
> I've got another challenge: how to detect when a plug is inserted into 
> a jack. These are 3.5mm mono jacks btw. The current method is to use a 
> stereo jack. When a mono plug is inserted the ring connection gets 
> shorted to ground by the sleeve of the plug. This method works well, 
> but the stereo jacks are taller than the mono jacks.
>
> The only jack I can use is a switched mono jack where switched port is 
> tied to the tip port until a plug is inserted. My idea is to use the 
> switch port to feed an out of range voltage to the tip port, probably 
> a negative voltage. Then use a comparator to detect when the tip port 
> goes high.
>
> Any other thoughts?
>

-- 
--Tim Ressel
Circuit Abbey
timr at circuitabbey.com