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by 52midnight
Thu Feb 16, 2017 11:29 pm
Forum: Mathematica
Topic: An equation to generate the output of a driven RC circuit.
Replies: 11
Views: 12696

Re: An equation to generate the output of a driven RC circui

Many thanks, jojopi. An unexpected gift!

> Everything is a function of time only

Yes, that's the quickest path to a solution that I anticipated, but didn't know how to find it.

I'll post back after I fire up the Rpi and try it out.
by 52midnight
Thu Feb 16, 2017 10:54 pm
Forum: Mathematica
Topic: An equation to generate the output of a driven RC circuit.
Replies: 11
Views: 12696

Re: An equation to generate the output of a driven RC circui

I posted to a likely looking maths forum in the hope of finding a tame boffin who speaks the vernacular: http://mymathforum.com/physics/339093-equation-generate-output-driven-rc-circuit.html Meantime, it may be that any solution is going to be complex. If you look at what seems to be simple - the eq...
by 52midnight
Thu Feb 16, 2017 8:34 pm
Forum: Mathematica
Topic: An equation to generate the output of a driven RC circuit.
Replies: 11
Views: 12696

Re: An equation to generate the output of a driven RC circui

Tried editing the above but it didn't happen. So ... Better to say that there are two independent variables - time and current - and one dependent variable - the voltage across the capacitor . The current into and out of the cap is determined by the drive voltage applied to the resistor , which alte...
by 52midnight
Thu Feb 16, 2017 8:09 pm
Forum: Mathematica
Topic: An equation to generate the output of a driven RC circuit.
Replies: 11
Views: 12696

Re: An equation to generate the output of a driven RC circui

> can be easily solved for some situations like a stead-state Vo or a know frequency. Quite so, but this has two independent variables - time and voltage - and is thus a more complex case than those typically found in textbooks and undergraduate courses. There may well be standard solutions but I ha...
by 52midnight
Thu Feb 16, 2017 5:33 pm
Forum: Mathematica
Topic: An equation to generate the output of a driven RC circuit.
Replies: 11
Views: 12696

Re: An equation to generate the output of a driven RC circui

The filter analyses I've seen treat the RC combination as a frequency-dependent network, and thus use the frequency domain as the abscissa rather than time, as I require. The other analyses use a "step" approach. They use starting conditions to plot the v:t curve using the standard exponential funct...
by 52midnight
Thu Feb 16, 2017 7:52 am
Forum: Mathematica
Topic: An equation to generate the output of a driven RC circuit.
Replies: 11
Views: 12696

An equation to generate the output of a driven RC circuit.

This is more about mathematics and electronics, but I'd like to use Mathematica to generate the graphs I need. It's probably something that others might also find useful. Given: a voltage source Vo with an output of 0V - 5V at a frequency Fclk. One end of a resistor R is connected to Vo, the other e...
by 52midnight
Fri Nov 04, 2016 1:52 am
Forum: Advanced users
Topic: Is device ID written into system ROM?
Replies: 2
Views: 599

Re: Is device ID written into system ROM?

Thanks, Scotty. Quick solution.
by 52midnight
Thu Nov 03, 2016 8:36 pm
Forum: Advanced users
Topic: Is device ID written into system ROM?
Replies: 2
Views: 599

Is device ID written into system ROM?

I have a very early Model B (256MB RAM) and would like to identify it as accurately as possible.

Is there a device ID code or something similar in the system ROM or elsewhere that I can use for this?
by 52midnight
Tue Nov 01, 2016 3:57 am
Forum: Other projects
Topic: Rpi wifi camera.
Replies: 3
Views: 839

Re: Rpi wifi camera.

Thanks to both - a very good start. Will post back when I've investigated.
by 52midnight
Mon Oct 31, 2016 4:18 pm
Forum: Other projects
Topic: Rpi wifi camera.
Replies: 3
Views: 839

Rpi wifi camera.

I'd like to set up my Rpi as a wifi camera pointing down at my workbench so that my students can see what I'm doing on their laptops. Since this is my first Rpi project, I'm not up to speed with what's out there. Can anyone suggest what cameras are available, what wifi attachments, software for the ...
by 52midnight
Mon Oct 03, 2016 2:56 am
Forum: Troubleshooting
Topic: Wifi does not connect.
Replies: 2
Views: 501

Re: Wifi does not connect.

Great! Thanks for a succinct and practical reply. The Rpi is in for a grease and oil-change, so I'll post back when it's out of the garage.
by 52midnight
Sun Oct 02, 2016 11:41 pm
Forum: Troubleshooting
Topic: Wifi does not connect.
Replies: 2
Views: 501

Wifi does not connect.

Raspberry Pi Model B dated 2011, 256MB RAM. New download of PIXEL 2016-09-23. Plugged in a USB wifi dongle. Right-clicking the Network tray icon brings up the preferences dialogue. Set it to Configure - interface - wlan0 with the autoconfig box ticked. No result. Nowhere to put in the PSK. My tablet...
by 52midnight
Fri Apr 04, 2014 9:56 pm
Forum: General discussion
Topic: Proposal for Rpi I/O connector kit.
Replies: 0
Views: 672

Proposal for Rpi I/O connector kit.

I'm designing a mating board (add-on) for the Rpi and would like to arrange for it to be flush with the top of the highest Rpi component, the USB connector. Given that the height of available sockets varies somewhat, this might take some browsing of data sheets. I'm also including a USB hub on the m...
by 52midnight
Fri Apr 04, 2014 8:41 pm
Forum: General discussion
Topic: Socket for the IO header.
Replies: 2
Views: 813

Re: Socket for the IO header.

Many thanks! A big help.
by 52midnight
Fri Apr 04, 2014 1:46 am
Forum: General discussion
Topic: Socket for the IO header.
Replies: 2
Views: 813

Socket for the IO header.

Can anyone recommend a part number and/or supplier of a mating socket for the 26-pin I/O header?

With thanks for all replies.
by 52midnight
Mon Nov 12, 2012 9:34 pm
Forum: Beginners
Topic: UK characters appear when setting up Evolution
Replies: 5
Views: 1002

Re: UK characters appear when setting up Evolution

Have now converted to the US English locale with UTF-8 encoding and the appropriate 105-key board, and all is behaving according to Hoyle.
by 52midnight
Mon Nov 12, 2012 8:18 pm
Forum: Beginners
Topic: UK characters appear when setting up Evolution
Replies: 5
Views: 1002

Re: UK characters appear when setting up Evolution

Yep, and good on the Poms - it's great product. Here in Oz we seldom see anything other than a US kbd, so it's not an issue I've had much experience with - likewise others, I'd guess. I'm putting together an Rpi subsite for my website, so I'm asking a few 'stupid' questions to make sure my assumptio...
by 52midnight
Mon Nov 12, 2012 7:16 pm
Forum: Beginners
Topic: UK characters appear when setting up Evolution
Replies: 5
Views: 1002

Re: UK characters appear when setting up Evolution

Ah, OK, didn't realize that the default was UK, since the kbd default seems to be 105 key which (in my experience) has a hash sign as a shifted three rather than the UK 'L' pound sign. Also, I've never seen any mention of this in the docn, so I assumed the US default as is usual. Thanks; will try ch...
by 52midnight
Mon Nov 12, 2012 1:01 am
Forum: Beginners
Topic: UK characters appear when setting up Evolution
Replies: 5
Views: 1002

UK characters appear when setting up Evolution

I've just re-installed Rpi Raspbian for the third time (checking things out) and deliberately left the 'locale' setting in 'raspbi-config' untouched (past experience). I'm now trying to install Evolution, and when I enter my email address I get a UK substitute for the @ sign, which makes further pro...
by 52midnight
Sat Nov 10, 2012 1:13 am
Forum: Beginners
Topic: Can't ping router.
Replies: 10
Views: 7054

Re: Can't ping router.

Sorry guys, my mistake. Figured it was, but since I couldn't find any relevant material I thought I'd post it for future reference by others. The problem was in the router (as many of you will have suspected). I'd set up IP-MAC binding for my other machines, and it had been working fine. However, wh...
by 52midnight
Fri Nov 09, 2012 8:31 pm
Forum: Beginners
Topic: Can't ping router.
Replies: 10
Views: 7054

Re: Can't ping router.

Tnaks for the prompt reply. As requested: pi@raspberrypi ~ $ sudo ifconfig eth0 Link encap:Ethernet HWaddr b8:27:eb:55:f5:8b inet addr:192.168.1.103 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:887 errors:0 dropped:0 overruns:0 frame:0 TX packets...
by 52midnight
Fri Nov 09, 2012 3:51 pm
Forum: Beginners
Topic: Can't ping router.
Replies: 10
Views: 7054

Can't ping router.

I've just fired up my new Rpi and am suitably impressed. My ethernet router has assigned it an IP address (192.168.1.103) and ifconfig verifies this. However, I can't ping the router, and of course there's no connection via Midori.

Is there a firewall or other impediment to LAN connection?

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