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1  Using Arduino / Installation & Troubleshooting / Re: Radio Shack Make:It links are broken - anyone have a good link? on: Today at 09:55:23 pm
Rumor has it Radio Shack USA has gone bankrupt.
Maybe this has something to do with it?.
2  Using Arduino / Programming Questions / Re: Starter Kit, Project 13 on: Today at 07:54:37 pm
sketch_sep15a:3: error: expected unqualified-id before numeric constant
This says line 3
3  Using Arduino / Programming Questions / Re: Starter Kit, Project 13 on: Today at 07:51:43 pm
Add a semi colon  ;
const int ledPin = 12;
4  Using Arduino / General Electronics / Re: 555 resistor value for Tm = Ts on: Today at 07:16:56 pm
Feed the output into a FLip Flop.
5  Using Arduino / Displays / Re: LCD connection on: Today at 01:48:29 pm
Quote
if i run the sketch with no lcd attached then it works fine, as soon as I attach it then it freezes.
As mart256 says.

Show us an image of your wiring.
6  Using Arduino / Programming Questions / Re: i have problem with this arduino coding..im lost... help me please!!!! on: Today at 01:38:45 pm
See:
https://sites.google.com/site/kingauswebpage/my-projects/cannot-find-wconstants-h
7  Using Arduino / Programming Questions / Re: How to detect frequency on: Today at 01:27:12 pm
Take a look at this:
http://www.gammon.com.au/forum/?id=11504
8  Using Arduino / General Electronics / Re: opto coupler Current transfer ratio - very simple explaination? on: Today at 01:23:45 pm
If you want some control, try a H11F1 opto FET.
See As a Variable Resistor or Atomoatic Gain Control section on the data sheet.
https://www.fairchildsemi.com/datasheets/H1/H11F3M.pdf
Also see Resistance vs Input Current graph.
Not really that linear, but not to bad.

9  Using Arduino / General Electronics / Re: LED holder on: Today at 01:11:55 pm
See:
http://www.jameco.com/1/3/led-bezel-panel-mount
10  Using Arduino / General Electronics / Re: HP current tracer on: September 13, 2014, 06:45:44 pm
Quote
More realistically the smallest ferrite bead you can find and carefully grind
it to a C shaped profile (carefully with a Dremel and alumina grinding tool?
- don't inhale the dust!)
Then very fine wire for the coil.

Got some results:
I had a 2 mm by 5 mm bead/rod.
I cut of 1 mm with the suggested Dremel using diamond cut off wheel. Then had 2 mm X 1 mm core.
10 raps of #40 wire with a bit of glue.
Then I cut off some of the core so it looks like a C
Put input into comparator 339.
Fig. 34
http://www.ti.com.cn/cn/lit/ds/symlink/lm339-n.pdf

Going to do some work on a pre-amp.

Quote
[ Actually, a brainwave - use a floppy disc drive magnetic head!  About the right
size I'd think ]
I like this.
Good idea will have to try this also.
11  Using Arduino / General Electronics / Re: HP current tracer on: September 13, 2014, 05:10:59 pm
How to make the ferrite 1.5mm "H" component?
12  Using Arduino / General Electronics / HP current tracer on: September 13, 2014, 04:49:29 pm
I would like to make something similar to the old HP current tracer.
Page 6 shows the concept behind the probe tip.
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1976-12.pdf

Any suggestions on how to make the tip part?
13  Using Arduino / General Electronics / Re: explanation for voltage drop - suggestions? on: September 13, 2014, 12:24:55 pm
What is the resistance of the wire?
If it is not open, you must be wiring it incorrectly or there is a poor connection.
14  Using Arduino / General Electronics / Re: Simple waveform gen for oscilloscope practice? on: September 13, 2014, 12:16:06 pm
For basic usage, that looks like it should suffice.
15  Using Arduino / General Electronics / Re: Simple waveform gen for oscilloscope practice? on: September 12, 2014, 03:53:31 pm
Quote
Can't come much simpler than this I guess?
Agreed

As mentioned you can use an Arduino also. 
Has the power to be programmable (use direct port manipulation).
For example produce 100  -  10uS pulses out every 10 seconds.
Maybe put a Pro Mini in a small box with FTDI out to the case for programming.
Also have a few outputs on a DB-09 female connector.  1HZ, 10Hz, 100Hz etc.
Add some PWM for servos.
Maybe a pot to vary the frequency.

LEDs, Bubble-Luscious ten minute air supply, wheels  smiley-zipper  Sorry caught in the moment.
 
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