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166  Using Arduino / Project Guidance / Re: arduino +100Mhz radio jammer on: February 24, 2013, 05:49:22 pm
Quote
Is that sufficiently concise to end the shouting match?
He is taking freedom of believe to a level that is beyond belief.

The highest level of which is just plain ignorance.
167  Using Arduino / Project Guidance / Re: arduino +100Mhz radio jammer on: February 24, 2013, 01:20:46 pm


I think I can hear them starting to rattle and shrink already smiley-wink



That's the best macro of a pair of BB's I've ever seen!
168  Using Arduino / Project Guidance / Re: arduino +100Mhz radio jammer on: February 24, 2013, 10:22:36 am
This is the "Project Guidance" section, so if I picked the wrong band to mess with jamming to learn from then tell me.
Okay, now you're talking. There is an unallocated band between 3kHz and 6kHz. Knock yourself out.

Yes they know I have a brass set and the one is bigger then [sic] the other two.
And pay attention in grammar class this term.
169  Using Arduino / Sensors / Re: Frequency input issue for tachometer on: February 24, 2013, 09:59:43 am

Sorry, I mean you are supplying its input with many times more current than necessary. It probably has an Hfe of greater than 1000 at the collector current you will get with a 10k collector resistor.

Ok, much clear for me now smiley

Thank you. I'll let you know if it's working after modifying it.

You're welcome.
Definitely, keep us informed.
170  Using Arduino / Sensors / Re: Frequency input issue for tachometer on: February 23, 2013, 06:26:26 pm
What do you mean by 'overdriving the darlington' ? My english is not so good  smiley-red

Put the filter in place of the resistor was already in my plan smiley

Sorry, I mean you are supplying its input with many times more current than necessary. It probably has an Hfe of greater than 1000 at the collector current you will get with a 10k collector resistor.
171  Using Arduino / Sensors / Re: Frequency input issue for tachometer on: February 23, 2013, 06:01:36 pm
You are really overdriving the darlington if your input level is 12V. You could put the filter in place of the 1k resistor and kill two birds with one stone.
172  Using Arduino / Sensors / Re: Sensor's Voltage Supply? on: February 23, 2013, 10:18:49 am
Hi!

Thanks for your reply. So at this way I should install 6 wires alarm cable: +-5V, Feedback, Alarm and a power supply tha monitor the output.
This maybe is more complicated than adding 5V voltage regulator to the end line (just before the sensor) and we can use 4 wires alarm cable.
Anyway your solution is one possible option.

regards

Make sure you observe the voltage regulator data sheet recommendations concerning long supply lines and input capacitance.
173  Using Arduino / Sensors / Re: Sensor's Voltage Supply? on: February 23, 2013, 09:18:50 am
Hi!

Arduino Sensors works with DC power, example 5v. In long lines (long cables example 50m) the voltage will drop down and the sensor may not work good properly. What can we do to send exactly 5V to the sensor.

for example if I have a MQ-2 gas sensor that it needs exactly 5V, should we put a 5V power regulator (exa. 7805)?
should we power the sensor from the arduino or from an external power source?

Thanks and regards!

You can use a power supply that has remote sense capability. It will require two more wires in your cable. I have used this technique with strain gauge pressure transducers and 50m cables.
174  Using Arduino / Microcontrollers / Re: Program Gertboard's ATMega328P directly on: February 23, 2013, 08:05:48 am
I do all my Arduino IDE programming on a Mac because it is much faster than doing it on the RPi and then sftp it to the RPi for programming the ATmega 328 on the Gertboard. That might be acceptable for you as well. Otherwise, you're probably going to have to put a bootloader on the chip or get an AVR ISP programmer and use avrdude.
175  Using Arduino / General Electronics / Re: ULN2803A continuous current on: February 23, 2013, 07:48:36 am
The TI data sheet for the ULN2803A shows a total substrate-terminal current of -2.5A. I think power dissipation will be the limiting factor, however, if you operate it continuously.
176  Using Arduino / General Electronics / Re: Would this circuit work? on: February 22, 2013, 10:34:56 am
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And if not, why?

Simple, that output of the amplifier after the series 50 ohm resistor is shown being wired to ground, thus no current can flow out the antenna connection.

Lefty



That's to impedance match the grounded antenna on the input.  smiley
177  Using Arduino / General Electronics / Re: resonator vs crystal on: February 22, 2013, 10:28:50 am
The ad I saw online lists them as Gheo Electronics Arduino Unos.

According to the e-mail I got from Arduino, GHEO Electronics is authorized and so is Microcenter.

Good sleuthing! Good price too.
178  Using Arduino / General Electronics / Re: Would this circuit work? on: February 22, 2013, 10:23:32 am
This definitely won't work as you've left out the Arduino.
179  Using Arduino / Project Guidance / Re: arduino +100hz radio jammer on: February 22, 2013, 09:48:36 am
It's illegal.

Moderator edit: tags corrected (hopefully)
180  Using Arduino / General Electronics / Re: resonator vs crystal on: February 22, 2013, 09:17:42 am
The ad I saw online lists them as Gheo Electronics Arduino Unos.
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