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1  Using Arduino / General Electronics / Re: Minimum wire size permissible? on: April 11, 2014, 04:34:45 am
Thanks for your replies. If chassis wiring applies, couldn't I even use 26 AWG wire? It has a chassis rating of 2.2 Amps which would give me plenty of overhead.
2  Using Arduino / General Electronics / Minimum wire size permissible? on: April 09, 2014, 05:07:22 pm
Hi
I'm working on a consumer product and I'm trying to find out what the minimum permissible wire size for my application is. Looking at different AWG charts, I found it a little confusing and I'm not sure which values apply (power transmission or chassis wiring). Some people told me that I should take the value for power transmission but others suggested the value for chassis wiring. The wires need to be as flexible as possible, so I want to make sure that I don't use unnecessarily thick wires.

Here's the specifics. I will have a total of 5 wires bundled in one strand. 3 wires connect to a brushless motor that draws about .3-.4 amps @12V. The remaining two wires are connecting a battery (positive and negative) with a pcb board. They run 1.2 amps @12V. The length of the wires is ca 6-8inches. Insulation type is silicone.

Any input would be apprechiated.
3  Using Arduino / General Electronics / Re: PCB design for Battery Connector? on: November 18, 2013, 04:37:07 pm
The plan is to sell the product eventually, so it's important that it is done properly. I just soldered it directly to the pins for a prototype, but it's not very "clean".
4  Using Arduino / General Electronics / PCB design for Battery Connector? on: November 18, 2013, 01:49:24 am
Hi Everybody
I have a project for which I need to use a battery connector as pictured bellow. The problem is that I can't solder any electric wires directly to the battery connector. I believe the battery connector is designed to be used on a PCB. However, I don't really understand how it is supposed to be fixed on a PCB. Can anybody tell me how such a battery connector is supposed to be attached (looks like you can't just solder it to the board, but I might be wrong)?

Also, I have absolutely no experience in PCB design, but it looks like it should be rather simple to do in one of those free programs. Are there any specific things I have to watch out for? How do I ensure that the two circuits can carry the required amperage?

Bellow you see a picture of the battery connectors and a CAD mock-up of what the PCB is supposed to look like. Also, does anybody know somebody that could make the drawings for such a PCB at a reasonable price? (I contacted a couple design firms, but I can't afford their prices).
Any input is appreciated.
5  Using Arduino / General Electronics / Re: Can't find 7-8.4V DC 1Amp on/off switch on: October 26, 2013, 10:47:54 am
Thanks for all your replies. The Panasonic on/off switches (rocker switches) are a little to big (25mm long), so I'm still looking for a switch.
Using a circuit to do power switching might actually work because the form factor will be very different from a traditional switch.

Are there any off the shelf circuits for power switching? What would such a circuit be called?
6  Using Arduino / General Electronics / Re: Can't find 7-8.4V DC 1Amp on/off switch on: October 25, 2013, 05:40:38 pm
Thanks for the reply.
15mm x 8mm x 10mm or similar would be ideal. Most switches that I could find that where rated for 12VDC to 125VDC had very low amp ratings.
7  Using Arduino / General Electronics / Can't find 7-8.4V DC 1Amp on/off switch on: October 25, 2013, 05:00:53 pm
I'm using a 2S Li-ion battery to power three motors. The battery has about 8.4V fully charged and the motors and electronics draw about 1A of power. I already spent hours looking for a small switch that can be used as the main switch for this set-up. Space is very scares so the more compact the switch is the better (best would be 15mmx8mmx10mm or smaller). I already spent hours looking for such a switch with no success. Am I just looking in the wrong places or does it not exist? (the ones that I found are rated for much higher amperage and therefore are pretty big).
Any help is appreciated.


Looking for:
- 7-8.4V DC 1Amp on/off switch
- rocker, slide or similar type
- the smaller the better
8  Using Arduino / General Electronics / Re: Control very high power LED on: February 28, 2013, 01:50:10 am
I absolutely aware of the potential dangers, which is why I'm in the process of getting IR safety glasses. It's not a laser, but a normal IR LED.
It's similar to what you can see here: http://www.alibaba.com/product-gs/513452759/100W_IR_LED_850_860nm.html

So far this seems to be the simplest solution: "Use a MOSFET to switch it but drive the gate high/low with a second transistor".
Will this work?


Any more suggestions on how to make a simple prototype?
9  Using Arduino / General Electronics / Re: Control very high power LED on: February 26, 2013, 08:14:18 pm
Sounds like quite a design challenge. The OP, because he asked such a basic question, is most likely not capable of such a design and construction effort?

I suspect not.

I think we need more details about his battery and why he wants to use it before we can go any further (hint...)


First of all, thanks for all your replies smiley
I'm actually just trying to find out the max range I can get with an IR LED. I don't want to give away the exact purpose yet, as I might turn it into a real product at some point in the future. My problem is that I don't know a whole lot about electronics, but I would like to at least make a working prototype before I dive deeper into it. I already have a prototype with a 5 watt IR led. I just used a simple transistor and a 12.6 V lipo battery to power it (I use lipos because I'm into RC flying and have them readily available).
I was just looking for a way to easily replace the 5W IR LED with a 100 W LED that I just bought (I don't know why it is considered a 100W led, the specs are only 16V and 3500 mA which comes out to 56 W).
I hope to cover a large area (like a basketball court) with the IR LED. The 5W LED is strong enough to cover my whole living room with a signal, but I don't know how well it scales up. I know that I could just use an RF module to get better range, but this specific project wouldn't work with RF.
Since it is just a prototype to find out how large of an area I can cover with a 100W IR led, I just need to make it work for a few minutes at the time. I'm not too concerned with durability etc. If anybody has a really simple solution, that would be perfect...
10  Using Arduino / General Electronics / Control very high power LED on: February 26, 2013, 04:36:56 am
Hello Everybody
I'm trying to find out what the best way would be to control a 50-100 Watt IR led with the arduino. The IR led is pulsed at 38 khz so the switching will have to be very fast. I would like to use a 16.8 volt lipo battery as my power source. The LED itself runs of 16-19 Volts, 3500 mA.
I was thinking if there's some transistor that can handle this or what would be my best option?
11  Using Arduino / Programming Questions / Re: How to create a 38 Khz pulse with arduino using timer or PWM? on: September 24, 2012, 08:48:05 pm
That's awesome, I can't thank you enough. Looking at what it took, I don't think I would have been able to write this myself anytime soon. If I can ever return a favor, let me know (I don't have any programing knowledge but a lot of video/photography knowledge). Thank you so so much again... I really appreciate it smiley
12  Using Arduino / Programming Questions / Re: How to create a 38 Khz pulse with arduino using timer or PWM? on: September 23, 2012, 06:13:22 pm
Hello Everybody
I have a little issue, and I just can't get it worked out. I already spent a good amount of time on it but I'm still super new to the Arduino board.

I would like to pulse width modulate a 38kHz carrier signal at 500hz, and adjust the duty cycle of the 500hz signal by reading a value from a potentiometer (value between 256 and 0 (100% to 0% duty cycle)).

So far, I came up with the code bellow, which does the following: It uses the tone() command to output a 38kHz signal on pin 11 and uses the delayMicroseconds() command to modulate it at 500hz. By
adjusting the delays for the on/off period of the 38kHz signal (by using a value I get from the Potentiometer), I can adjust the duty cycle of the 500hz modulated signal. (In the example below, I have 2048 increments by which I can adjust the duty cycle, but I would only need 256.)  

Code:
void loop () {
  
Bval = analogRead(PodPin) * 2;
//(Read Potentiometer, then multiplay value by x2 and store it in "Bval" (Value will be between 0 and 2048)

tone(11,38000);
//create 38kHz signal on pin 11)

delayMicroseconds(Bval);
//delay for "Bval" microseconds

noTone(11);
//turn off 38kHz signal on pin 11

delayMicroseconds(2048 - Bval);
//delay for "2048 - Bval" microseconds.

}

For some reason, my code doesn't work very reliable. My guess would be that everything is extremely "time sensitive" and by doing it with "delays" it will never be very accurate. I think it should be possible to do it much more reliably with timers but I just can't get it to work (I tried to play with code posted above by Nick Gammon, but didn't have much luck yet). Any chance somebody could help me on this? I would greatly appreciate any input...

PS: I have an Arduino Uno
13  Using Arduino / Sensors / Re: IR Sensor and continuous 38kHz signal... not working on: August 09, 2012, 02:17:52 pm
Thanks so much for the info.... Ordered those smiley
14  Using Arduino / Sensors / IR Sensor and continuous 38kHz signal... not working on: August 07, 2012, 05:00:25 pm
Hello...
I created a very simple set-up but for some reason I can't get it to work.

I have an IR LED that outputs a continuos 38kHz signal (LED is on and pulsates at 38kHz).
I then have a normal LED hooked up to an IR sensor. Since the sensor receives a continuos 38kHz signal, I would expect this LED
to be on continuously. Unfortunately this is not the case. For some reason it only turns on (flashes) when the sensor receives
a "intermitted" 38kHz signal, as when for example a remote control code is transmitted.

My questions: What might be the issue here, and how can I get the LED to light up continuously in the presence of a continuos 38kHz signal?
15  Using Arduino / General Electronics / Re: IR controlled LED color mixing... on: June 22, 2012, 02:04:52 am
Thanks for the link. I thought it should be possible with a normal TV remote protocol like the X-Sat or Mitsubishi protocol, since some of them can transmit 32 bit of data, which would be enough for my application...
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