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General Category => General Discussion => Topic started by: RealRiot on June 25, 2012, 00:11:02 AM

Title: Paranormal Tools
Post by: RealRiot on June 25, 2012, 00:11:02 AM
Hi everyone , As you can tell I am very new here and love the site.! I am a paranormal investigator, For those skeptics out there reading this . We all have our thing. Besides I am confident that the administrator of this forum would like me to keep it on topic.

I am Working on an Infrared Illuminator. The Illuminator consists of 24 Infrared LED's 850nm. Specs are as follows: 5mm, Forward voltage 1.5-1.7, Forward current constant 60mA , Max pulse current 120mA peak at 10%, Supply Voltage, I am using 4 AA batteries 6 Volts. I would like to pulse this array at the 120mA max.

I had been looking at the 555 timer circuits that are for dimming but can not get the values correct for stable operation. without the potentiometer.

I am not very good with calculations but I can follow circuit diagrams and even design my own traces. That's about my limit. Please don't ask me to calculate anything. I will learn.

Also I would like to add, The paranormal field can become a very interesting and fun topic. Not only does it reflect on Science but on electronics as well. We use such devices as EMF meters, Full spectrum lighting devices, EVP Recorders, EM pumps, not to mention other related gadgets. Any paranormal investigator will tell you there is always room for improvement when it comes to those tools of the field as well as room for new devices that would assist in the paranormal.

Paranormal investigators have been around for a very long time. We have not yet even scratched the surface to understanding it.  There are hundreds of thousands of us that dedicate a great deal of time and money learning, researching, investigating experiences that people have had or are having. The better our tools the closer we get to understanding and reaching the ultimate conclusion. Is there life after death.? Questions and beliefs that have been around for thousands of years.
Title: Re: Paranormal Tools
Post by: kam on June 25, 2012, 11:54:41 AM
Hello realriot....

what is a paranormal investigator doing really?  ??? ???

check out this link for your pulser:

http://www.pcbheaven.com/drcalculus/index.php?calc=555astable (http://www.pcbheaven.com/drcalculus/index.php?calc=555astable)
Title: Re: Paranormal Tools
Post by: RealRiot on June 26, 2012, 03:16:26 AM
Paranormal investigators are just people that like to play in the dark and talk to things that are very possibly not there. We depend on and use devices that most people know nothing about. Such as Infrared lighting, Full spectrum cameras, EVP recorders. Etc. Many of us take a great deal of pride in the toys that we use to play in the dark with.

Getting back to the link. I am not really sure how to use the calculator based on the infrared diodes and there voltages. I would probably have better luck at deciphering the Human DNA chain.  That would probably be equivalent to the chances of my having tea and crumpets with someone that has been dead for a few hundred years. Does that help.   ???

Tweeted your site and noticed your trade. I am an Electrician, My duties include Pipe bending, Wire pulling, ditch digging and from time to time I experience electric shock therapy which is not voluntary.
Title: Re: Paranormal Tools
Post by: kam on June 26, 2012, 09:40:11 AM
You will have  more problems with your design, and the 555 is the least. But first regarding the pulser. First you need to declare, what will be the ON time and what will be the OFF time, both in miliseconds. Then i can tell you the 555 part values.

BUT

You will definitely need to make a constant current driver for the LEDs. I cannot help you with this very much, because of one thing: The LED specifications are always approximating values...
The problem is that as voltage drops from your supply, the same will happen with the voltage across the LED. But the LED intensity is exponentially related to the voltage. So, 0.5 volts less means less than half the LED brightness... You will therefore need to get a breadboard and make some tests. And you need to read this:

http://www.pcbheaven.com/userpages/LED_driving_and_controlling_methods/

And more specifically this:

http://www.pcbheaven.com/userpages/LED_driving_and_controlling_methods/?topic=worklog&p=3

By setting the proper RE, you will get your 120mA of current

Then you can inject your pulses like this:

http://www.pcbheaven.com/userpages/LED_driving_and_controlling_methods/?topic=worklog&p=5

And get the desired pulsing 120mA.


Anything less than this will result into something NOT reliable for battery operation, since battery voltage drops if a lot of current is required

The 24 LEDs i suggest you connect them into strings of 2 LEDs. so you make 12 strings of 2 LEDs in series, and then you connect these strings in parallel. IMPORTANT is that you will use balancing resistors in each string. 1/10 of the voltage drop must occur on the resistor, that is 1.7 x 2 = 3.4/10 = 0.34 volts, at 120mA you need a resistor R = 0.34/0,12 - 2.8 Ohms, so you can use a 2 Ohms resistor or 2 resistors of 1 Ohms each. You will have to connect these resistors in series with each led string...






Title: Re: Paranormal Tools
Post by: RealRiot on June 26, 2012, 18:58:03 PM
 Interesting point ! When referring to the on and off time how would you calculate pulse time to a point where the actual pulse can not be seen with the eye.? I can imagine the pulse would need to be fast enough to not be noticeable but yet be effective to prolong the life of the LED. I guess I should be asking if the 555 is capable of such a thing.?

As Voltage/Current is drained, What changes take effect in regard to the ON/Off pulse time.?
In general even with a constant current driver as I loose supply power this will reflect (eventually) in pulse time.

OK, Let me ask you, Given The LED's based on the specifications. With your knowing that you need at least a 10-20 foot reach in the dark taking distance into the equation so that your night vision camcorder can pick up the infrared light. And you need it to be mounted to the camera for portability. Also taking into account the life term of your power supply in which you would like it to last as long as possible. What would be the first calculations you would make.?

Title: Re: Paranormal Tools
Post by: kam on June 27, 2012, 17:49:00 PM
Oh well, 4mSec period is for me the minimum period for the eye not to see the flickering. But i have never work with IR LEDs and camcorders so my experience is next  to nothing.
The 555 can easily achieve this frequency, since it is around 250 Hz... It can go much higher. But the frequency will change if the supply voltage is changed, not very much, but it eventually will change. So go to higher frequency and this change won't have an affect. Also, 555 draws some 4mA by itself which is not very good for battery powered applications.

If i were you, i would make a boost SMPS and i would try to have 2 strings of 12 LEDs each, powered with 20 volts from the 4 batteries... This is probably the most efficient way.

Why do you want to pulse the LEDs?
Title: Re: Paranormal Tools
Post by: RealRiot on June 27, 2012, 21:38:38 PM
Mainly, the brighter they are the greater the range.  An infrared would not last very long running them constant at 80% or above . They are not very bright running them at constant 60mA.  The 60mA works good if I was investigating a closet. Most of my investigations are conducted indoors but some commercial buildings can be very large. The more distance I can cover within the invisible light spectrum the better.. I am also looking to cover the Ultra-Violet spectrum, But that will be for another day. Maybe this will help. http://www.liparanormalinvestigators.com/light.shtml (http://www.liparanormalinvestigators.com/light.shtml)

What is...boost SMPS.?
Title: Re: Paranormal Tools
Post by: kam on June 27, 2012, 23:09:30 PM
boost smps is a power supply topology which boosts the voltage from one level to a higher. So from 3 to 6 volts taken from your batteries you can boost it up to some 15-20 volts, with a constant current topology. So, regardless of your supply you will get fixed voltage.

Title: Re: Paranormal Tools
Post by: RealRiot on June 28, 2012, 12:39:45 PM
That sounds good, Are there any such circuits like that available.?
Title: Re: Paranormal Tools
Post by: kam on June 28, 2012, 16:36:04 PM
google and there are thousands. unfortunately i do not have one right now. i'm waiting a shipping from taiwan with some smps controllers...
Title: Re: Paranormal Tools
Post by: RealRiot on June 29, 2012, 00:28:32 AM
I have been checking online, I will continue checking this weekend for the switching mode power supply. I was glad to see not all require a transformer. That would add a significant amount of weight to my camera. There are quite a few that can be found of different input / output voltages. I have even come across one or two based around the 555.

The only thing I find to be questionable is the amount of electronics and the involvement in each of the circuits. We will see what I come across.

Just a thought :: It is my hope that other Paranormal investigators see this forum and become involved in conversation. Maybe one day if there are enough of us you may take into consideration creating circuits and tutorials based on the field of the paranormal. When getting involved in conversation Many will find it entertaining and educational. 

Most of the time when Paranormal investigators get together the forefront topic will always be related to circuits improving devices, Finding new ways and gadgets that may be helpful in the field.

I really have appreciated your taking the time and your assistance.  Thank you
Title: Re: Paranormal Tools
Post by: kam on June 29, 2012, 14:05:13 PM
my advice: do not work with the 555 for switching supply. There are chips dedicated for this, for all tastes.

The parts that you will need are more or less standard: a controller chip, an inductor, a diode, a switching transistor (some times if current permits this is included into the controller chip) and some smoothing capacitors....
Title: Re: Paranormal Tools
Post by: RealRiot on June 30, 2012, 07:12:02 AM
I have found two that appear to be well suited in accomplishing the task. I will begin testing when I receive the parts.
Title: Re: Paranormal Tools
Post by: kam on June 30, 2012, 08:07:43 AM
good luck! 8) 8)
Title: Re: Paranormal Tools
Post by: RealRiot on July 05, 2012, 03:06:23 AM
Looks like the SMPS circuits will not be suitable for my application.

They work opposite. Voltage should be stable and not regulated / Variable. What is needed is a stable Voltage output regardless of input voltage. Only current should be variable or fixed at the max current of 120mA or a little less.

A voltage regulator does change the voltage which in turn increases and decreases LED brightness. However, I was able to change or maximize the LED voltage to 1.7 volts and the LED did brighten. The current However did not change, Out of the 120mA max I was able to only get 70mA. Therefore the LED has still not reached it's potential for max brightness. Any more then 1.7 volts the LED would turn into a crispy critter.

In conclusion, I need a stable voltage output with ( variable current ) output. It is evident that just because I Max out the forward voltage that does not mean I am maximizing forward current.  :'(



 
Title: Re: Paranormal Tools
Post by: kam on July 05, 2012, 12:58:48 PM
Something that i think you confuse: Current through LEDs is the result of voltage. You cannot have voltage stable and regulate the current. The thing is that after a point, the current changes rapidly with a very slight voltage difference, and this may confuse you. That is because LED voltage to current characteristic is logarithmic.

What you need is an SMPS current source. This type of SMPS monitors the output current (and not voltage) and adjusts its voltage in a way that it provides stable current. Here is one example:

http://www.pcbheaven.com/userpages/high_efficiency_high_current_led_buck_driver (http://www.pcbheaven.com/userpages/high_efficiency_high_current_led_buck_driver)

This chip monitors the output current and changes the voltage accordingly, so that the current through the LED is around the selected area.
Title: Re: Paranormal Tools
Post by: RealRiot on July 06, 2012, 01:33:34 AM
Ok,
I think I understand.
I had decided to change some resister values and replaced them with variable. I think I may be on to something. May work after all. You have given me an additional thought as to the type of LED's I am using as well. I had watched your video and have taken notice of the LED that was used. So i started to look at 1 and 3w infrared Diodes  capable of 340mA and better. I think they will give me the advantage in distance i am looking for as well.

The only downside is that they consume more power. However, if a battery can last 4 to 5 hours I will be happy. Normally our investigations seldom last more then that.
Title: Re: Paranormal Tools
Post by: kam on July 07, 2012, 10:37:06 AM
3W LEDs are not that efficient compared to small LEDs. The higher the watts, the higher the temperature, and the higher the temperature the less the efficiency. But generally, they are good due to  their small size and ease of use. These LEDs require a good driver to drive them (constant current) if you want to get the most out of them. A small variation in voltage cause a large change in current.
If you drive them with constant voltage at maximum current, here is what might happen:  the temperature might increase and this will increase the current that might damage the led. So, if you do not drive the led with constant current, you need to keep the voltage a little bit lower than maximum, just for safety.


BTW: Do you have any video from these investigations? I'm so curious!
Title: Re: Paranormal Tools
Post by: RealRiot on July 08, 2012, 00:33:37 AM
 Here is a video of the most popular paranormal investigation team in the USA . This Video will also introduce some of the equipment that we use in our paranormal field ..  http://youtu.be/Mv6n91tDjC0 Remember all investigation are done in complete darkness.! They can only see using there infrared cameras and high power infrared lighting which can not be seen with the eye.

I have an investigation on Saturday. I will mention your name in the investigation. LOL You will see who I am and you will meet my team. I will also point out some of our equipment and how they are used. We anticipate the investigation to be very exciting.

Normally I would edit the video to only show evidence as it is caught because an investigation can last 6 hours or more. No one wants to watch 6 hours of video. I try to break it down to an hour or less. I may even have to break it down in parts each at one hour. We also use infrared security cameras in our investigations.