Home     Forum     Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science

### Author Topic: Paranormal Tools  (Read 7996 times)

0 Members and 1 Guest are viewing this topic.

#### kam

• Hero Member
• Posts: 1849
##### Re: Paranormal Tools
« Reply #15 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

This chip monitors the output current and changes the voltage accordingly, so that the current through the LED is around the selected area.

#### RealRiot

• Guest
##### Re: Paranormal Tools
« Reply #16 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.

#### kam

• Hero Member
• Posts: 1849
##### Re: Paranormal Tools
« Reply #17 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!
« Last Edit: July 07, 2012, 10:44:42 AM by kam »

#### RealRiot

• Guest
##### Re: Paranormal Tools
« Reply #18 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.
« Last Edit: July 08, 2012, 02:20:58 AM by RealRiot »