Simple 8 and 1 LED project help

Discussion in 'General Electronics Chat' started by rkdmm, Apr 3, 2014.

  1. rkdmm

    Thread Starter New Member

    Apr 3, 2014
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    Help please. I would like to build a 8 LED and a single LED efficient circuit using a 12V supply. The LED's would consistently be in the on position and supply would have a charger on at all times (if that makes any difference to the circuit). This circuit has to have an ORP12 or something similar in it to trigger a 12V pulse with the ability to control the pulse from 30 to 100 times per second. The more I research what I want the more confused I become as I know Very little about Electronics but do know there is some very smart people out there that could do this in there sleep. If you know what your doing this circuit should be very simple even for me to build. Note..a schematic with R1 R2 etc. does me no good. Showing what it is, its name,values (resistor-orange,blue, brown,gold) etc. would REALLY help. At one point I though that running the LED's in parallel opposed to series would be more efficient, now I no longer know. Yes it's like leading a child by the hand but could someone PLEASE help me. Tks in advance for your efforts. they are very much appreciated.
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    The Completed Projects Forum is for Completed Projects only. It is meant to allow members to show plans for projects they built so other members can duplicate them if desired. New threads are also automatically moderated per Moderator review for this reason. Your thread does not belong in this forum, and was moved here.
     
  3. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    What is ORP12?

    with the ability to control the pulse from 30 to 100 times per second
    Pulse of what length?
     
  4. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
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    Welcome to AAC.

    We're happy to help, but you're going to have to provide a lot more details.

    So far, I've caught:
    • 8 LEDs
    • 1 LED
    • 12V Power
    • Charger
    • ORP12 - LDR (light-dependent resistor)
    • 30-100 Pulses

    Are the eight LEDs and single LED controlled by the same circuit of are they controlled separately?

    You mention 12V, is this the power supply? Is it AC or DC? If unsure, post a picture of it with any labels clearly shown.

    What is this mention of a charger? Is this connected to a battery? Is the charger always connected to the battery? Is the battery connected to or powering anything else?

    You mentioned an ORP12 - a quick Google search turned up a light dependent resistor (LDR). Are you wanting the pulses controlled by the LDR? If so, how?

    What is the purpose of the pulses? To flash the LEDs or simply control their brightness? If there is more light do you want the pulses to increase or decrease?

    If you could describe in detail what it is you are trying to do, we can better help. Don't worry about using electronic lingo, pretend we're third graders and tell us in simple terms, step-by-step, what it is you want the circuit to do. We'll ask more questions if needed. ;)
     
  5. rkdmm

    Thread Starter New Member

    Apr 3, 2014
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    Tks. for reply. Ill do my best but grade 3 might be a little high. For all intense and purpose I think it would or could be called a "loop charger light"!?! The power supply is a12V, 3Ah battery. I want to make a break beam circuit using bright white LED's and LDR's to send a 12V pulse to 8 12V coils (0.2 A each or 1.6 A total). The coil pulse would turn a rotor that has 8 segments to it so the ciols would have to pluse 8 times for 1 revolution. To achieve 2000 rpm. all 8 coils would have to pulse 266 times per second. In return ( putting it simply)a second rotor would turn at the same rate supplying current to a second set of larger coils that would feed a AC current to a bridge rectifier supplying a 14-15V to the battery. Kind of a closed circuit to keep the battery charged. I would like to use this set up if possible as the 8 LED's would serve two porpoises, 1 it would keep a light on in the cabbin (even during those All to often winter cloudy days where solar fails) and 2, keep the battery charged that runs them. I have not figured out the charging circuit yet (1 problem at a time) but have the got the 8 coils working. The problem now is to build a trigger of sorts that can pulse the coils at a rate of 266 pules per sec. At first I though that a proximity switch would be best to use as a trigger and run the LED's of the battery, but then, why can I not use the LED's in a break beam configuration and kill two birds with one stone, or am I beyond mental help? Don't feel bad with a "YES" reply but I think it should work, at least in my mind.
     
  6. rkdmm

    Thread Starter New Member

    Apr 3, 2014
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    Having two or more batteries is too simple.. this project keeps me from looking at the wife's car, the sleds etc. After all..happy wife, happy life.
     
  7. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    I'm still not quite sure I follow but let's see . . .

    1. You have a battery or set of batteries normally charged with solar cells.
    2. You want to connect the batteries to a set of LEDs.
    3. The LEDs will be pointed to LDRs which are connected ultimately to eight coils that turn a motor.
    4. The motor is connected to a generator.
    5. The generator spins providing power to a charger connected to the battery.

    Is this correct?

    Unfortunately, what you're describing, again assuming I understand correctly, is a perpetual motion or over-unity device. This won't work. You have to provide energy from the battery in order to turn the motor and ultimately the generator and you'll always put in more energy than you'll get out due to efficiency losses. For example, if your motor requires 5 watts to run, the generator will always produce less than 5 watts, so you're always losing energy from your battery rather than retaining it.

    If the battery's only purpose is to drive lights, your best bet is to pick lights (LEDs being a great choice) that require the least amount of power for the amount of light you need. This will allow the battery to last the longest between (solar) charges.
     
  8. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    783
    The ORP12 is a cadmium-sulphide photo conductive cell, or LDR (light dependant resistor).

    Lately I've noticed a few suppliers have dropped them and they don't feature as frequently as they used to in magazine projects - I'm wondering what is their current RoHS status.

    The LDR has a pretty slow response - for anything needing a quick response, its better to use a photo-diode and op-amp voltage follower.

    A photo transistor is more sensitive than the diode, but is slower - not as slow as the LDR though.
     
  9. rkdmm

    Thread Starter New Member

    Apr 3, 2014
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    Went on line - checked for over-unity. Your right, most of those sites smell funny. As for the pulse length, it would be controlled mechanically (via a simple multiple layered adjustable disc for duration and timing) the LED's would be on continuously. The disc would both allow and break the beam to the photo cell thus allowing it to energize and degrade, its 100% adjustable, reliable and uses no energy.
     
  10. rkdmm

    Thread Starter New Member

    Apr 3, 2014
    5
    0
    As for the 12V LED I just found out you can buy a single 12V LED that simply wires directly to source. That small piece solved. As for over-unity..well I guess its back to batteries, but, since equipment and mechanics is no longer an option (work, faulty jack-stand, tipped over track machine, broken back, time off) and I have started down this road of futility it does give me structure. At least I know where I'll end up. At worst I can finish this small project and ask myself, "Why did you stop there. Is this the best you can do?." As you allready know where this project will end up a no reply will be accepted gracfully and I Thank-You for your time and knowledge. Necessity is the mother of invention. One does have to think out side of the box, but first I have to find the box so I can think out side of it. Photo-diode. Excellent ! Be well.
     
  11. wayneh

    Expert

    Sep 9, 2010
    12,113
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    Not sure what you mean by this, but for sure it is not capable of perpetual motion. Nothing is. Bearing friction, air resistance, etc.
     
  12. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
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    I'm still not clear on how you're envisioning the system, but I didn't go into details that perhaps would help.

    The LDR will not produce power. It will simply increase or decrease resistance. If you were planning to control a motor-generator set of sorts, you could use the LDR to control a transistor which would control the motor (PWM or otherwise). However, the motor needs power to run and this would come from your battery, not the LDR. Hence, you'd be using battery power to supply battery power. As Wayneh mentioned, efficiency losses due to mechanical resistance and changing energy from one form to another (electrical to mechanical back to electrical) dictate you will always consume more power than you generate. If you were to somehow obtain zero losses, the best you could hope for is to come out even, example: using one watt of power to generate one watt of power. However, this gains you nothing, so there would be no point in adding such a system.

    You don't have to take our word for it though, you can prove this to yourself. Power your motor-generator set and add some load, say a light bulb. Measure the voltage on the input and output, then do the same for the current. Now multiply the incoming voltage and current, then multiply the outgoing voltage and current. Assuming everything is DC power, you now have the incoming and outgoing power in watts. The incoming power will always be greater than the outgoing power.

    If your ultimate goal is to give yourself something to do and increase the battery life on overcast days, there are other options you could explore - look for other power sources or increase the battery run time by decreasing the power drawn by your load. Some examples of the former are spinning a generator using a nearby creek, wind turbine, indoor solar cells to recycle some of the light, etc. These are not without their limitations or difficulties, but they are some other avenues to explore.
     
  13. wayneh

    Expert

    Sep 9, 2010
    12,113
    3,039
    Yes please give up now on any perpetual motion or over-unity project. They are not worth your time. Re-inventing the wheel would at least leave you with a wheel, something that works. At best the perpetual motion projects are a learning experience, but a quick read of a physics book would give you a much better education.

    There are many project ideas that might interest you, and result in useful items. Just let folks here know what tickles your fancy.
     
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