# Circuits 4 U

453

7

BOY HOW, I do hate to loose a couple paragraphs of text while eating supper with the family...

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To Begin Again;

This circuit will deliver a fixed current to any RGB color LED at any voltage from 6V DC, to 9V, to 12V up to 35V with Heat Sinks..

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To Explain;

Look at the 3 pin LM317's being used as constant current regulators with the same single resistor for every color and any voltage 6 to 35 Volts.

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For the the beginner;

LED current comes into the (IN) pin and out the (OUT) pin, when the voltage across the resistor equals 1.25v

I = voltage / resistance = 1.25 / 4.2 = 297.6 ma.... As sensed by the (ADJ) pin the LM317 holds the output current to 0.2976 amps by regulating voltage.

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Change the Resistor changes the current !

If you use a 61.9 ohm 1% resistor the LED control current will be 20.2 ma irregardless of any LED forward color voltage drop or supply voltage..

The reason you need heat sinks to dissipate excess heat as the supply voltage increases is that the LM317 acts like a power resistor..

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Final Super LM317 Safeguard;

The Only electrical parameter that may damage the LM317 is a voltage in excess of 35 V DC.. So for safety sake stay below 33VDC.. Even overheating the unit will just make it go into self shut down and when it cools it will restart until overheat then shut down then cool and make a dandy thermal oscillator ;-)

GO TO STEP_2

### Teacher Notes

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## Step 1: SMALL BATTERY SHAPES

Here are some interesting shapes of small batteries made of Lithium and alkaline chemistries..
They are various height and differing diameter Cylindrical Cells.. And a large Lithium DR2450 / CR2450 Button Cell.. Then we see a Mini Cell battery holder and some perforated fiber board battery clips that work well for cylinder batteries..

Finally we see a guts disassembly of a 9V Lipo battery.

## Step 2: PCB Assembly

This is a two sided printed circuit layout 5.075" wide by 3.000" high..
Red traces represent the traditional Component side and the circuit. Blue traces represent the Solder side where the RGB LED is the only component on the back side.

## Step 3: Gerber Files

The Gerber files are free to use.

A definition of extensions

• BOT = Bottom traces
• BSM = Bottom Solder Mask
• BSS = Bottom Silk Screen
• DIM = Dimension
• DRL = Drill
• SYM = Symbols
• LST = List
• TOP = Top traces
• TSM = Top Solder Mask
• TSS = Top Silk Screen

## Step 4: PICTURES FOR QUESTION

This is a water bottle.

Please note the 2D code sequence circled in red that may be sequential..

## Step 5: STEAM BOILER

Doble made the simplest steam car because he allowed some steam to escape vs Lear's closed system steam bus where all the expended steam Had to be recondensed.

At one time the Doble it was housed in the Harrah's Reno car museum, ruthlessly divid up by greedy collectors in the late 1900 !

Obviously with wood you will need to fire from below.. Soot buildup will be a problem forever insulating the water from a fire..

## Step 6: Low Cost Non-Cu Wire

JOANN Fabric and Craft Store sell gold and silver spools of easily solderable wire.

Note silver and gold 20,24,28,32 gauge a lot cheaper then bell wire, bare or tinned copper wire..

Also some copper magnet winding wire and a, rare for me, iron coated wire that can latch to a magnet !

Granted craft wire has a larger resistance but that rarely affects the average circuit function..

## Step 7:

First make the 3way toggle switches work !

A 4way version is shown only for reference :-)

Then with a proper 3-Way motion switches in place of the toggles it should work !!

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If you do not have Proper 3way motion switches, then two 120VAC relays must be used, one in place of each lamp..

Then the Normal_Open contacts are wired in parallel as one contact and that is placed in a normal lamp and switch.to an AC power line :-)

Participated in the
Epilog Challenge 9

## Recommendations

• ### Large Motors Class

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