Ren's two transistor CFL circuit

[Drevtoobe]

Hey Lidmotor, that last clip you favourited, Mr. AllAmericanFiveRadio is great, and he is great. He has lots of clips on basic electronics that are really well done and I love his presentation.

A little trick is to do the same basic NPN setup with a 2N2222 but have 12 volts to a relay coil then to the transistor collector. Then just lick your finger tip and touch it across the collector and base leads and like magic the relay switches on. Current apmlification!!!!

[Lidmotor]

Mr AllAmerican's videos are very helpful. The one that I favorited really helped me understand the basic concept of how the little 2n2222 is doing what it is doing. It also reminded me NOT to leave a multi meter in a circuit because it has a power source and circuit values of it's own.

[Drevtoobe]

Yes indeed. When a multimeter is on ohms resistance measurement it is actually quite vulnerable. The only way to measure resistance is to pump juice through the resistance and measure the current flow, hence the battery inside the multimeter. If you accidentally have the multimeter set on resistance and put the leads across a battery to 'measure voltage', the battery can blow the multimeter.

[Drevtoobe]

Transistors are current-based animals. The main spec is the 'Hfe', which is the current amplification and is typically about 50.

If you put one unit of current into the base terminal, then 50 units of current flow into the collector terminal. Therefore, 51 units of current flow out of the emitter terminal. Note how when you cascade two transistors together in your circuit the current gain becomes 50 x 50. It's called a "darlington pair."

[Lidmotor]

Thank you once again. I am learning something new almost every day. A "darlington pair"---now I know what it is and what it does. 50x50 --- that explains alot and why the two transistors are paired the way they are in this circuit.

[armakuni2000]

Super discovery!!!! That spikes are exactly radiant spikes yahoo fantastic!!!

[Drevtoobe]

Just a general comment about the earth ground. Think of it like there is a giant conductive sheet of soil on top of the bedrock all over the planet. It is not a perfect conductor, it depends on the type of soil, the moisture content, thickness, etc. However, it is so large that we can look at it like a generic electrical ground. There may be some minuscule electrical noise and telluric currents in it, but it is not a source of electrical power in any way, shape, or form.

[Drevtoobe]

Hey Lidmotor, for what it's worth, on one of Aromaz' clips I offered up a theory as to why both the analog and digital meters will show zero. The digital meter is nothing more than a small computer sampling the current at regular intervals and running an algorithm to display the estimated value and has limitations. The bottom line is that you see the bulb get brighter, and more spike activity on the scope, hence the current consumption goes up.

[Drevtoobe]

With respect to the waveform it looks like the power transistor is switching on briefly forming a regular stream of spikes. Where is the probe connected in the circuit?

For all of these circuits where the earth ground is connected to the transistor base effectively what you are doing is making the 'microphone' more sensitive in the positive feedback circuit. This makes it easier for the circuit to go into spontaneous oscillation.

[Drevtoobe]

It's time for a big 'bubble burster' moment. There is no power coming up from the earth ground in all of the circuits that connect earth ground to the base. Like I said above, connecting the wire to the transistor base simply facilitates the spontaneous oscillation of the circuit. The battery pumps more power through the CFL load because the earth ground and associated wire 'tickle' the transistor base, allowing the battery to pump more energy. No power comes from the earth, period.

[dodoshlodo]

i understand that the Earth tickles the base, so are u saying that the Earth is like an antenna? if so wat is it recieving??

Also there IS power coming from the Ground, the early telegraph stations used an Earth battery to power them. Ive made an Earth battery that can light several LEDS. I've seen ppl make 12V earth batteries that can put iut 100mA...

[Drevtoobe]

No what I am saying is that there are two effects that promote the oscillation when you connect the earth ground to the transistor base. The wire itself will generate potential because of the small inductive coupling (transformer action) with the output side of the circuit. Secondly the earth ground connection will have some ambient electrical 'noise' associated with it that will promote starting the oscillation. The ground noise comes from a host of sources and is _extremely_ low in power.

[Drevtoobe]

Note that ALL electrical circuits have ultra-low-power electrical noise associated with them. Every resistor emits a white noise 'hiss' that is very hard to measure. It comes from the thermal energy inside the resistor causing random currents producing white noise. It all goes away at absolute zero, -273.15 C.

The power that you think is coming from the ground is actually pure chemical energy. The corroding dissimilar metals generate current, just like a lead-acid battery.

[Lidmotor]

I ran the experiment again yesterday using my little bank of super caps instead of a battery. I charged up the cap bank and timed the discharge while I watched the scope and looked at a volt meter showing zero amp draw. That was alot of fun. I got the system to slow blink at a very very low current draw. I bet you would have liked to have been waching over my shoulder when I did that one. The wave form had a tall spike with a squiggle at the end of it.

[Drevtoobe]

Very cool Lidmotor. I may have posted on one of your clips about how to measure unmeasurable pulsing DC where you use a big cap to simulate the batt. The trick is that while the big cap powers your circuit on the "out" side, you simultaneously trickle-charge the cap on the "in" side with an 18 or 24-volt batt source and a variable resistor. You tune the variable resistor to keep the batt voltage steady. Then measure the resistor value and the V difference and you have your real consumption!

[Drevtoobe]

The premise is simple: For the cap voltage to remain steady, by definition the smooth DC trickle charging current has to be equal to the unmeasurable pulsing current going into the load. It is very important to note that this also covers your bases if the load is reactive, i.e.; inductors and capacitors that may also push current back into the battery/cap.

Of course you could put your ammeter in series with the smooth trickle charging current also and watch the cap voltage with another meter.

[Can101276]

Hmmm... Seems to me the CFL must be lighting on the power of the collapsing electromagnetic coils. Isint this basicly like Imhotep's relay charger, rapid oscilation of the coil and capture the back EMF??

[dodoshlodo]

well the cfl is being lit by the HV side (secondary winding) of the ignition coil. u can catch the back emf off the primary winding by using a diode on the -ve side and dump it into a secondary battery... You're right, its very much like the Imhotep design, only without a relay.

I've found however that the back EMF contributes to more significant charging with a relay, or if u introduce a spark gap. As many of us have learnt with the Bedini motors, there is something about the spark that helps

[Can101276]

Ahh yes... allowing the conventional current to momentarily pause and jump the gap, allows the radient or negative energy to essentially build up in the area of the spark gap. Seems that even when it comes to electricity the universe seeks ballance.

[dodoshlodo]

thanx, that would make sense, I was measuring the back emf coming off the battery the other day, and blew my multimeter when i introduced a spark gap

[marthale7]

You might use the scope to monitor voltage useage. Interesting... I wonder if you have reached the limits of the digital meter. I guess the real test is to measure battery loss... maybee fill some of your super caps and see what time period it takes to empty them..

[Lidmotor]

OK Mart --Sounds like a good idea. Stick a mean ole cap on it and just see how it likes THAT!! I bet it runs down in less than a minute. Those darn lying meters!!! Still-- that is the first time I have seen all zeros on a meter and the device was still running.

[dodoshlodo]

hey lidmotor, i made something simlar the other week. the base isn't hooked up to nothing, the circuit is being oscillated by the ground.

watch my video, i show how to make a brighter light, try connecting the other side of the cfls through a cap to the base of the transistor once u have got it started with the Earth wire:

watch?v=wXKR7rJdze8

[Lidmotor]

Wow dodoshlodo---Great video!! Everyone who wants to build one of these should watch it. I will try the capacitor in the CFL return line to the base. That is a terrific idea. I agree 100% with your dicription of what is happening here.

[dodoshlodo]

cheers lidmotor, much of the inspriration came from watching your videos, so thanks!

with just the Earth to the base, obviously its not pulling much voltage, and low light.

The cap seems to store up energy from the HV (cfl) line and effectively turns on the transistor fully, so naturally we will see more light but more current draw

I would be interested to see u do this with a rheostat to limit the current draw - I dont have one yet so i cant test it..

[dodoshlodo]

make sure the cap is electrolytic, i have tried different caps, & a higher value seems to work better (47uF). I think the cap charges and dumps its load into the base, giving it a better oscillating effect

[Inquorate]

sweet scope lidmotor - try a glass of salt water with a crystal in it,s see if has same effect as your touch :-)

[Lidmotor]

Inquotate--Does it matter what kind of crystal? About the only crystal around my house sits on my wife's finger and I don't think that she will let me borrow it.

lol

[Drevtoobe]

The glass of salt water with the crystal in it would be nothing more than a demonstration of the capacitive coupling effects that have already been discussed before. Putting just about any object next to a CFL creates a stray capacitor to ground between the CFL glass tube and the object. The high-frequency AC potential current 'leaks' through this stray capacitor and the CFL gets brighter as a result.

[eroutt]

place a coil on top of the cfl! sounds crazy right? try it.

[Lidmotor]

eroutt-- I have already tried that and in fact a few months ago Bodkins and I were using a coil of wire around the bulb to charge up a cap. There is alot of energy escaping through the glass.

[eroutt]

i plugged the cfl to my bedini solid state, and it light up but not to full brightness! i left the circuit, and i also added a 100v cap across the 5k pot. weird but it works! not sure how? but it does! i will post a video of what i have so far. nice work lidmotor!