Testing the TK Tar Baby

[TinselKoala]

Well, I made another transmitter loop that is 2 inches longer. This helped I think. It goes into the "brilliant" mode more easily, stays in with the receiver farther out, and lowered the "nonbrilliant" frequency to under 1 MHz. The "Brilliant" frequency is close to 812.5 kHz and when the transition occurs it is not nearly as noticeable as before, I guess because the freq change isn't as great.

The glass in the bulb is darkening a lot; I almost can't see the filament when it's off. I think this is strange; I have another bulb of the same type.. but sheesh, have you priced small auto bulbs lately? They are all packaged 2 to a blisterpack now, and all cost about 5 dollars the package, no matter the bulb type. It is outrageous to pay 2.50 for a 161 when an 1157 costs the same but has ten times the tungsten and brass and glass in it.

[Magluvin]

Well, I made another transmitter loop that is 2 inches longer. This helped I think. It goes into the "brilliant" mode more easily, stays in with the receiver farther out, and lowered the "nonbrilliant" frequency to under 1 MHz. The "Brilliant" frequency is close to 812.5 kHz and when the transition occurs it is not nearly as noticeable as before, I guess because the freq change isn't as great.

The glass in the bulb is darkening a lot; I almost can't see the filament when it's off. I think this is strange; I have another bulb of the same type.. but sheesh, have you priced small auto bulbs lately? They are all packaged 2 to a blisterpack now, and all cost about 5 dollars the package, no matter the bulb type. It is outrageous to pay 2.50 for a 161 when an 1157 costs the same but has ten times the tungsten and brass and glass in it.

Very good.  Still might need fine 2ning. ;] 

The blackening of the glass is just from overpowering the bulb. Step up to the higher wattage, for the same price.    Ya get 2 filaments in some. Pk light and brake.

Here is a number request.     What power can the Tx handle? At 12v?

Mags

[TinselKoala]

What power can it handle...
Well, I dunno. The mosfets are IRF44Z and I haven't blown one yet. They don't even heat up appreciably, although at  max power they do warm a bit. The capacitors in the receiver seem to get quite hot; I think it's the caps and not just heating from being close to the bulb. I'll try different types of caps here; these should be poly but maybe I got the wrong type.

Right now with the new xmtr loop it's drawing about 2.2 amps from the 12 volt battery at the brightest and I can get at least 4 times farther away before it cuts back to the higher freq. And there isn't much brightness change at that point. When I first turn it on it "defaults" to the brilliant mode if the receiver is anywhere reasonably close but will flip to the now slightly higher less brilliant mode when I start moving further away.

So I think if I add maybe another half an inch to the coil to bring the freq down a bit more, I'll be there. Or perhaps take a bit off the receiver coil.

[Magluvin]

Very cool.  Does it still increase input the further away as before?

Is the light not quite super nova now? 

Thanks for building that. ;]

Mags

[TinselKoala]

I've changed the caps in the receiver and found a combination that gives even brighter light, and less heating in the caps. I think my first set have actually failed; when they get really hot the light gets into a dim mode and the full mutual resonance is lost. So I am now experimenting with receiver caps to try to find a combo that will give me 60 nF plus or minus one or two nF, rated at least 250 V and don't heat up so much. And are small... I could put another 6 of the same rolled caps that are in the transmitter but that doesn't seem elegant, somehow.