The lightbulbs represent a 20ohm load. I think that a reasonably sized Power resistor would work here, but this amp has nothin to do with this thread. If Nelson would give it a pet name for now, such as School Boy amp, then we could get started, or maybe Depletion mode Mosfet amp. Guess that wood work.
Time for me to read the review of the real J2...
Time for me to read the review of the real J2...
What a crap! Let's all get eyes disturb with those horrible energy-saving fluorescent lamp 🙁
What about instead of using a light bulb using a few tubes instead just using the
heaters for the load resistor. Kind of a passive hybrid.
heaters for the load resistor. Kind of a passive hybrid.
Well, for the Diy'ers in countries with the green light bulb problem, you can also use water heater elements. 
In the US I tried a few and I think I scrounged up some 4500W units that are about right. 4500W/220VAC 10ohms(they were actually slightly lower) but you have to watch out for the temp they get to in the open air. They come in several shapes and sizes.
There is a version of Zen Light on this forum somewhere built exactly that way. You don't get any of the warm glow though🙁
In the US I tried a few and I think I scrounged up some 4500W units that are about right. 4500W/220VAC 10ohms(they were actually slightly lower) but you have to watch out for the temp they get to in the open air. They come in several shapes and sizes.There is a version of Zen Light on this forum somewhere built exactly that way. You don't get any of the warm glow though🙁
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There are still alternatives, for example this 105W halogen light bulb. Take a look here:
Halogenglühlampe klar
I think, they are beautiful! 🙂 Manufactum says, that their phase out date is september 2016. 🙂
The water heater element idea is brilliant too! Think of an amp with included coffee/grog/glogg warmer! 😀 OK, liquids and electricity do not go together well...
Halogenglühlampe klar
I think, they are beautiful! 🙂 Manufactum says, that their phase out date is september 2016. 🙂
The water heater element idea is brilliant too! Think of an amp with included coffee/grog/glogg warmer! 😀 OK, liquids and electricity do not go together well...
Attachments
halogen sticks , also heating elements of so called "Quartz" stoves ; in fact plain resistive spiral , put in quartz glass tube
Well, for the Diy'ers in countries with the green light bulb problem, you can also use water heater elements.
We can eventually organize a GB from a big electric appliance shop in US that our friends overseas will suggest togheter with the right codes for some suitable bulbs and sockets.....
It shouldn't be illegal to import in Europe some 120 V bulbs as hard to find spare parts.
Yes! We can buy a nice kettle in UK where they are very popular and easy to find (not in Italy) and prepare a good tea (my favourite is Assam) while listening to music.
How 'bout the deLite ? (Maybe someone would come up with a deLite deLuxe after that...)
Yes! We can buy a nice kettle in UK where they are very popular and easy to find (not in Italy) and prepare a good tea (my favourite is Assam) while listening to music.
Just buy the replacement element!
Are light bulbs considered a really good choice for a current source? I see them used in quite a few designs and liked the simplicity and low cost.
Could they also be used in a CRC power supply to help with the ripple in place of an expensive power resistor?
Tad
Could they also be used in a CRC power supply to help with the ripple in place of an expensive power resistor?
Tad
An active CCS will be better than a light bulb but as you said they are simple,low cost,
don't need heatsinks and as I think Nelson said " they look neet" In the F5 power supply
Nelson uses 4 3w .47ohm resistors in parallel for the r in his CRC filter these can be
bought for 47c or less. In this case the resistance of a light bulb is much to high unless
you wanted to parallel over 100 of them!
don't need heatsinks and as I think Nelson said " they look neet" In the F5 power supply
Nelson uses 4 3w .47ohm resistors in parallel for the r in his CRC filter these can be
bought for 47c or less. In this case the resistance of a light bulb is much to high unless
you wanted to parallel over 100 of them!
For lower voltage/less R you can use auto bulbs particularly brake light bulbs. Inexpensive and only a few ohms. Maybe you'll need to paralell a few
I keep Replying but this is the J2 thread, Sorry.
I keep Replying but this is the J2 thread, Sorry.
Some years ago when N.P. came out with Zen Lite I went to the store and bought a couple handfulls of everything they had. I went home and plugged 'em into my DC Pwr Supply and measured 'em. I have posted a graph or two of the results here before but, suffice it to say, in a static DC condition they would be resonable. But, on a V vs I graph they all showed nonlinearity. That is, a curve, vs. a resistor being a strait line. Keep in mind this is steady state, allowing any dynamic variation to stabilize.
The next step would be to do real dynamic testing. For instance running the power supply through a big switch being driven by a square wave? Or maybe a sine wave and measureing resultant THD?
For those who have read the latest article regarding distortion cancelation the curve might be usefull??? Something tells me though the dynamic response will probably look more like an huge inductor and not usefull in the audio range??? with music as a source it might even float around with the average level 😕
BTW, The water heater elements were purely resistive under the static conditions producing a stait line on the V vs. I graph
So, why dont we start a depletion Zen Light thread or whatever N.P. wants to call it???
Some years ago when N.P. came out with Zen Lite I went to the store and bought a couple handfulls of everything they had. I went home and plugged 'em into my DC Pwr Supply and measured 'em. I have posted a graph or two of the results here before but, suffice it to say, in a static DC condition they would be resonable. But, on a V vs I graph they all showed nonlinearity. That is, a curve, vs. a resistor being a strait line. Keep in mind this is steady state, allowing any dynamic variation to stabilize.
The next step would be to do real dynamic testing. For instance running the power supply through a big switch being driven by a square wave? Or maybe a sine wave and measureing resultant THD?
For those who have read the latest article regarding distortion cancelation the curve might be usefull??? Something tells me though the dynamic response will probably look more like an huge inductor and not usefull in the audio range??? with music as a source it might even float around with the average level 😕
BTW, The water heater elements were purely resistive under the static conditions producing a stait line on the V vs. I graph
So, why dont we start a depletion Zen Light thread or whatever N.P. wants to call it???
FLG,
I opened a group buy thread for the FET at least, feel free to discuss amp and willingness to put the money on the table there. This will give papa some time to work on details, and stop polluting this thread.😛
http://www.diyaudio.com/forums/grou...letion-mode-mosfet-group-buy.html#post1957478