God Bless,
Dave
:I would purchase the power supply kit from AES and build it. I use one and u should get any voltage for any battery radio God Bless America
http://www.tubesandmore.com/
AKA Antique Electronic Supply in Arizona. Page 103 of current catalog; $53.95. I didn't want to get in ahead of Stewart but I wanted to give you my thoughts. I have this power supply and use it ever so often. However it does not always physically fit for use. So I'm thinking about building my own. Have built in the past and modified other ones, got rid of them, etc. My thinking today is if one with a battery set don't want the batteries...well just build a power supply specifically for each set. Norm has offered up some. Another source is jump over to Antique Radio Forum site and find the thread on power supplies. I'm sure Norm had input in that one too. I haven't decided which one I'm going with or when I will. But I have been collecting various parts as I run into them.
Bill VA
:Stewart: please be more specific on the source for power supply kit. Does it have multiple taps for the varioous voltages required. Than you
:
:God Bless,
:
:Dave
:
::I would purchase the power supply kit from AES and build it. I use one and u should get any voltage for any battery radio God Bless America
I have simplified the K=101A's B+ ckt and the whole shebang could fit on a smaller printed ckt board (rather than the wooden breadboard that comes with the kit): http://www.enginova.com/batt_elim.htm
Also, the K-101A's C- supply could be eliminated altogether and just use a lithium battery for the bias (if required for a particular radio). The xfmr could then be replaced with just a little 24-volt (or so), CT, single secondary, for the AC supply to the diode bridge for the filament supply.
I also have an ARBE-III battery eliminator, which I use for a bench supply. But that is a little too expensive to use as a dedicated supply for individual radios.
Doug
:Dave, he's speaking of the power supply kit, K-101A you can find on this site:
:
:http://www.tubesandmore.com/
:
:AKA Antique Electronic Supply in Arizona. Page 103 of current catalog; $53.95. I didn't want to get in ahead of Stewart but I wanted to give you my thoughts. I have this power supply and use it ever so often. However it does not always physically fit for use. So I'm thinking about building my own. Have built in the past and modified other ones, got rid of them, etc. My thinking today is if one with a battery set don't want the batteries...well just build a power supply specifically for each set. Norm has offered up some. Another source is jump over to Antique Radio Forum site and find the thread on power supplies. I'm sure Norm had input in that one too. I haven't decided which one I'm going with or when I will. But I have been collecting various parts as I run into them.
:
:Bill VA
::Stewart: please be more specific on the source for power supply kit. Does it have multiple taps for the varioous voltages required. Than you
::
::God Bless,
::
::Dave
::
:::I would purchase the power supply kit from AES and build it. I use one and u should get any voltage for any battery radio God Bless America
Well, in my electronics class lately we're studying diodes and transistors.....and the thought just hit me while we were studying voltage regulators. I -could- parallel a few voltage regulators if each had its own adjustment circuit, AND if the output of each was then fed through a diode. The diodes would allow current flow out of each regulator circuit, but current from one regulator couldn't flow into another regulator circuit. Each regulator would regulate on its own.
I will have to give it a try. It sounds like it has a lot of hope. That project is on my back burner for now.
T.
Back in the early 80's I think I toyed with with using a TO-3 power transistor (2N3055 probably) with it's base fed from the LM317 output to get a heftier variable bench supply. As I recall it worked pretty well. You may want to try that as an alternate to multiple 317s.
TonyJ
:...Speaking of battery eliminators...... do any of you remember back a long time ago when I was trying to build an A eliminator for a Radiola 16, and had trouble with the LM317 regulator overheating? If I'd connect several in parallel, they'd oscillate back and forth, and one or more would still get hot.
:
:Well, in my electronics class lately we're studying diodes and transistors.....and the thought just hit me while we were studying voltage regulators. I -could- parallel a few voltage regulators if each had its own adjustment circuit, AND if the output of each was then fed through a diode. The diodes would allow current flow out of each regulator circuit, but current from one regulator couldn't flow into another regulator circuit. Each regulator would regulate on its own.
:
:I will have to give it a try. It sounds like it has a lot of hope. That project is on my back burner for now.
:
:T.
:
:Back in the early 80's I think I toyed with with using a TO-3 power transistor (2N3055 probably) with it's base fed from the LM317 output to get a heftier variable bench supply. As I recall it worked pretty well. You may want to try that as an alternate to multiple 317s.
:
:TonyJ
:
:
::...Speaking of battery eliminators...... do any of you remember back a long time ago when I was trying to build an A eliminator for a Radiola 16, and had trouble with the LM317 regulator overheating? If I'd connect several in parallel, they'd oscillate back and forth, and one or more would still get hot.
::
::Well, in my electronics class lately we're studying diodes and transistors.....and the thought just hit me while we were studying voltage regulators. I -could- parallel a few voltage regulators if each had its own adjustment circuit, AND if the output of each was then fed through a diode. The diodes would allow current flow out of each regulator circuit, but current from one regulator couldn't flow into another regulator circuit. Each regulator would regulate on its own.
::
::I will have to give it a try. It sounds like it has a lot of hope. That project is on my back burner for now.
::
::T.
Hi Tony and Thomas,
I think Tony has the better method, one I have commonly seen emplyed. The problem with using multiple LM317, aside from complexity, is that at least one will need to be loaded out of regulation for any of the others to chip in.
Keep it up Thomas, creativity is good!
Bst Regards,
Bill Grimm
::
::Back in the early 80's I think I toyed with with using a TO-3 power transistor (2N3055 probably) with it's base fed from the LM317 output to get a heftier variable bench supply. As I recall it worked pretty well. You may want to try that as an alternate to multiple 317s.
::
::TonyJ
::
::
:::...Speaking of battery eliminators...... do any of you remember back a long time ago when I was trying to build an A eliminator for a Radiola 16, and had trouble with the LM317 regulator overheating? If I'd connect several in parallel, they'd oscillate back and forth, and one or more would still get hot.
:::
:::Well, in my electronics class lately we're studying diodes and transistors.....and the thought just hit me while we were studying voltage regulators. I -could- parallel a few voltage regulators if each had its own adjustment circuit, AND if the output of each was then fed through a diode. The diodes would allow current flow out of each regulator circuit, but current from one regulator couldn't flow into another regulator circuit. Each regulator would regulate on its own.
:::
:::I will have to give it a try. It sounds like it has a lot of hope. That project is on my back burner for now.
:::
:::T.
:
:Hi Tony and Thomas,
: I think Tony has the better method, one I have commonly seen emplyed. The problem with using multiple LM317, aside from complexity, is that at least one will need to be loaded out of regulation for any of the others to chip in.
: Keep it up Thomas, creativity is good!
:
:Bst Regards,
:
:Bill Grimm
If you really need to provide some current you can use a power darlington transistor.
Radiodoc
**********
The reason why I want to stick to LM317s is because they are readily available at my local Radio Shack. I already ordered a 3 ampere version, and it wasn't that impressive. It eventually got too hot, and then regulated itself off. I like to be able to purchase the parts locally, without the wait and shipping charges.
I originally wanted to build a power supply that would fit below the Radiola 16 chassis, and I still may, but now I'm thinking more towards an external supply, especially since I now own a Majestic B eliminator. If I build an external supply, of course I can use lots of heat sinking. My problem was getting results in the compact space under the Radiola 16 chassis.
T.
Hmmmm...it would be a rarity if I even showed very much interest in a battery powered set...but I guess there are a few that have interest in them.
Tomas....In your situation of the regulated power supply...I have been building them since the '60s with just a handfull of discrete xtrs feeding into a series pass xstr along with a zener diode for referencing against.
No sense in shelling out the big bux for a kit when one can be built for dollars instead...with ones electrical / electronics and mechanical expertise...with a transformer available, it is dirt cheeeep and I happen to have ~ 50 applicable power T-formers in my well stocked junque box.
In the late 60's the LM105...the grandfather of the of LM30XX...series was introduced, but on it, you had to provide the power pass xstr adjunct to it. Also, the LM 723 was coming online at about the same time, with the same situation of the pairing of it with a companion power xstr. With the final blending of both the precision reguator with the power aspect thay had the LM305-9-12-15-24 and finally the 317 as their adjustable rather than fixed voltage output version. With that unit, they had it all covered up to the 37V upper voltage limit and the 1.2 V lower adjustment.
Those units having thermal protection, overload protection and VERY good loaded / unloaded performance.
Your shortcoming on the current requirement that you were / are experiencing was covered from day one in their application notes. It was just a matter of inserting a low value resisance in the power feed line to the regulator and then you come in and insert an PNP power transistors base emitter junction across it to sample the current pull. The power transistor will be tracking the current changes with its sampling and ends up handling about 70% of the power handled while the '317 loafs at about 30% of the power, yet you still retain all of the additional features of the IC. On the mark-up schema the blue path is the conventional 317 power path, while the red path is that of the power transistor.
There is a markup of that circuitry below, in which case the circuit will get you upwards of 4 amps out from it or parallel another PNP power pass above it with its own .3ohm emitter balancing resistor and double that available max current again.
Heatsinking is a matter of the power pulled thru it, if one is up in the amps thats important on the power xstr heatsinking, whereas the reduced strain now imparted on the '317 is such that it only neeeds minimal heatsinking.
The referencing to the input filtering capacitance is also dependent on the application, if used for some heavy filament consumption, filtering would be of less import and that number could drop down to the 470 ufd range. Don't mess with the low output filtering capacitance as it is of a low value to speed up corrective response of the IC's internal compensatory circuitry.
Another consideration is the difference in the raw DC input voltage versus the voltage one ends up setting the output to. IF one had a 2V- 6V tube(s) pulling upwards of an amp, about 12 watts of power would end up being dissipated by the power pass transistor....wasteful.. and a bit hot also .
The shown circuit would take care of most filament supplies on up into the amps, but for getting the common 45 - 67 1/2 - 90 - 105 .....(or any adjustment between)....battery B+ supply voltages in the decades of milliamperes...max..... for plate and screen supplies, one only needs to utilize the variant of the circuit that lets one get all of the same quality regulation features. In that approach, one goes to the floating technique as is shown in this reference, where, even in using it, the same shunting can be utilized to bring up the ~40 ma output of that circuit...however I think that is probably enough for battery sets that I have seen. In that case the TO-3 casing of the 2N2955 (which CAN'T handle this higher voltage)could use a smaller HV rated transistor of the TO-66 or plastic TO-220 serving fine .
Hot link to the isolated circuit for use of the LM317 in its producing on upwards of 160 VDC at 25 ma
[ http://www.national.com/an/LB/LB-47.pdf ]
73's de Edd
:Well, the thing is that if each output was fed through a diode, none could feed back on the others, so it wouldn't matter what each one was putting out (if one was putting out a bit more than another). No one regulator could trigger another.
:
:The reason why I want to stick to LM317s is because they are readily available at my local Radio Shack. I already ordered a 3 ampere version, and it wasn't that impressive. It eventually got too hot, and then regulated itself off. I like to be able to purchase the parts locally, without the wait and shipping charges.
:
:I originally wanted to build a power supply that would fit below the Radiola 16 chassis, and I still may, but now I'm thinking more towards an external supply, especially since I now own a Majestic B eliminator. If I build an external supply, of course I can use lots of heat sinking. My problem was getting results in the compact space under the Radiola 16 chassis.
:
:T.
For B+ considerations...
Here's another great SS regulator for a total of about $2 in parts that will get you up to about 350V dc @ 100ma or so.
I have built it and use it here from time to time... but I replaced R102 with a variable 500k pot.
http://www.antiquewireless.org/otb/resto0504.htm
Bill
:I have built the K-101A kit, and it works fine.
:
:I have simplified the K=101A's B+ ckt and the whole shebang could fit on a smaller printed ckt board (rather than the wooden breadboard that comes with the kit): http://www.enginova.com/batt_elim.htm
:
:Also, the K-101A's C- supply could be eliminated altogether and just use a lithium battery for the bias (if required for a particular radio). The xfmr could then be replaced with just a little 24-volt (or so), CT, single secondary, for the AC supply to the diode bridge for the filament supply.
:
:I also have an ARBE-III battery eliminator, which I use for a bench supply. But that is a little too expensive to use as a dedicated supply for individual radios.
:Doug
:
::Dave, he's speaking of the power supply kit, K-101A you can find on this site:
::
::http://www.tubesandmore.com/
::
::AKA Antique Electronic Supply in Arizona. Page 103 of current catalog; $53.95. I didn't want to get in ahead of Stewart but I wanted to give you my thoughts. I have this power supply and use it ever so often. However it does not always physically fit for use. So I'm thinking about building my own. Have built in the past and modified other ones, got rid of them, etc. My thinking today is if one with a battery set don't want the batteries...well just build a power supply specifically for each set. Norm has offered up some. Another source is jump over to Antique Radio Forum site and find the thread on power supplies. I'm sure Norm had input in that one too. I haven't decided which one I'm going with or when I will. But I have been collecting various parts as I run into them.
::
::Bill VA
:::Stewart: please be more specific on the source for power supply kit. Does it have multiple taps for the varioous voltages required. Than you
:::
:::God Bless,
:::
:::Dave
:::
::::I would purchase the power supply kit from AES and build it. I use one and u should get any voltage for any battery radio God Bless America
Just thought I would offer my comments. I have serveral farm or battery radios, and have purchased the small printed circuit board ones from Novatech Instruments Inc. in Seattle. They run about $50.00, and offer the 1.5 volt filements upward if necessary and up to 90 volts DC B Plus. Amps not that high at .35 but so far have worked very well for me. They are small and can fit out of the way in most cabinets. One feature that I was not sure about was a small flashing led on the board when powered up. But I have learned to like that feature, it reminds me to unplug when I am finished listening to the radios.
Gerald