Does anyone know where I can buy a LM396 voltage regulator? Any place I have found them on the internet the vendor has a $100.00 min. order limit. I would like to get just 2 or 3 of them.
Thanks,
Tom

Tom,
Have you tried DigiKey? (www.digikey.com) Look them up on the web. I frequently purchase small orders from them.
marv

:Does anyone know where I can buy a LM396 voltage regulator? Any place I have found them on the internet the vendor has a $100.00 min. order limit. I would like to get just 2 or 3 of them.
:Thanks,
:Tom

Tom,

You might try Radio Shack.

Mike

:Tom,
:Have you tried DigiKey? (www.digikey.com) Look them up on the web. I frequently purchase small orders from them.
:marv
:
::Does anyone know where I can buy a LM396 voltage regulator? Any place I have found them on the internet the vendor has a $100.00 min. order limit. I would like to get just 2 or 3 of them.
::Thanks,
::Tom

:Tom,
:
:You might try Radio Shack.
:
:Mike
:
:
::Tom,
::Have you tried DigiKey? (www.digikey.com) Look them up on the web. I frequently purchase small orders from them.
::marv
::
:::Does anyone know where I can buy a LM396 voltage regulator? Any place I have found them on the internet the vendor has a $100.00 min. order limit. I would like to get just 2 or 3 of them.
:::Thanks,
:::Tom

Yes, I checked both they don't list this part. It is an adjustable 10amp voltage regulator.
What I need to do is build a power supply for a 5 tube TRF radio that usees 5 globe type 201A tubes. I think that the old globe tubes draw 1 amp at 5volts and the newer '01A tubes draw .25 amps at 5 volts. So if this is correct, I will need more than 5 amp output on my power supply. Could I put two 3amp regulators in parallel?
Thanks for the help
Tom

None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.

:None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.

Gentlemen,

I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.

Radiodoc

Radiodoc,
I don't think I'd recommend the computer supply. These are all switchers, and likely very noisy for these old analog applications. In addition there are normally several other voltages in the same compact package, which when unloaded may radiate unwanted energy. If one were available free, it might be worth a try.
marv

::None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.
:
:Gentlemen,
:
:I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.
:
:Radiodoc
:

:Radiodoc,
:I don't think I'd recommend the computer supply. These are all switchers, and likely very noisy for these old analog applications. In addition there are normally several other voltages in the same compact package, which when unloaded may radiate unwanted energy. If one were available free, it might be worth a try.
:marv
:
Marv,

I am sure you are right. It was just a thought. Perhaps a power supply could be constructed using a low current regulator IC to control an external pass transistor such as a high current darlington. Of course it could be adjustable. Maybe someone on here may have such a diagram.

Radiodoc

:::None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.
::
::Gentlemen,
::
::I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.
::
::Radiodoc
::

Radiodoc,
A very unelegant solid state (positive) regulator can be formed by an NPN transistor with a zener diode and its current limiting resistor in the base circuit. Sourced at the collector, regulated voltage is available at the emitter. Current limiting resistor must be set to allow specified zener current and transistor base current. A Darlington pair would also work well, if a 10 amp variety is available, or a 10 amp version could be created by 2 power transistors. This may be a little more elegant/costly than required.
marv

::Radiodoc,
::I don't think I'd recommend the computer supply. These are all switchers, and likely very noisy for these old analog applications. In addition there are normally several other voltages in the same compact package, which when unloaded may radiate unwanted energy. If one were available free, it might be worth a try.
::marv
::
:Marv,
:
:I am sure you are right. It was just a thought. Perhaps a power supply could be constructed using a low current regulator IC to control an external pass transistor such as a high current darlington. Of course it could be adjustable. Maybe someone on here may have such a diagram.
:
:Radiodoc
:
::::None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.
:::
:::Gentlemen,
:::
:::I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.
:::
:::Radiodoc
:::

:Radiodoc,
:A very unelegant solid state (positive) regulator can be formed by an NPN transistor with a zener diode and its current limiting resistor in the base circuit. Sourced at the collector, regulated voltage is available at the emitter. Current limiting resistor must be set to allow specified zener current and transistor base current. A Darlington pair would also work well, if a 10 amp variety is available, or a 10 amp version could be created by 2 power transistors. This may be a little more elegant/costly than required.
:marv
:
:::Radiodoc,
:::I don't think I'd recommend the computer supply. These are all switchers, and likely very noisy for these old analog applications. In addition there are normally several other voltages in the same compact package, which when unloaded may radiate unwanted energy. If one were available free, it might be worth a try.
:::marv
:::
::Marv,
::
::I am sure you are right. It was just a thought. Perhaps a power supply could be constructed using a low current regulator IC to control an external pass transistor such as a high current darlington. Of course it could be adjustable. Maybe someone on here may have such a diagram.
::
::Radiodoc
::
:::::None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.
::::
::::Gentlemen,
::::
::::I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.
::::
::::Radiodoc
::::

I was thinking of a computer power supply also. I have about 4 or 5 junk ones rated at 20 to 25 amps at 5volts. I have looked inside of them and none of them have transformers that look large enough to supply 20 amps. How do they do it? If I use the complete computer power supply just for the "A" supply this would be a large unit by the time I get the "B" and "C" power supplies built. But I think I will give it a try. Some others have offered ideas like transistors and 555 timmers and other more involved ideas, but I am just a beginner and could no way come up with a circut like that.I would think someone has built a simple high current (6 to 10 amp) "A" supply to power a 5 tube TRF.

Tom

::Radiodoc,
::I don't think I'd recommend the computer supply. These are all switchers, and likely very noisy for these old analog applications. In addition there are normally several other voltages in the same compact package, which when unloaded may radiate unwanted energy. If one were available free, it might be worth a try.
::marv
::
:Marv,
:
:I am sure you are right. It was just a thought. Perhaps a power supply could be constructed using a low current regulator IC to control an external pass transistor such as a high current darlington. Of course it could be adjustable. Maybe someone on here may have such a diagram.
:
:Radiodoc
:
::::None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.
:::
:::Gentlemen,
:::
:::I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.
:::
:::Radiodoc
:::

:::Radiodoc,
:::I don't think I'd recommend the computer supply. These are all switchers, and likely very noisy for these old analog applications. In addition there are normally several other voltages in the same compact package, which when unloaded may radiate unwanted energy. If one were available free, it might be worth a try.
:::marv
:::
::Marv,
Radiodoc, did you sell an old 40's radio to Bernie's Stuff? Could you contact us if you did? Thanks
::
::I am sure you are right. It was just a thought. Perhaps a power supply could be constructed using a low current regulator IC to control an external pass transistor such as a high current darlington. Of course it could be adjustable. Maybe someone on here may have such a diagram.
::
::Radiodoc
::
:::::None of the guys that sell one at a time list this one. The closest thing I found is a LM338k listed in Allied Electronics. Its a 5a adjustable.
::::
::::Gentlemen,
::::
::::I wonder if the 5-volt output of a computer power supply would work. There are tons of these in the surplus computer market rated 10 amps and up.
::::
::::Radiodoc
::::

Have you thought about using a mosfet? A 2SK1082 ca be found pretty easily on line and also in a computerpower supply. its rated for like 8 amps i think. research it at http://www.nteinc.com/specs/2300to2399/NTE2377.html

:You can turn down the voltage with a siple pot. on the gate. (last method can be a little touchy)
:Or it can be driven by pulse width modulation using a 555 timer chip. schematics can be found every where.

AN IRF530 has a 100v 16amp rating and can be found

http://www.oselectronics.com/ose_p84.htm for a couple of bucks. they also sell high voltage caps and other antiquie radio repair parts.

Hi Tom

In the past I have obtained samples of parts directly from the manufacturer or distributor, FREE!

Just Google LM396 and find the suppliers that provide samples. Most of them allow you to request samples online.

If you cannot get samples, there are several electronic suppliers and wholesaler's close to where I live here in Peterborough, Ontario Canada. I would be happy to pick them up and send them to you.

Gary

Gary

:Does anyone know where I can buy a LM396 voltage regulator? Any place I have found them on the internet the vendor has a $100.00 min. order limit. I would like to get just 2 or 3 of them.
:Thanks,
:Tom

*************************************************************************************************************************************************************************************************
I guess the first thing to investigate is if your tubes are the straight 201’s with the raw tungsten fil versions or the newer 201A’s with the thorium passsivated fils. A big difference of the original requiring 1 amp or the improved chemical passivation dropping the fil current requirements down to only 250 mils. So test them out one by one and see which figure of comsumption is presented by the units. Not having a lab power supply
of that capacity, 3 series alkaline “D”cells ( new ones can pump out 5-6 amps short time spurts) should be close enough in voltage to differentiate on a series ammeter to see “what ‘cha got” in the way of current consumption.
As for the power supply, AM radio would certainly be desirous of a linear design of supply, It is very common practice to use a shunt series transistor combo to handle the brute power route along with the fine regulation of a 3 terminal device feeding it.
Refer to the URL below for the second circuit if of the lower current requirements or to the third if the whole 5A+PLUS is required.

http://ourworld.compuserve.com/homepages/Bill_Bowden/page12.htm

73’s de Edd

**********************************************************************************************************************************************************************************************

:Does anyone know where I can buy a LM396 voltage regulator? Any place I have found them on the internet the vendor has a $100.00 min. order limit. I would like to get just 2 or 3 of them.
:Thanks,
:Tom

We have alot of older obsolete ic's where I work and that number rings a bell. Let me check it out and if I can find some I'll let you know.
Russ