:Hello, I recently got a Heatkit BE-3 battery eliminator. It is rated for 6 volts 10 amps. The volt meter goes from 1-15v and the amp meter goes from 1-15a. My question is that when I first powered it up from sitting for many years it was only reading 4 volts and after leaving it on for about an hour it is now reading 10.5 volts without a load. When I hook up my Zenith 6 volt battery radio to the battery eliminator the voltage drops to about 3.5 volts with about 1.5 amps. The zenith is a 4-b-131 and works on 6 volts and draws 1.7 amps. Why is the voltage droping so much, I have the voltage knob turned all the way up. Is it possible that the electritic capacitor needs to be reformed or is no longer any good? There are no other parts that look like they could go bad, how do I increase the voltage with a load on my battery eliminator.
:Thanks
:David
Considering the BE-3 to be the same order of design as its upgrade , the BE-4….refer to :
http://web.archive.org/web/20040127103557/www.triplanetary.freeserve.co.uk/diagrams/be-4.gif
It would seem logical that old warhorse was deficient in its filtering capacity with the type of electrolytics available on those days.
Am I correct that there is a marking of a the selector switch of 12 Volt operation of the supply at a like reduced current capability also ?
The other unknown thing is if the unit was using silicon diodes for the power rectifiers or was the unit of such age that it was using old large plate selenium rectifiers ?
The only thing that I could suggest would be to advantage in upgrading would be the replacement of the old obviously deficient electrolytics with some of the modern computer grade electrolytics, even if of newer surplus stock.
( And no, I wouldn’t expect a successful reforming action of your old units….as that is more successful on high voltage electrolytics.)
The second thought would only be if the unit was originally utilizing large plate selenium rectifier stacks and that would be to replace them with solid state diodes, and more specifically, Schottky diodes as used in modern switchmode power supply designs.
Up date me on what is inside the BE-3….also look for some code dates on parts to see how old that unit is.
73’s de Edd
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:Hello, I recently got a Heatkit BE-3 battery eliminator. It is rated for 6 volts 10 amps. The volt meter goes from 1-15v and the amp meter goes from 1-15a. My question is that when I first powered it up from sitting for many years it was only reading 4 volts and after leaving it on for about an hour it is now reading 10.5 volts without a load. When I hook up my Zenith 6 volt battery radio to the battery eliminator the voltage drops to about 3.5 volts with about 1.5 amps. The zenith is a 4-b-131 and works on 6 volts and draws 1.7 amps. Why is the voltage droping so much, I have the voltage knob turned all the way up. Is it possible that the electritic capacitor needs to be reformed or is no longer any good? There are no other parts that look like they could go bad, how do I increase the voltage with a load on my battery eliminator.
:Thanks
:David
:Try this schematic--http://www.vintage-radio.info/heathkit/diagrams/be-4.gif. The model that I have is only a 6-volt model and does have a very large sellinum rectifer in it.
:Thanks
:David
I have an update posted at:
http://www.nostalgiaair.org/Forums/Messages/920/M0037920.htm
73's de Edd
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
:Try this schematic--http://www.vintage-radio.info/heathkit/diagrams/be-4.gif. The model that I have is only a 6-volt model and does have a very large sellinum rectifer in it.
:Thanks
:David
First replace electrolytics and test selenium rectifiers. They shouldn't allow any reverse current of any kind. If you use your meter's X10,000 ohm scale and you get leakage even in the millions of ohms, then the rectifiers are bad. Replace them. If they don't have reverse leakage, though, try them out with the new electrolytics. If current is still low, then the units are faulty (even if they don't have reverse leakage..they do deteriorate on occasion, especially if subjected to moisture). If the unit puts out adequate power, though, leave the original rectifiers alone. They can take shorts and surges and all sorts of stuff, and they last a fairly long time. They cool themselves naturally--due to all the fins. Place a fuse on the output of the power supply that is rated for the power supply's maximum output. This will prevent damage in the event of a short (say your vibrator sticks). Place a fuse on the radio that's rated at 1 or 2 amperes above the radio's normal operating current, to protect the radio as well.
Thomas
Testing a Selenium with a ohmeter is meaningless, they have to be tested with a load on them, they do not form the junction without a load, they are not like silicon diodes. The best way to test ones this size is with a 12 volt battery, and a 12 volt bulb which draws at least 2 amps, a car headlite would work fine. Put the bulb in series with the selenium and connect to the battery, now reverse the connections at the battery. One way the bulb should light, reverse the connection and it should not. If the bulb stays lit in both directions or if it doesn't light the seleniun is bad. Each section of the selenium should be checked like this.
Dave
:They still use selenium rectifiers in modern battery chargers. Both of my parents' battery chargers are about 20 years old and the rectifiers still work perfectly. They use them all the time. My sister has one that's from about 1999, and it has a 20 ampere selenium rectifier. It works quite well, too.
:
:First replace electrolytics and test selenium rectifiers. They shouldn't allow any reverse current of any kind. If you use your meter's X10,000 ohm scale and you get leakage even in the millions of ohms, then the rectifiers are bad. Replace them. If they don't have reverse leakage, though, try them out with the new electrolytics. If current is still low, then the units are faulty (even if they don't have reverse leakage..they do deteriorate on occasion, especially if subjected to moisture). If the unit puts out adequate power, though, leave the original rectifiers alone. They can take shorts and surges and all sorts of stuff, and they last a fairly long time. They cool themselves naturally--due to all the fins. Place a fuse on the output of the power supply that is rated for the power supply's maximum output. This will prevent damage in the event of a short (say your vibrator sticks). Place a fuse on the radio that's rated at 1 or 2 amperes above the radio's normal operating current, to protect the radio as well.
:
:Thomas
Selenium rectifiers are still alive and well at least at one place in the US of A. For kicks check out http://www.cougarelectronics.com/index.html
Radiodoc
:Didn't know that new chargers still used selenium. I recently wrote an article about this for Electric Radio (to be published soon) and found a company in India still making selenium stacks. I guess that most chargers are now made in China or Taiwan and may still make selenium devices there. Due to EPA issues, selenium is difficult to process in the USA. Selenium should last 20 yrs, but a Heathkit from the early 50s is already over 50 yrs. Reverse ohm-meter reading may not tell you much. Selenium has a higher leakage level than silicon and at 6 or 12 volts, leakage isn't a major issue. The biggest problem is that the forward loss increases with aging. This will prevent you from getting full rated current. As you increas the load, the voltage will just drop off.
:Rich
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:
:
::They still use selenium rectifiers in modern battery chargers. Both of my parents' battery chargers are about 20 years old and the rectifiers still work perfectly. They use them all the time. My sister has one that's from about 1999, and it has a 20 ampere selenium rectifier. It works quite well, too.
::
::First replace electrolytics and test selenium rectifiers. They shouldn't allow any reverse current of any kind. If you use your meter's X10,000 ohm scale and you get leakage even in the millions of ohms, then the rectifiers are bad. Replace them. If they don't have reverse leakage, though, try them out with the new electrolytics. If current is still low, then the units are faulty (even if they don't have reverse leakage..they do deteriorate on occasion, especially if subjected to moisture). If the unit puts out adequate power, though, leave the original rectifiers alone. They can take shorts and surges and all sorts of stuff, and they last a fairly long time. They cool themselves naturally--due to all the fins. Place a fuse on the output of the power supply that is rated for the power supply's maximum output. This will prevent damage in the event of a short (say your vibrator sticks). Place a fuse on the radio that's rated at 1 or 2 amperes above the radio's normal operating current, to protect the radio as well.
::
::Thomas
Many selenium devices are still being made in this country and we are a large producer of selenium. They are the ideal choice for welders, battery chargers, plating power supplies, or anyplace a heavy duty rectifier is required, they can be direct short circuited for short periods of time with no damage. They also exhibit a slow start due to the fact the junction has is reformed for each use, they do not produce the RFI that silicon does and are not susceptible to powerline surges. I have not seen any evidence that they age although there are many stories to that effect. They are the ideal rectifier, too bad they are no longer commonly used radios due to manufacturing costs. If you care to email me I can send some data on selenium.
Dave
:Didn't know that new chargers still used selenium. I recently wrote an article about this for Electric Radio (to be published soon) and found a company in India still making selenium stacks. I guess that most chargers are now made in China or Taiwan and may still make selenium devices there. Due to EPA issues, selenium is difficult to process in the USA. Selenium should last 20 yrs, but a Heathkit from the early 50s is already over 50 yrs. Reverse ohm-meter reading may not tell you much. Selenium has a higher leakage level than silicon and at 6 or 12 volts, leakage isn't a major issue. The biggest problem is that the forward loss increases with aging. This will prevent you from getting full rated current. As you increas the load, the voltage will just drop off.
:Rich
I heard those same positive points back in the late 60s when I was at Westinghouse Semiconductor. We were still making selenium and some folks wanted to continue. There are reasons why virtually no modern electronics use selenium: efficiency, size, toxicitiy. They were great in old battery chargers because you could rub the clips together and get a spark to tell if the charger was ON. I still doubt that anyone is making selenium rectifiers in the USA; importing, maybe. Selenium is a rugged rectifier, but once you have one fail under load, it's an unforgettable experience! I can buy a 1 amp / 400 V silicon diode (1N4004) for a dime... what's an equivalent selenium going to cost? I can suppress the diode switching noise (if that's a problem) for another dime. Selenium is not hermetically encapsulated, so the environment (moisture and air) cause it to age. Sorry, you can't sell me. Rich
:Rich
:
:Many selenium devices are still being made in this country and we are a large producer of selenium. They are the ideal choice for welders, battery chargers, plating power supplies, or anyplace a heavy duty rectifier is required, they can be direct short circuited for short periods of time with no damage. They also exhibit a slow start due to the fact the junction has is reformed for each use, they do not produce the RFI that silicon does and are not susceptible to powerline surges. I have not seen any evidence that they age although there are many stories to that effect. They are the ideal rectifier, too bad they are no longer commonly used radios due to manufacturing costs. If you care to email me I can send some data on selenium.
:
:Dave
:
:
::Didn't know that new chargers still used selenium. I recently wrote an article about this for Electric Radio (to be published soon) and found a company in India still making selenium stacks. I guess that most chargers are now made in China or Taiwan and may still make selenium devices there. Due to EPA issues, selenium is difficult to process in the USA. Selenium should last 20 yrs, but a Heathkit from the early 50s is already over 50 yrs. Reverse ohm-meter reading may not tell you much. Selenium has a higher leakage level than silicon and at 6 or 12 volts, leakage isn't a major issue. The biggest problem is that the forward loss increases with aging. This will prevent you from getting full rated current. As you increas the load, the voltage will just drop off.
::Rich
:
Selenium is also used for many other things like coloring and decoloring glass (this is amazing). Selenium is the bi-product of copper production, and is constantly being produced in this country.
Thomas
Dave
:Well, then you have to read his data sheets, which are up-to-date, and show selenium devices still being produced in this country. It also does tell of how selenium is toxic in large amounts, or when it is vaporized (like when you fry a rectifier). They are great devices, though, and I always short my battery charger clips together to see whether it's on or not. It's also fun to see the sparks.
:
:Selenium is also used for many other things like coloring and decoloring glass (this is amazing). Selenium is the bi-product of copper production, and is constantly being produced in this country.
:
:Thomas
When I read articles, though, I, too, cratique them. I used to believe that when it is written in a book, it is fact, like most other people. I have since found, though, that there are a lot of people out there writing books, who have no idea what they are talking about. Take, for instance, anyone who writes about Chevrolet 216.5 engines, or Chiltons manuals. Often the information I find about my engine is based on assumptions and myths (I am also amazed at how many people out there believe that my engine lasts forever...."they don't build them like they used to." Thank God!). If you ever read a Chilton's manual, it will most likely leave you more confused than you were before you read the manual.
I have several books from the 1960s which explain how to repair old radios. It is no wonder that so many people have come to believe that tube equipment is inferior. Nowhere in any of these manuals does it mention anything about capacitor leakage (which causes a TON of radio trouble I come across). They only talk about replacing tubes and broken wires and volume controls, ...perhaps drifted resistors. Still, since these books were published by big companies, many probably took all of the information as fact. Who knows, though. Since AM radios were used a whole lot more back then, maybe tubes did burn out more often. All I can say is that it is VERY rare for any of my tubes to burn out. I use my Silvertone phonograph almost daily, sometimes for several hours at a time, and yet the 1940 tubes are all still going strong (save the eye tube which I replaced because it was dim).
Thomas
:Are you talking about your article or another article?
:
:When I read articles, though, I, too, cratique them. I used to believe that when it is written in a book, it is fact, like most other people. I have since found, though, that there are a lot of people out there writing books, who have no idea what they are talking about. Take, for instance, anyone who writes about Chevrolet 216.5 engines, or Chiltons manuals. Often the information I find about my engine is based on assumptions and myths (I am also amazed at how many people out there believe that my engine lasts forever...."they don't build them like they used to." Thank God!). If you ever read a Chilton's manual, it will most likely leave you more confused than you were before you read the manual.
:
:I have several books from the 1960s which explain how to repair old radios. It is no wonder that so many people have come to believe that tube equipment is inferior. Nowhere in any of these manuals does it mention anything about capacitor leakage (which causes a TON of radio trouble I come across). They only talk about replacing tubes and broken wires and volume controls, ...perhaps drifted resistors. Still, since these books were published by big companies, many probably took all of the information as fact. Who knows, though. Since AM radios were used a whole lot more back then, maybe tubes did burn out more often. All I can say is that it is VERY rare for any of my tubes to burn out. I use my Silvertone phonograph almost daily, sometimes for several hours at a time, and yet the 1940 tubes are all still going strong (save the eye tube which I replaced because it was dim).
:
:Thomas
By the way, do you actually make selenium rectifiers in the USA? How much does a selenium unit cost that would replace a 10 cent silicon diode?
Rich
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:Thomas
:This is very interesting and goes to show how myths are perpetuated. He we have an example of someone who wrote an article for a magazine which will be read by millions, I have to wonder how accurate the article was, and how extensive the research was. From the response there must be very little accuracy and no research. Most articles I have seen on selenium rectifiers should be considered fiction. Sorry about the rant but just because something is published does not mean it is true.
:
:Dave
:
:
:
::Well, then you have to read his data sheets, which are up-to-date, and show selenium devices still being produced in this country. It also does tell of how selenium is toxic in large amounts, or when it is vaporized (like when you fry a rectifier). They are great devices, though, and I always short my battery charger clips together to see whether it's on or not. It's also fun to see the sparks.
::
::Selenium is also used for many other things like coloring and decoloring glass (this is amazing). Selenium is the bi-product of copper production, and is constantly being produced in this country.
::
::Thomas
http://www.nostalgiaair.org/Forums/Messages/920/M0037920.htm
….you might not have seen it. At only 79 cents a copy with plenty of voltage rating headrooom:
4700 ufd 35 VDC:
:http://www.bgmicro.com/prodinfo.asp?sid=016883101851851924119644&prodid=CAP1068&page=1&cri=1068&stype=3
Multiple parallel units hold up better in the ESR perspective….. but they are really not being taxed in this application.
73’s de Edd
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:Dave:
:I sure wish Electric Radio were read by millions, but it's like to be a couple of thousand.
:
:By the way, do you actually make selenium rectifiers in the USA? How much does a selenium unit cost that would replace a 10 cent silicon diode?
:
:Rich
:
:&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
:
::Thomas
::This is very interesting and goes to show how myths are perpetuated. He we have an example of someone who wrote an article for a magazine which will be read by millions, I have to wonder how accurate the article was, and how extensive the research was. From the response there must be very little accuracy and no research. Most articles I have seen on selenium rectifiers should be considered fiction. Sorry about the rant but just because something is published does not mean it is true.
::
::Dave
::
::
::
:::Well, then you have to read his data sheets, which are up-to-date, and show selenium devices still being produced in this country. It also does tell of how selenium is toxic in large amounts, or when it is vaporized (like when you fry a rectifier). They are great devices, though, and I always short my battery charger clips together to see whether it's on or not. It's also fun to see the sparks.
:::
:::Selenium is also used for many other things like coloring and decoloring glass (this is amazing). Selenium is the bi-product of copper production, and is constantly being produced in this country.
:::
:::Thomas
Now, the rectifier in question in this thread is for a low voltage source, not a B rectifier in a radio. Here it may make sense to test with a small lightbulb. I still think that meter testing is also advisable, as a very small reverse current can slowly damage an electrolytic, and yet it may not be able to light a lightbulb.
Thomas