A couple of really early battery eliminators

It's sensible to assume that mains power was not too rare when battery eliminators first appeared.

Below are a couple, the first using ebonite in its construction so this would perhaps place it around 1925 to 1927.

 Battery Eliminator or Charger (continental), maybe a Philips Model 1009 ?


 The views above show an old battery charger/eliminator (covered in half an inch of dust when I picked it up) which I bought at an Antique Fleamarket in Antwerp (see also the meters, I got from another stall at the same place ...elsewhere on this website).

Similar devices to this one could be used to replace the HT battery in an old radio in the late 20s and early to mid-30s. This one has a nice metal label which proclaims that it's a "REDRESSEUR DE COURRANT B.B DEPOSE" for 110 volt 50 Hz mains and provides 40-80-120 volts @ 0.1Amp and and 2 to 12 volts @ 1.3Amp. It originally had two Philips tubes, types "1010" and "1011" fitted in the pair of B4 sockets in the ebonite top. There's a nice three way knife switch on the top and four screw terminals for connecting up to the radio. When the switch is one position an accumulator from 2 to 12 volts may be charged. When in the other the unit can replace the radio's HT battery (or maybe charge an HT battery, which were not too common). In the latter position it's a battery eliminator and in the first it will charge the filament supply 2 volt accumulator. One cannot do both at the same time as it explains on the label. I suppose it can also charge lead acid HT batteries (these were not very common)...maybe that's it's prime purpose, just charging either battery as it may be a source of hum without additional components for smoothing?

I couldn't find details of the two valves in my reference books but Trevor Gale's website gave a query form and an answer provided the 1010 is a double diode rated at 60volts, 3.5Amp (some filament emission!) with a filament supply of 1.8 volts 3.5Amp.

The 1011 wasn't listed but a recent email from Peter Hughes in Australia has solved the mystery. The 1011 is a curent regulator tube, known as a barretter and the unit may be a Philips Model "1009".

I wonder if the unit just pre-dated the disk or electrolytic rectifiers which were available in 1928?

I asked the chap I bought it from if he knew what it was and he just shrugged but he said wanted 300BF for it. I offered 200 (£3.50) which he accepted but I felt very guilty as the smallest I had was a 2000 Franc note. As I took the very heavy dusty old box, with its mains lead cut off short and the handful of change in notes. which he very deliberately counted out, I jokingly asked if it was guaranteed. He replied after a few seconds of thought (with a "poker face"), "two years". I found most Flemish Belgians invariably had that sort of sense of humour. I was at a small bar in Tournai three months earlier with a couple of friends and my 14 year old son. We ordered three Jupilers and asked the barman what he'd recommend for Jeremy. He thought for a few seconds and said a lot of flemish words then ushered us back out to a pavement table. Soon he appeared with three beers and then disappeared back into the bar to reappear. a moment later, with the same beer but in a glass the size of a thimble. We proceeded to quench our thirsts (it was very hot) and Jeremy who looked a bit taken aback sipped daintily at his. After a few moments there was the sound of merriment inside shortly followed by the barman who emerged with a tray, on which was a fourth (normal sized) Jupiler.


 Philips High Tension Supply Unit Type 372

 An addition to my collection of battery eliminators is an HT unit from Philips dating from perhaps from around 1928, when mains power was getting more common. This model is rated at 240volts 50Hz and would have been quite expensive, as were Philips mains powered radio sets.

Many thanks to Stephen Scott for giving it to me.

Construction is typically Philips, being made in such a way as to make it nearly impossible to dismantle without soldering iron and copious notes and drawings as everything is connected with brown insulated wire and has had its mains connector cut off and a mains lead fitted (now cut off) clearly indicating a modification to get round the absence of a mating mains plug.

Connections are made to the four terminals at the bottom of the panel as detailed in the instructions in the second picture below. A variable HT supply is provided for the output valve and a 3-position switch selects a convenient HT voltage for the other valves.

The 3-pin socket is for the rectifier valve. This predates the metal rectifier which appears in later models of battery eliminator (and probably also pre-dates double-diode rectifiers). Only 3 connections are provided. Two for the filament which is also the cathode (and HT positive) and one for the anode (the high voltage AC connection, making a single diode and thus the circuit is a half wave rectifier). I must admit to not having seen a 3-pin valve other than the tiny B3G EA52 types.

Rod Hawkins kindly sent me these pictures of the 3-pin rectifier valve used in this Philips battery eliminator.




You can see from the two pictures below that there appears to be two transformers. I'm inclined to believe that one is for the rectifier valve heater and the HT but the second isn't a transformer, but a choke which then was by far the best way of smoothing the HT supply.


 Below... note the pragmatic design feature... the piece of wood holding the tin box in place. I wonder if this was necessary to break the magnetic circuit and prevent the box acting as a coil and inducing hum into the output? Imagine the design department trying to deal with a change following user complaints... "I've fixed the hum problem boss"..."How did you manage that Johann?".. "You don't want to know boss..."



 I've included the above picture to show you connections disappearing into the metal box between the transformer and choke.

I guess this box carries a couple of capacitors, one for the reservoir and the second for smoothing. The wirewound rheostat is for setting the main HT and the wound component is a set of three resistors for setting the HT level for the second output in conjunction with the three-position switch.
See even more battery eliminators