VARLEY Battery Eliminator

[David Simpson]

Folks, Ef'd off with the HSVT, so have taken a wee break. This B/El also came from my HSVT pal.
Does anyone know anything about the VARLEY ? Its in a bit of a state and the mains lead is totally perished. It'll be easy enough to work out the circuitry, but if anyone has a copy of the circuit diagram, it would speed things up. It contains a Mullard DW2 and some ancient capacitors & resistors. A wooden chassis and ebonite resistor & terminal mountings. All inside a thin rusty steel cabinet. Late 20's/early 30's ?

Regards, David

[Peter.N.]

Looks a pretty hefty power supply, any idea what battery it eliminated?

Peter

[karesz*]

Peter these eliminator is clearly for anode battery + usualy such heating battery elimination. Delivers maybe between 80-120Volts more values and ie 4Volt, similar as these Denmark unit from 20s or some Heathkit models...
Karl

[DuncanLeece]

I am the lucky chap for whom David is sorting out this eliminator, in addition to my Mullard HSVT described on another thread. What a good mate he is! Public round of applause?

Anyway... David: This was made by London manufacturer Radio Instruments, hence the RI logo. For a while they seem to have been in partnership with another company, Varley, and some early RI equipment shows both names. Something in my memory says Varley made batteries?

RI listed quite a few models of radios back in the 1920s, and my guess is this thing was made as an accessory for them. But I could easily be wrong, as I believe they made non-radio equipment too, for military and industrial use.

Don't know if that helps?

best wishes
Duncan

[Radio Wrangler]

The scale of the transformer makes it look capable of eliminating a far larger battery current than most battery radios would need.

The full-wave rectifier valve fits in with it being an HT supply. Lower voltages would use metal, mercury or argon rectifier devices.

David

[ms660]

60 ma max for the DW2.

Lawrence.

[karesz*]

Duncan, a Varley traded battery sortiment does existent nowadays too.
I fand over Varley (Battery Eliminator) (position 109) only one information_not very usable...
Karl

[Peter.N.]

I remember Varley as manufacturers of accumulators. That transformer looks a bit of an overkill for 60ma.

Peter

[David Simpson]

Folks, Inside is a thumping great metal encapsulated TCC multi capacitor. Its stamped 11uF & a test voltage of 500V DC. I've never ever seen one before, nor have my local vintage chums. The term marked E isn't connected to the casing, and resistance & capacitance readings between terminals wander all over the place.
Anyone any ideas please ?
Its probably duff, but hopefully it might be stuffable.

Regards, David

[HamishBoxer]

Possibly 5 caps in 1? Careful distmantling might reveal more.

[G6Tanuki]

Varley is indeed a name I still associate with storage-batteries: their "Red Top" is the battery-of-choice in many motorsport applications.

I wonder if this is the company that made your battery-eliminator: http://www.historywebsite.co.uk/Muse...em/history.htm

Some of these kind of units were designed so they could be switched either to provide HT (B-battery as the Americans would call it) to a receiver, or to provide a trickle-charge to a LT-accumulator (A-battery) when the radio wasn't actually being used.

[AC/HL]

Coincidence I think, the last sentence mentioned that they were part of Ever Ready from the 1920s on.

[Ed_Dinning]

Hi David, quite a beast and it does indeed look like several caps in one. This was common practice fro battery eliminators that would have resistors between sections to give very approx. the various voltage taps (ohms law not withstanding!).

Ed

[David Simpson]

Thanks Guys, for your helpful answers. An additional thanks to G6Tanuki for the TEC article.
As folk might have gathered, I had a long association with RAF Cosford. That meant also a long association with nearby Wolverhampton. What a hive of industry. Also a sharp contrast between the inner industrial area and the mansions & estates on the periphery.
Back to the Batt. El. - thankfully, the rest of the major components are in good order, despite their age, but the wooden chassis has seen better days.

Regards, David

[David Simpson]

Some more pictures, & a sketch of circuit diagram - as found.
A Double Choke eh ? Wonder if Ed Dinning has ever seen one ? Two separate wound bobbins on the same core. Yes, it might be considered a 1:1 transformer, but this is how it was wired in the HT +ve & -ve circuitry. Counter-wound to cancel out ripple ?

Regards, David

[Ed_Dinning]

Hi David, no, not seen double chokes on kit that old, but there were air cored ones used as suppressors on Murphy sets in the mains in line.

In modern SMPS it is common to use these chokes to improve cross regulation between 2 different output supplies, but I would not have thought that necessary on this piece of kit.

Ed

[Mr Moose]

Hello,

I found this advert for a do-it-yourself version of your power supply on the back of Wireless Constructor magazine for March 1927.

It uses four (six) separate capacitors rather than the single block one, nominally from the circuit they are 4uF 4uF 2uF and 1uF making the 11uF in all. (The picture shows the 4uF condensers as made from two 2uF ones making six in all.)

Also the detector supply is switched rather than three separate terminals.

Yours, Richard

[David Simpson]

Many thanks, Richard, for the Varley info.
The B/El has been reassembled and brought up to 21st century usage standard. I.e. - safe to use & tested by my PAT tester.
The double choke arrangement produced more HT ripple than was acceptable, no matter how the coils were arranged circuit-wise. So just one coil of 10H was used in a conventional Cap. input filter. That, plus two newish 47uF electrolytic capacitors, produced a lovely smooth ripple-free HT. The TCC 4 in 1 capacitor was dumped. I tried to melt out the pitch with a heat gun, with a view to re-stuffing, but soon discovered some horrible smelly phenolic type encapsulation of the capacitors which smoked badly without the pitch running out. Bollox to that ! too poisonous, I reckon. Anyway, put in an old decent TCC 8uF to provide additional smoothing to the lower detector voltage & to look the part.
The heater rheostat(with it's "live" shaft) was replaced with just a new high wattage dropper. As the B/El with just be running off decent 230/240V mains. An HT switch, Heater Fuse & HT Fuse were added. Modern wiring & components are well hidden underneath, so viewing from the top, the 1930 ish look remains.

Regards, David

[McMurdo]

Varley have products listed in one of my 1930's catalogues, and include tuning coils, solenoids, mains transformers, record player pickups, power resistors and other wound products. My only dealings with them were when they made Post Office and continental relays, and those flip switches you see on GPO telephone exchanges. I remember seeing them in RS or Farnell until quite recently as 'Keyswitch Varley'. I think they were taken over by FKI Industries (Fisher Karpark) . They also made electromagnetic clutch-brakes and other diverse objects.

[David Simpson]

I guess that Varley, like Lissen, Lewcos, & TCC, etc., were in at the start of radio construction back in the late 20's.
I've attached a revised circuit diagram. I wonder how popular HT Batt. El.'s became before internal HT circuitry was incorporated into domestic sets in the 30's.

Regards, David