The following warnings occurred:
Warning [2] Undefined variable $search_thread - Line: 60 - File: showthread.php(1617) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/showthread.php(1617) : eval()'d code 60 errorHandler->error_callback
/showthread.php 1617 eval




Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Headlight Bulb
#1
        [attachment=2646]

Thank you in advance for anyone that might be able to help me.
I have a 1931 RN Saloon 6v twin filament headlights, (the bulbs that you have to focus by sliding in and out to get a decent beam pattern).  
The bulbs are 30w-30w or 35w-35w would do, bottom cap is approx 1.5cm across, 2cm from terminals to glass bulb and pins symmetrical.
Can anybody tell me where I can buy two of these by post?  I think the seven workshop list the correct type beside the other pre focus type.  See photos attached, the bulb I fitted today was the last of my spare ones about 40 yr old and had the number A235 on the cardboard box but can not get any result for this online.
Reply
#2
Try JB Vintage Spares. Is that your bulb first on this page?

http://www.jbvintagespares.co.uk/shop/45...ight-bulbs
Suffolk, UK

1925 Chummy
1934 Box
Reply
#3
30watt x 2 is to high a current rating for an Austin dyamo to keep up with,this is 10 amps for the head lamps plus tail lamps then the current drawn by the coil. A much better solution would be to use L E Ds, a much better light output. Hope this helps.
Reply
#4
Please note that the dynamo does NOT have to 'keep up with' the drain to the headlamps. The battery will supply the deficit. Unless you are commuting in the winter or doing an all-night rally, a discharge during the run back from the pub (or whatever) should be easily handled by the battery, assuming that your battery is in reasonable nick and charged to start with. The seeming general inability to grasp this point has led to a lot of needless worry and the introduction of alternators, which are (for most purposes) a pointless waste of money and effort.

36/36W bulbs are fine. LED headlamp bulbs tend not to give a decent beam when fitted to pre-war reflectors. Important points are to ensure a decent return wire from as close to the bulb as you can get (don't rely on earth return) and to take the high current away from the c.85-year-old contacts in your switch-panel. These are probably getting pretty tired by now, so will welcome the assistance of relays; these are cheap to buy and simple to wire in.
Reply
#5
Good evening Alfie.
I am interested in the type of headlamps fitted to your RN. Currently I am preparing a series of articles on A7 lighting and I have found that the early RN's had Lucas R47's fitted with 'Lucas Graves' double filament dipping headlamp bulbs later being changes to the Lucas type 35/32 still fitted with the 'Lucas-Graves' bulbs and both with 'reeded' glasses.
These bulbs are still available but are more usually known as 'Bosch' bulbs. They have a larger diameter metal body and small and larger rectangular lugs (unlike the round pins normally fitted to bulbs), the purpose of these lugs is to ensure that the bulbs are inserted the correct way up to give the dip/main orientation.
The bulbs that have been identified as available would fit the 'scuttle' lamps (raised in an earlier posting) although there is no facility for focussing them.

Regards from Staffordshire - the creative county.

Stuart
Reply
#6
Keeping it in the Seven family, they are available from our cherished suppliers.
David (A7 Components) has 24/24W BG923 HERE, or Seven Workshop have 35/35W HERE
Reply
#7
I used 36/36 watt headlights with no problems for years. Lots of night driving and very long journeys.
Unless of course your battery's knackered.
Jim
Reply
#8
With 3 brush dynamos low system volts reduces the output so even with standard bulbs balanced if battery somehow gets very low it can be impossible to recover with all the lights connected. If caught far from home can disconnect one lamp. Because of the characteristic some vintage enthusiasts claim more light with low wattage bulbs!
 
A problem is that many sources state that the dynamo should be adjusted to balance the headlamp load  but there is no reference to the associated  bulb wattage and the info hard to find in contemporary publications. Owners need be aware of their particular set up.
 
Original lamps could be focussed so low wattage bulbs were reasonably practicable. Later set ups are often more spread (ie BPF) as required for modern driving. A lot of spread light immediately in front of car is now required  to show lane lines and collections  of curbstones planted  in the roadway
 
With work and study I often did not have time to attend dynamo troubles; usually worn 3rd brush. Used to run car for weeks without charge, including 60 mile  trips home on weekends largely in the dark. Recharged at work, but battery life was not long.....
Reply
#9
(05-05-2018, 07:17 PM)David Cochrane Wrote: Please note that the dynamo does NOT have to 'keep up with' the drain to the headlamps. The battery will supply the deficit. Unless you are commuting in the winter or doing an all-night rally, a discharge during the run back from the pub (or whatever) should be easily handled by the battery, assuming that your battery is in reasonable nick and charged to start with. The seeming general inability to grasp this point has led to a lot of needless worry and the introduction of alternators, which are (for most purposes) a pointless waste of money and effort.

36/36W bulbs are fine. LED headlamp bulbs tend not to give a decent beam when fitted to pre-war reflectors. Important points are to ensure a decent return wire from as close to the bulb as you can get (don't rely on earth return) and to take the high current away from the c.85-year-old contacts in your switch-panel. These are probably getting pretty tired by now, so will welcome the assistance of relays; these are cheap to buy and simple to wire in.

Hearty agreement - most important thing is to make sure the physical wiring is up to the job.
Reply
#10
I'm still confused by the focusing thing. I'm presuming that new A7W reflectors with dedicated APF bulbs are fixed focus and all will be well through lens which have stippled glass and no focusing ability in R47s - i.e. there are no possible adjustments to be made.

But I'm weighing up whether the scuttle lamp system with reasonably good original reflectors can be BETTER than this? (accepting they will be 2' further back!) One just tries the bulb in all three - at night - and picks the best? Surely we must have evidence building up for particular bulbs to ascertain recommendations/experience..?
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)