If dual filament bulbs are fitted can these be wired directly to the dipswitch or is there need for a dipping solenoid?

Paul, If you have dual filament bulbs there is no need for a solenoid to dip the lights so you can use the existing dipswitch. A7s at some stage in their development (1933 I think)had a dipping solenoid in one of the headlights and the other head light went out. Are you referring to that type? The RN box saloon had double dipping Lucas Graves bulbs in 1932 which were superior to the type fitted later as I have mentioned above. Both types were pretty hopeless though!
Dave.

Location: Sheffield

Hello. Personally I wouldn't subject the dip-switch contacts to the current (typically c8-12amps) and would always use a relay. I believe David Cochrane of A7 Components sells a suitable unit.
Regards
Stuart

Location: Staffordshire, the creative county.

Paul,
Stuart and David C are real experts so you have good advice from them. I haven't had any problems with my box saloon dipswitch, the saloon having been in the family for the last 80 years, admittedly using 12v for the last 14 so lower current passing through it. Similarly no problems with burning of contacts in the side/head switch on the switchboard.
Cheers,
Dave.

Location: Sheffield

My export car has two dipping reflectors, but presumably no cars are still running about with a single dipping reflector. How have they all been wired?

The original RP dipping reflector switch can be connected for a changeover function as reqd for two filaments but as pointed out the contacts are meagre for the current continuously, and heavy wire to would look wrong. Operation can be achieved with a non original solenoid (which suitably placed may reduce the voltage loss) but an automotive switch, concealed if thought necessary, is more simple, and no current is wasted..

Location: Auckland, NZ

Good evening (morning) Bob. I have never seen an offside headlamp engineered to take a solenoid dipping mechanism. Some original UK cars are still set up with N/S dipping O/S off but the way round the now defunct MoT test was to have them both permanently on 'main' but adjusted for the dip position only.
Other cars use the 7" 'Wipac' sealed beam or BPF units but given the number that have been sold many cars must use the replacement reflectors from the 'Seven Workshop'.
Regards
Stuart

Location: Staffordshire, the creative county.

Hi Dave,
Many thanks for the response. To add a little more detail.
I have a '37 Ruby powered by a 6 volt battery. The headlamps have twin filament bulbs but currently, in the absence of a dipswitch, there is no option to utilise the full potential of these bulbs. Both lamps are powered simultaneously when switched.
Having now purchased a dipswitch I just need to know whether this will be sufficient to realise my objective or do I also need a relay as suggested in one of the responses.
Your advice awaited & much appreciated. Thank you.

Current I = Watts divided by Volts. Thus you can work out what current in amps is flowing through your switch by adding up the headlight watts and dividing by the Volts (6).

Older car switches were usually robustly built with quite large chunky bits of brass as contacts, but due to even small amounts of inevitable sparking when the contacts make and break because of the current flow then they will burn and eventually need the burn cleaning off. Relays are easier and cheaper to replace than switches.

It is best to use the switch to operate a relay so that the switch is handling only a very very small current. A separate wire is then taken from a convenient point near the battery direct to a fuse then to the (power) input of the relay and a wire from the relay output to the headlight. relays are quite small and easily hidden. They can be pulled out of their holder and a new one just plugged in if they fail.....they come in all sizes of current handeling e.g. assume 60 Watt headlamp X2 = 120 Watts divide by 6 = 20 amps......a 30 amp relay would easily handle this.
Better still to save plunging into sudden darkness when running down the motorway at 70mph (?????) use 2 relays, one for each headlight. So only 10 amps per relay.
Relays come with differing numbers and types of contacts. One possibility is twin contacts so that when relay is switched off power goes through one set of contacts (say to dip) and when switched on it goes through a second set say to main. This would need a relay to switch the power on and off to the main power lines to the relay inputs for the bulbs.
If you are not worried about loosing both headlamps at once then one relay feeding both headlights with a further relay feeding the power to the relay (switched on/off by the headlight switch) would be the simplest.


Dennis

Location: W Devon

What is a dipping headlight!!! (RK)

Location: Stratford upon Avon

My 1933 Austin 10 had N/S and O/S solenoid dipping mechanism,they quite impressed the MOT inspector who had never seen them before, so much so that he ran of into the workshop and dragged the other mechanic out to have a look at them, the poor chap was even more amazed at the wiper motor pull out and twist to start mechanism as well as me adjusting a slight front brake imbalance by lifting out a floorboard and doing the adjustment before he could walk across the MOT bay.

Location: Pembrokeshire

I guess the rarity of explains why no questions about dipping reflectors. The merit is that lamps remain sharp focussed on both settings, very desirable with weak bulbs. Pencil beams were OK on basic narrow roads whereas now need light everywhere to find the far distant edges, lane markings, built out curb edges just in front of car etc.

The reflector dippers can tax skills. There is a heavy current operating solenoid with a low current holding winding. If maladjusted the reflectors vibrate between positions drawing so much current the lamps go dim. With wiring and rubber stops perished a liability.

But to return to the topic. If a dip switch is reckoned capable of the current no need for a relay, avoiding another non standard device, electrical complication, and wasted current. Generous gauge wiring needs to be extended from each filament to the switch, wherever it might be placed. A generous earth wire from the lamps also desirable.

However a relay suits use of the existing switch or switch position with thin wires to.

Location: Auckland, NZ

Paul,
I haven't a relay in the double dipping headlight circuit on my RN saloon. I am pretty certain neither the original dipswitch nor the switchboard on it have been replaced as it has been in my father's possession and then mine for the last 80 years. The dipswitch would have been switching 2 x 24W headlight bulbs which is 8 amps total for the first 70 years of its life before I converted it to 12v. I have just wired my special which has double dipping headlights and as I like to keep things simple I have not put a relay in this circuit.
So that's the route I have taken but if you want to add a relay that's up to you, considering that Stuart and David prefer the extra security to prevent damage to the contacts.
Cheers,
Dave.

Location: Sheffield