Simon, You like me did not benefit from a close association with BTH, my father worked in the Neasden, Harlesden, Willesden area in the heavy switchgear dept, had I known what I do know I would have asked if he could enquired about getting some of those nice BTH magnetos, especially one of those KVF TT equivalents.
B.T.H Magneto-Generator Series 'A' Comet
- Thread starter Michel
- Start date
Ah, job for life - those were the days. I ended up having three careers and a profession when I'd have been happy to stay with my first employer, just for the job satisfaction.
OK, I'm going to be away for a few days........ AEI (Associated Electrical Industries) was BT-H's parent Co back in the day. I'm told at some point they had a corporate idea to change all their product lines to AEI with the result that sales dropped like the proverbial stone because no one knew the brand. All rather quickly changed back. I understand that a certain UK Rebuilder bought a barrel full of AEI mags quite a few years ago, which got refurbished and sold. I tried to buy some bits from him a couple of years ago for a Lucas mag-dyno and was refused, as "we don't ship to America". I told them I would just get one of my UK friends to buy the bits to which I was told that they would not sell those particular bits to anyone if they even got an inkling they were coming across the pond. I pointed out that Canada was not generally considered to be America, as in the United States of, but was told it's all the same to them...... Sad really. Just don't tell him I have one of his AEI mags!
I meant to post this last night but missed the post reply button, so a bit out of context.
I worked for English electric ,metal industries,and a whole plethora of companies without changing my job Arnold Wienstock I think was the MD at the end an asset stripper that made the BSA Dockers look angelic
Thank you all for those explanations.
On my Serie A, the headlight switch shows "DIM", "OFF and "FULL. What that means "DIM" ?
If I yes understand:
When the bike is on the parking , the cutout and the headlight switch are "OFF" (or "DIM" ?) to avoid the battery to empty into the dynamo.
When riding the motorcycle , the cutout must be "ON". And for the headlight switch , "DIM", "OFF" or "FULL" it as required (again, what means "DIM" ?).
For now I will place a fuse between the battery and the generator , how many amp fuse ?
What's aspect of the original cutout (Miller ? ) fixed on the toolbox . ? Do you have a picture of this cutout ? Does exist replica ?
Thanks again.
On my Serie A, the headlight switch shows "DIM", "OFF and "FULL. What that means "DIM" ?
If I yes understand:
When the bike is on the parking , the cutout and the headlight switch are "OFF" (or "DIM" ?) to avoid the battery to empty into the dynamo.
When riding the motorcycle , the cutout must be "ON". And for the headlight switch , "DIM", "OFF" or "FULL" it as required (again, what means "DIM" ?).
For now I will place a fuse between the battery and the generator , how many amp fuse ?
What's aspect of the original cutout (Miller ? ) fixed on the toolbox . ? Do you have a picture of this cutout ? Does exist replica ?
Thanks again.
I put in ( stupidly but it was a test) a 12 volt fuse steatite . No more load because the resistance of the fuse is probably too high for the low charge of the BTH .
I have found a 6-volt switch with minimal resistance ( ohms minimum ) . Do you know a supplier?
I have found a 6-volt switch with minimal resistance ( ohms minimum ) . Do you know a supplier?
Michel
Just been taking some photos of my bike for you. Is this the BTH mag / dyno you have?
If so the original BTH (not Miller) cutout fitted on top of the toolbox. Here is a picture of mine. You can just see the circle in the top that shows the BTH symbol. The cutout can be replaced by a diode rated at 10A to 15A. The original BTH cutouts are extreamly difficult to find and I don't know of any replicas been made. The cutoput just stops the battery discharging back through the dynamo when the dynamo is not generating.
The orignal Miller headlight switch has 4 positions. Off, Ch, H, L. When used with the BTH dynamo, Off, disconnects the dynamo from the battery. Ch connects the dynamo to the battery through a resistor to limit the charge rate. H switches the headlight on and bypasses the charge resistor to allow maximum charge. L switches the side light on if fitted. The 3 position switch you have is a aftermarket copy which was never used on Vincent's and so will not work for this charging system as it is. There are replica 4 position switches available, I think the VOC spares sell them, but these only have four contact positions on the back which is what series B & C used. The switch you need has seven contacts on the back to allow for switching the charge resistor. You may have to find an original.
There is a possible alternative. Brian Werrett (in UK) has just completed restoring the Model PS for the club and was shown on the front of June's MPH. This bike also has a BTH with the cutout. Brian is thinking of getting an electronic regulator made by a company which will act as the cutout and also regulate the dynamo output so no charge resistor or switch in the Off or charge position will be required. This regulator will automatically work like the later bikes did, but it will only work on this type of BTH mag dynamo. If you send me your email address in a private message through the forum, I will forward it to Brian.
Regards
Simon
VOC Machine Registrar
Just been taking some photos of my bike for you. Is this the BTH mag / dyno you have?
If so the original BTH (not Miller) cutout fitted on top of the toolbox. Here is a picture of mine. You can just see the circle in the top that shows the BTH symbol. The cutout can be replaced by a diode rated at 10A to 15A. The original BTH cutouts are extreamly difficult to find and I don't know of any replicas been made. The cutoput just stops the battery discharging back through the dynamo when the dynamo is not generating.
The orignal Miller headlight switch has 4 positions. Off, Ch, H, L. When used with the BTH dynamo, Off, disconnects the dynamo from the battery. Ch connects the dynamo to the battery through a resistor to limit the charge rate. H switches the headlight on and bypasses the charge resistor to allow maximum charge. L switches the side light on if fitted. The 3 position switch you have is a aftermarket copy which was never used on Vincent's and so will not work for this charging system as it is. There are replica 4 position switches available, I think the VOC spares sell them, but these only have four contact positions on the back which is what series B & C used. The switch you need has seven contacts on the back to allow for switching the charge resistor. You may have to find an original.
There is a possible alternative. Brian Werrett (in UK) has just completed restoring the Model PS for the club and was shown on the front of June's MPH. This bike also has a BTH with the cutout. Brian is thinking of getting an electronic regulator made by a company which will act as the cutout and also regulate the dynamo output so no charge resistor or switch in the Off or charge position will be required. This regulator will automatically work like the later bikes did, but it will only work on this type of BTH mag dynamo. If you send me your email address in a private message through the forum, I will forward it to Brian.
Regards
Simon
VOC Machine Registrar
Can you clarify what this is?