Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: drover on October 14, 2016, 12:09:13 pm

Title: electronics advice (not for model boats)
Post by: drover on October 14, 2016, 12:09:13 pm
Totally off topic but I hope someone can help.


My grandchildren enjoy playing with a Micro Scalextric we bought them. They would like a bigger track but Scalextric do not sell extra track for the micro sets. We could move up to the 1/32 scalextric but that takes up more space. I made the mistake of telling them that it is possible to build a custom track and now find myself being asked to make one. Making the track not a problem (other than having to stop working on my models) and I thought wiring up the transformer and controllers would be straightforward, however I had a look at the set-up in the section of power track and met a problem.


My knowledge of electronics is very limited but there seems to be three what I think may be capacitors in the set-up. I believe they may not be essential but help make the cars run smoothly. My problem is there are no markings on these I so I do not know what size of capacitor I would need. The input from the transformer is 19V and the controllers operate on 0-12V.


I tried Maplin's, they were friendly but would not suggest anything, I think they fear being sued if the cars blew up. I'd be grateful for advice. I suppose I could desolder them and transfer to the custom track but I'd rather keep the original track intact.


Thanks in advance for any help

Title: Re: electronics advice (not for model boats)
Post by: unbuiltnautilus on October 14, 2016, 12:21:34 pm
I think they are there to reduce interference from your little Scalextric motors interfering with your TV, I think it is a very 1970s or 80s problem! Something which you will also find inside Hornby Power Feed Clips.
Title: Re: electronics advice (not for model boats)
Post by: nivapilot on October 14, 2016, 12:32:38 pm
bend one back, carefully, and there should be a number on the other side....that will be the ID number.
check on google and you should find a reference for that number which will give an impedance rating.

As posted they are probably for suppression. Not essential, but you may get interference on your Tv or radio.
Title: Re: electronics advice (not for model boats)
Post by: inertia on October 14, 2016, 01:00:22 pm
They are the direct equivalent of those capacitors which many of us fit across the terminals of brushed motors to reduce interference. My bet is that they are either 0.01uF (code 103) or 0.1uF (104). As long as you use disc ceramic types whose voltage rating is above about 25v then either would do. 0.22uF or even 0.47uF would also do the job. These should not be expensive - unless you buy them from Maplin. There are probably suppliers on E-Bay who will sell you ten for a quid including postage.
Dave M
Title: Re: electronics advice (not for model boats)
Post by: drover on October 14, 2016, 01:10:27 pm
I did try looking for numbers last night. The first one had no marking and the others had very faint marks which I thought were scuff marks. However after reading your reply I bent it over again and looked in better light plus a magnifier to discover the very fine marks were indeed the number 104. When I was looking up on the internet everything illustrated seemed to have very obvious markings these were barely legible. Should have gone to Specsavers!


Thanks for the quick responses, the grandchildren especially will be grateful. Grandad was beginning to look like a failure.  I might try without them first (the capacitors that is not the grandchildren) no one will be watching TV while racing anyway! Thanks for the advice about Maplin which appeared just as I was typing.
Title: Re: electronics advice (not for model boats)
Post by: Plastic - RIP on October 14, 2016, 01:34:10 pm
It will almost certainly work without the capacitors but you may get interference on the radio if you are listening at the same time - or your home wi-fi signal may become fritzy while the cars are going down the straights at full speed.

The capacitor values are not too critical - just look on ebay for 100nf ceramic capacitors -

http://www.ebay.co.uk/itm/Nicely-100pcs-bag-Ceramic-Disc-Capacitors-50V-100nF-0-1uF-104pF-UK-EW-/291905317150?hash=item43f6e9a91e:g:TqcAAOSwPhdVH2oo (http://www.ebay.co.uk/itm/Nicely-100pcs-bag-Ceramic-Disc-Capacitors-50V-100nF-0-1uF-104pF-UK-EW-/291905317150?hash=item43f6e9a91e:g:TqcAAOSwPhdVH2oo)

less than 1p each all the way from China!
Title: Re: electronics advice (not for model boats)
Post by: inertia on October 14, 2016, 01:40:32 pm
I found these from a little closer http://www.ebay.co.uk/itm/Ceramic-capacitor-Range-2PF-0-1UF-Rated-50V-High-Quality-Free-Postage-/122171173466?var=&hash=item1c71f82a5a:m:mhCyZTUv3PMGJJPME2793zQ (http://www.ebay.co.uk/itm/Ceramic-capacitor-Range-2PF-0-1UF-Rated-50V-High-Quality-Free-Postage-/122171173466?var=&hash=item1c71f82a5a:m:mhCyZTUv3PMGJJPME2793zQ)
DM
Title: Re: electronics advice (not for model boats)
Post by: dreadnought72 on October 14, 2016, 01:56:59 pm
Another win for the forum!  :-))  A couple of hours to get answers and suppliers' links to the OP.


Mayhem is pretty awesome.


Andy
Title: Re: electronics advice (not for model boats)
Post by: unbuiltnautilus on October 14, 2016, 03:14:24 pm
VERY awesome, not just pretty awesome, surely?
Title: Re: electronics advice (not for model boats)
Post by: NFMike on October 14, 2016, 03:47:55 pm
Bear in mind that while you may not be bothered by it interfering with tv/radio your neighbours may not be as tolerant.
Title: Re: electronics advice (not for model boats)
Post by: drover on October 14, 2016, 04:16:02 pm
I meant I would do a test run while waiting for capacitors to make sure the cars would actually go round the circuit, I'm always doubtful that anything I do will actually work. The rest of the statement was meant to be tongue in cheek. My attempts at humour are clearly as poor as my ability to read small pale numbers!


Have to say I'm very impressed with the help given on this forum, thanks everyone.
Title: Re: electronics advice (not for model boats)
Post by: RAAArtyGunner on October 15, 2016, 02:27:51 am
VERY awesome, not just pretty awesome, surely?

 :o :o :o Yes, Definitely not pretty  %) %) %)