Electronic problem. Help needed,please.

[powlee]

[banghead]Folks,
I need the benefit of your electrical skills. I transferred my Phoenix Sound system out of a loco and fitted it into a boxcar. Easy job, sounds great BUT.

I run my trains with a Train Engineer and had a spare 5474 receiver and read somewhere that they would fit in a trailer and control the sounds with a touch of button. All connected and working when I noticed said receiver smoking when placed on the track. Rescued it and realised maximum voltage is 16 volt when track gives off a lot more. My other static receivers run on 12 volts so had not experieced problem when building it on the bench.

How can I reduce the voltage inside the boxcar. I know there is probably an easy solution so please quench my thirst for knowledge so I can carry on with this project.[D)]

Please help

Ian P

[Anonymous]

There has got to be a better method than this, but...
A diode will drop 1.2v each. So if you connect 4 of them together in a line (in series) you should drop 4.8v which will be enough for you to carry on testing until someone gives you a better idea.
Obviously a diode only lets power through in one direction, so you will need to be careful which way round they face. If there is no power, then one or more of them are the wrong direction.

Glen.

[grandpopswalt]

Glen,

If I understand correctly, you've got a device rated 16 volts max and your track power is considerabley greater. You can use diodes in series which will drop about .6 volts each. So if you have 24 volts track power you need to drop (24 - 16 = 8 volts. 8/.6= 13.3 diodes. you'd use 14 diodes to drop 8.4 volts. If the track power reverses polarity, you'd use a bridge rectifier ahead of the dropping diodes and would then have constant polarity applied to your device. A better way is to use a voltage regulator (available for a couple bucks at any Radio Shack). The wiring is very simple and is printed right on the blister-pack card. The advantage is that the component count is much lower as compared to doing it with diodes.

If you really get involved with this, e-mail me and I'd be happy to work with you off-forum.

Walt

[powlee]

Walt
It`s actually me asking the question. My problem was I believed everything I read. On the Aristo website, it states that that the 5474 can be fitted as such but forgets that the averge garden railroad runs 20-24V. I naively thought it would be safe.
The voltage regulator seems the ideal situation. I will try my local electronics shop. And thanks also Glen.

Ian P

[Anonymous]

Try here Ian.Buy online,next day delivery.I use them all the time.
www.maplin.co.uk

[powlee]

QUOTE: Originally posted by troybetts

Try here Ian.Buy online,next day delivery.I use them all the time.
www.maplin.co.uk

Thanks Troy
I was in our local one last week buying other stuff. Did not know at the time I would have another problem. Off to Hounslow after the Bank Holiday

All the best

Ian

[Anonymous]

Ian;

I had the same trouble with my signals and lighted prellbock i bought in ebay and did it with ohms law. a 350 ohm 1 -2 watt resistor did the job very nicley.


Rgds Ian

[grandpopswalt]

Got to be careful using resistors. If the current draw changes, then the amount of voltage dropped on the resistors will vary proportionally.

Walt