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I want to run side lites (6) and head lite on a MTH PS1 Dreyfus Hudson upgraded to PS2/3 off of the headlite circuit by using a miniature relay, in place of the CV Board.  Headlite circuit will provide power to energize and control the relay. 

I heed advice regarding relay specs and possible sources of such a relay.

Thanks.

 

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Not sure I understand what you're asking.  As I understand it, the CV board is taken out of the picture.

So the PS3/2 H/L circuit turns on a relay.  What does the relay then switch to turn on the 6 side lights and presumably the H/L bulb too?  What are these 6 side lights (LEDs, 6V bulbs, something else)?

Why can't you just drive the headlight bulb with the PS3/2 H/L circuit and add the 6 side-lights in parallel with the H/L bulb - subject to the power limitations of the H/L circuit - hence the question about what these side lights are...

 

 

The headlight circuit uses a similar FET as the PS/2 boards, and is capable of at least 1/2 amp or more of power.  If you limit the side lights and headlight to less than 500ma, you should be able to run them all from the headlight output.  The limitation is probably the PV current available, here's the rating of the PS/2 3V board LED.  I'd probably take the 1.7A continuous rating with a slight grain of salt, but it's clear that the little guy shouldn't have much of a problem with seven of the normal MTH 60ma bulbs.

fet

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John,  I do not think so.  The MTH bulbs are 60ma and MTH never uses more than 3 on a circuit.   I would not load 7 or 8 bulbs on to a SMD FET despite that rating.

There is an old article on how to do this.  You use the headlight FET to turn relay on and off.  You use Track power and chassis ground to power the bulbs (18V Bulbs) and the relay is the switch.   OR you keep CV in and use the relay to turn track power on and off to the CV board.  Hence gain control of all lighting via PS-2 and do not have to change bulbs or marker.  Or if willing you can run another control line over separate from 10 pin and gain additional light or coupler control.   G

I have seen four in one George, the two number boards and two cab lights.  I agree, that's not 7 bulbs, but then we don't know the current rating of the bulbs. 

You can obviously use a relay, a 5V coil relay with a small cap to reduce chatter would do the trick.  With the relay, I would also use track power to eliminate any additional load on the PV.

FWIW, I use similarly rated FET parts on my Super-Chuffer and Chuff-Generator, and I've personally tested them with a 1/2 amp load without any issue of overheating.  With a bad fan motor, the Super-Chuffer fan FET is actually able to shutdown the 1/2 amp switching P/S module without killing the FET, they will handle quite a bit of current.  Of course, the PCB traces may be an issue as well if you put too much of a load on the PS/2 board FET outputs...

This can be done using a relay activated by the headlight to direct track power to the CV board to operate the lights.  I have seen this come through my shop in the past.  I did not write down the number on the relay.

John N, you can use LEDs for the headlight, driver lights, fire box and run them all off of the headlight.  There is enough power there.

Dave

Casey Jones2 posted:

I've used these in the past with PS2 boards.

http://www.digikey.com/product...61B/CC1061-ND/139580

YIKES!  $25???

Let's come down to reality and go with something affordable.  Also, you can't use the solid state relay with track power if it's not 100% isolated.  It's also specified for DC control only.

http://www.digikey.com/product...TS/PB1094-ND/1633980 is $3.51 quantity one.

 

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