stevenh Posted February 23, 2010 Share Posted February 23, 2010 To all, Can anyone tell me if the Tomix point switches provide momentary power, or perpetually power the points in whichever polarity? I'm currently working out the best method to control these from an Arduino (but the idea would also concern DCC Accessory controllers) and whether or not I should burst out 12v to them or supply a lower consistent voltage. Thanks, Steven. Link to comment
David Posted February 23, 2010 Share Posted February 23, 2010 I think you're talking about the plastic boxes used to control the Tomix switch pieces. I believe they work like the Kato switches (momentary power), just on a slightly lower voltage and with differently shaped connectors. Information in Japanese, including a cut away picture of the Tomix switch controller http://www5a.biglobe.ne.jp/~toyoyasu/ktswitch.htm Link to comment
CaptOblivious Posted February 23, 2010 Share Posted February 23, 2010 They are (rather cleverly designed) momentary switches; leaving the current on permanently would burn out the coil! Your best bet would be to use a capacitive discharge circuit, or at least a small power transistor, since the current draw may exceed what the little Atmel processor can provide. Link to comment
stevenh Posted February 23, 2010 Author Share Posted February 23, 2010 Thanks guys, this is exactly what I didn't want to know :) I think I'll use a H-Bridge and control the voltage (which means I can then reverse it.) That means two sets of points per H-Bridge and therefore six of them for this layout. That'll do, and it's nice and technical :) Link to comment
CaptOblivious Posted February 23, 2010 Share Posted February 23, 2010 You might look at how people have configured the Digitrax turnout decoder for use with Kato turnouts. It is a highly configurable unit, and you could probably glean the current and duration requirements (voltage is 12VDC) from those settings. Tomix turnouts are very very similar to Kato ones, so you could just apply those parameters mutatis mutandis. Link to comment
Fat Al Posted February 24, 2010 Share Posted February 24, 2010 http://www.xs4all.nl/~raicho/model/control/tomixctl/turnout.htm Don't know if this helps, I was just reading this a moment ago... Link to comment
cteno4 Posted February 25, 2010 Share Posted February 25, 2010 Steven, might want to look at the BCD circuit. its a simple capacitor discharge circuit that works great on kato points. we were just getting the coil resistance measurements to figure out the right capicitor for tomix points. nice as it give a much better descrete pulse to activate the coil than any momentary switch would and thus give you the most reliable switch and be nicer on the coils. the kato big blue controller tend to get cranky with age and break. i think the tomix use a very similar momentary contact design as the katos. more info on bcd here http://www.jnsforum.com/index.php/topic,1260.0.html pm me and ill get you the address of the guy to get the plans for it. bout $4 per turnout, but lots of cool options with it. cheers jeff Link to comment
stevenh Posted February 25, 2010 Author Share Posted February 25, 2010 I got it all sorted and working on my Arduino... and then managed to melt the point by switching it perpetually back and forth with a 500ms delay between switching. So, the point motor is still intact, but the point blades are no longer secured. Time to source a non-electrified tomix mini-turnout/switch/point. Link to comment
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