Hi;As usual, I have an off the wall question that most of you probably haven't run into. I have 2 DAC20 DCC Accessory decoders for 8 turnouts each (made by CML Electronics in the UK) and am at my wits end trying to get them to work with Kato turnouts. I have built the little circuits CML shows on their website that reverse polarity for the Kato solenoids. I have also been in contact with Laurence Baker of CML Electronics and he has been very helpful in getting the CVs set correctly, using the LocoBuffer USB etc. If you have used these DAC10s or 20s with Kato turnouts, I would love to hear from you. I supect something may be wrong with the little circuits I built up, but I know enough about electronics to be dangerous and am not sure how to check them.Thanks in advance,Tom Mann.
I don't have any, but I looked over the circuit, if wired EXACTLY as shown it should work fine. Did you use the exact specified components, or did you make subsitutions? One thing to watch on some transistors, the center lead is not always the base, so while the schematic shows the wires in traditional schematic order, that may NOT match the actual wires coming out of the transistor. Carefully recheck the wiring on your circuits - I suspect this is probably where you went wrong.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy;
Thanks, if you look at the data sheets for th 2N4403, the Emitter can wither be pin 1 or pin 3 depending on the manufacturer. Since I have no idea who made these, I'll try reversing the transistors and see if that works. (They all seem to have pin 2 as the Base.)
Tom Mann.
I checked some datasheets - wow. That's quite unusual, normally there is a standard pin arrangement based on the flat side or else a small mark. But half of the TO-92 ones have the emitter on the left with the flat facing you and half have the collector on the left. Normally one way is a PNP and the other is an NPN. Hopefully that's all it is, there's nothign else in that circuit but the bias resistors. I'll assume the CVs are all set properly since you were working directly with Laurence. Great thing about some of these smaller companies - you can talk to the people who actually designed the things.