Of course; I am rather too sloppy with my terminology.
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My shopping list for the diode ladder seems cheap enough. Probably will buy those. Wire it up. Check it outâŚThen build my mock up throttle notch control for the âfront endâ of this DIY project. Thanks to all for the pointers. regards mike endmrw0522261818
Sounds goodâjust make sure that your diodes have (more than) enough amperage. I know that itâs assuredly overkill for HO like you use, but these 10-amp diodes are pretty effective: 50PCS/LOT 10A10 10 Amp 1000V 10A 1KV Axial Rectifier Diode 22A: Amazon.com: Industrial & Scientific
Iâm actually working on a similar project for my own railroad, and even designing a commercially viable diode-based throttle!
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I keep thinking of a Sony hi-fi âimprovementâ in the 1970s to implement an accurate âsmoothâ volume control with low inductance. This was done by printing a large number of thin radial âsectorsâ on a PCB, with a wiper contact pivoted at the center like a needle in a Panelescent dashboard gauge, and the equivalent of a resistance ladder joining the outer edges of the segments (this could be done with laser-trimmed resistive paint or material).
With custom PCBs now being cheap and quick to order, a version with heavy copper arranged as the diode-ladder contacts night be a cost-effective way to produce a ânotchâ controllerâŚ
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Thatâs very similar to my idea for the commercial version. The idea gets even more attractive when you take into account the fact that I intend to construct a CNC router to mill out PCBs! For my little private one, I just bought a cheap 12-position rotary switch (some positions will be unused for my 8-notch throttle) and a whole bag of diodes.
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Hi
Seems I missed one of your questions. I will be using 2 ZW transformers to run a 3 train layout plus all accessories including lights etc. I am hoping my plan works otherwise I am back to square one. Donât have room for 10 plus transformers, barely have room for the 2
ZWs, but that is another story
Take care,
Bill
Okay, Bob an associated question on my âwild dreamâ of âslow accelerationâ of loco.
Remember that was to be accomplished via a huge capacitor (Iâm told used in audio equipment). For WHAT? Value = 500K microfarads. Itâs no small item.
Works great to have slow acceleration even when notch 8 and full voltage is sent to the track circuit. The capacitor takes so long to charge = slow rise = slow acceleration.
A PLUS, drop to notch 1 and the capacitor has to discharge the voltage, that causes the loco to coast. I will install a circuit to short the capacitor = dumping air for emergency.
In both cases it is the resistance that will determine the rate of charge or discharge. Remember that you cannot smoothly regulate this with a diode ladder; you need a ârate adjustmentâ to charge the capacitor to regulate voltage gain and hence acceleration rate, and a second for discharge/âmomentumâ rate. (For additional realism you could arrange a deceleration rate that changes stepwise by âsetsâ and then emergency on an air-brake control handleâŚ)
With any large capacitor, whether in LC âsmoothingâ of rectified DC voltage or in audio uses â remember to rig a few megohms as a bleeder across the cap instead of âshortingâ to discharge it for safety. The ASPCT has policies against endangering common metal tools when discharging any capacitor that can hold substantial chargeâŚ
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