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Post by Curn on May 15, 2020 0:15:23 GMT -5
Got a DP20V2A DC buck power supply which makes a good cheap pure DC power controller. I’m preparing the next generation (Almost age 4). He really wants a blue train (CSX YN3). I’m not quite ready mentally to see an AZL ES44 destroyed. -Matt
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Post by BAZman on May 15, 2020 16:16:03 GMT -5
Oh! I’m going to try that DP202A to replace my 40 year old Lambda Dual Independent 0-30 2A with meters. 2U 1/2 rack and sorta heavy. Very low noise/ripple but that doesn’t count anymore ,) Ordering the color display and the case kit.
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Post by Curn on May 15, 2020 17:23:50 GMT -5
I think my only concern with those power supplies is that it doesn't really have a short protection, but it does have a cut off if the voltage reaches the max it can deliver. So whatever you drive it with, it will drop the output voltage by 2V. So with a 9V battery, the max it will deliver is 7V. And then there is the current max. The power supply will either deliver the set voltage or max current. So if the track gets shorted, it switches to constant current mode and tries to drive the max current, raising the voltage until it hits its max voltage, and shuts off. So if you drop the max current to say 0.5A, it wont raise the voltage high enough to turn off, and you will end up with a melted truck. So the 5A model might actually be better because it will defiantly hit the voltage max trying to push that current. Also you need to add a DPDT switch to reverse the output when needed. The controller doesn't reverse polarity.
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Post by BAZman on May 15, 2020 20:21:27 GMT -5
Yeah, seems like thats what I can deduce out of their lingo. Dang. I don't care so much about going to '0.0' volts (most *nothing* digital will) but the need for ~0-10 (with controlled Current limit - like my Lambda ) BTW: with my Lambda at full CCW Current limit, I get ~5ma, perfect for testing LED's Oh well. I'll look around some more.
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Post by Curn on May 16, 2020 13:00:24 GMT -5
Yeah, I’d like to find a non-PWM small panel mount DC power supply for my MTL F7s. I think I’m just going to have to build one myself, or cobble something together with components. I just need On/Off, voltage regulation, direction control, and overload protection if practical.
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Post by BAZman on May 16, 2020 13:49:37 GMT -5
The LM317 (TO-220 Tab pkg) can easily do it. However, you will never get 0 volts with out a negative supply. The typical schematic has an AC supply to do a half-wave/cap filtered negative and the 317 'ground' thru a diode to that negative.
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on May 16, 2020 14:53:34 GMT -5
OPA547 is better, it allows a current limitation via an unique resistor. Perfect against short circuits, You must only limit the current to the maximum needed by the engine ... Problem : it is a little bit expensive (about 1/2 the cost for an MTL freight car). For myself I use it as an unity-gain voltage follower (Output connected to the inverting input).
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Post by rvn2001 on May 26, 2020 6:02:34 GMT -5
I performed electrical and scenery repairs on a portable layout....and, of course, ran lots of trains.
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Post by ztrack on May 26, 2020 7:26:07 GMT -5
I am jealous.. We were way too busy in the Ztrack offices this weekend. We had five of us working to process orders and keep up with the inbound shipments of products. The only trains running were on our test track. Ann our QC expect was testing running GP38-2s and breaking them in for release.
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Post by cwrr on May 26, 2020 9:02:10 GMT -5
Sounds like Ann has the best job!
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rray
Fireman
Retired and model railroading till the last train out!
Posts: 87
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Post by rray on May 26, 2020 17:43:23 GMT -5
I made progress on my TTZ module: 10 minute overview video:
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Post by cwrr on May 27, 2020 9:13:57 GMT -5
Dang, turned out awesome!!
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Post by Zgauge on May 28, 2020 21:57:30 GMT -5
Not really a weekend update maybe a working for the weekend update thing but it was funny. I was working on a Showcase miniatures building this evening and it has been more challenging than my last Archistories kit so I am struggling a little. I was examining a corner wall assembly that I was finally satisfied with and promptly dropped it into my hot cup of coffee. I laughed took the assembly out of the cup and as the glue was not fully set I pulled it apart wiped it down and reglued.
Then I set it aside, warmed up my coffee and added kahlua.
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Post by Curn on May 28, 2020 22:05:27 GMT -5
Sounds like the coffee wash weathering technique. Similar to an India ink wash.
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Post by rvn2001 on Jun 7, 2020 20:33:30 GMT -5
I finished a project that I've had around the house for several years. I built one of these for Ellen Shelton who lives in Indiana. I had the decals and the painted body for a second one laying around waiting to be completed. It is now complete and operational.
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