DIY Power buffer
- Thread starter ge_rik
- Start date
Neil Robinson
Registered
I think you could omit one of the capacitors from Greg's circuit if you really needed to at the expense of only having a buffer for one direction. If, for example, you had a steam outline loco that invariably ran chimney first then this could be O.K. It would still be able to run backwards but without any buffering. However I have a nagging doubt that I've forgotten something important so I suggest getting at least one other opinion and/or experimenting before fitting to a loco.ge_rik said:
gregh
electronics, computers and scratchbuilding
From my memory back in Uni days, you can use just the 2 capacitors on AC - ie as in a speaker crossover. But when you have DC voltages across them for long periods, you put the diodes in to protect the electrolyte. I'm not sure of the exact reasons, but diodes are a cheap safety measure.ge_rik said:
PUT THE DIODES IN!
Who is to say 'someone' won't put a steam outline tender-first, and run it for quite some time?
Picking up all those bits of silver paper etc. when a capacitor goes bang from wrong polarity takes AAGGEESS!
A few pence for a couple of diodes is not worth the risk.
Phil.
Who is to say 'someone' won't put a steam outline tender-first, and run it for quite some time?
Picking up all those bits of silver paper etc. when a capacitor goes bang from wrong polarity takes AAGGEESS!
A few pence for a couple of diodes is not worth the risk.
Phil.
ge_rik
British narrow gauge (esp. Southwold and W&LLR)
Hi
I'm going to have a go at adding my own power buffer to one of my locos using the info on the Massoth forum
http://forum.massoth.org/viewtopic.php?t=216
Can someone with more electronical knowledge than me advise - will a 1W rated 150R resistor be OK or should I go for a 2W rated one? The one used in the picture on the forum looks like a lower rated one to me.
Rik
I'm going to have a go at adding my own power buffer to one of my locos using the info on the Massoth forum
http://forum.massoth.org/viewtopic.php?t=216
Can someone with more electronical knowledge than me advise - will a 1W rated 150R resistor be OK or should I go for a 2W rated one? The one used in the picture on the forum looks like a lower rated one to me.
Rik
ntpntpntp
Registered
If I remember correctly (it's been at least 3 decades since I studied electronics and stuff): Very roughly if we assume voltage = 25V and we know the resistance is 150R, therefore peak watts is given by V(squared)/R = 25 x 25 / 150 = 4 watts ish. This will drop off quite rapidly as the capacitor charges and the voltage across the resistor drops. There are formulae and pretty graphs around if you want to check the curves for resistor/capacitor circuits, but I reckon a 1 watt resistor is probably ok.
shropshire lad
Registered
Excellent thread, ordered some bits to make some up for my ICE train.
ge_rik
British narrow gauge (esp. Southwold and W&LLR)
Hi
Just fitted a DIY power buffer to one of my most unreliable locos which used to stumble at virtually every frog it encountered - a 2-4-0 GRS kit with an 0-4-0 motor block.
Very pleased with the results:
video=http://www.youtube.com/watch?v=RcUf8-bD4es&feature=youtu.be
Total cost = £2.33 (not including a small amount of solder and a couple of short pieces of wire)
I've posted a step-by-step guide on my blog if you fancy having a go yourself.
http://riksrailway.blogspot.com/2013/07/how-i-fitted-my-own-dcc-power-buffers.html < Link To http://riksrailway.blogsp...dcc-power-buffers.html
Rik
Just fitted a DIY power buffer to one of my most unreliable locos which used to stumble at virtually every frog it encountered - a 2-4-0 GRS kit with an 0-4-0 motor block.
Very pleased with the results:
video=http://www.youtube.com/watch?v=RcUf8-bD4es&feature=youtu.be
Total cost = £2.33 (not including a small amount of solder and a couple of short pieces of wire)
I've posted a step-by-step guide on my blog if you fancy having a go yourself.
http://riksrailway.blogspot.com/2013/07/how-i-fitted-my-own-dcc-power-buffers.html < Link To http://riksrailway.blogsp...dcc-power-buffers.html
Rik
Zerogee
Clencher's Bogleman
Brilliantly simple and effective job, Rik, and a great blog post and video how-to! Very tempted to try one myself.
It's small enough to even fit in a Feldbahn loco - though in that case, does anyone know how to get to the Decoder + and Decoder - terminals on a Massoth M/ LGB 55022.....? I fear that bit of soldering might be beyond me, though I could manage the making up of the buffer.
By the way, did you ever download the English translation for that latest Voie Libre issue and read the original article that started you off on this thread?
Jon.
It's small enough to even fit in a Feldbahn loco - though in that case, does anyone know how to get to the Decoder + and Decoder - terminals on a Massoth M/ LGB 55022.....? I fear that bit of soldering might be beyond me, though I could manage the making up of the buffer.
By the way, did you ever download the English translation for that latest Voie Libre issue and read the original article that started you off on this thread?
Jon.
whatlep
Registered
JonZerogee said:
PM me with a real email address and I'll send you a scan of the German magazine which published illustrations of how to connect a buffer to reach LGB decoder type. The 55021 (or 55020) is easy - you can even attach wires directly to spare pins on the decoder if it's pushed into a direct decoder interface, but the 55022 looks like one for a specialist like Gizzy.
Zerogee
Clencher's Bogleman
Actually, Peter, do you happen to know the magazine title and issue that your scan is from? Recently I've managed to acquire almost complete sets of Gartenbahn, Gartenbahn Profi, Volldampf and SPUR G covering most of the last few years, so there is a good chance I may already have the issue in question!
Jon.
Jon.
Zerogee
Clencher's Bogleman
whatlep said:Zerogee said:
Volldampf, February 2012. Pages 46/47.
Thanks Peter - got the scan from you, I'm pretty sure I have that issue though, will have to search through the big pile of them!
I've skimmed through most of the issues since I got them, and I now vaguely remember seeing that article.
Of course, the advantage of using the scan you sent is that I can copy and paste the text into Google Translate.
Looks like the fitting to a 55022/Massoth M is a tricky bit of soldering, as expected - may well be calling on you, Gizzy!
Just an aside, re disconnecting the buffer in order to program CVs - the sound-chipped-and-buffered Harzkamel that I bought from Germany recently had a neat little addition by the guy who converted it - he fitted one of those little single-pole plug and inline sockets, like the old round LGB lighting plugs, into the buffer wire and tucked this connector just behind one bufferbeam of the loco, on a few cm of extra cable - thus it's easy to pull the plug and socket out, disconnect it to do the programming, then connect up and tuck it away again. It's the sort of little trick that is well worth planning into your installation, saves trying to mount a switch somewhere or having to take the body off every time you want to alter a CV.....
Best,
Jon.
ge_rik
British narrow gauge (esp. Southwold and W&LLR)
A quick question to the electronics boffins out there.
After more extensive trials I have discovered there is still one point on my railway where, even with the buffer, the loco sometimes stalls if I go over it very very slowly. If I wired another 2200uF capacitor in parallel with the original, would I double the duration of the discharge, or would I need to replicate the existing circuit, or what?
Rik
After more extensive trials I have discovered there is still one point on my railway where, even with the buffer, the loco sometimes stalls if I go over it very very slowly. If I wired another 2200uF capacitor in parallel with the original, would I double the duration of the discharge, or would I need to replicate the existing circuit, or what?
Rik