For Mr Beeny Boy when he decides to sober up, and get out of bed. 😁

Snubbers or RC filters.

I’ve a little project I need to do on the trainset.

I think I may be getting noise on the AC track bus that powers the train track. ~15 V AC power.

The longer the bus (power rail some call it I think), the more noise on the edges of the AC phase switch “edge” (is it called?) (voltage spikes can occur).

I’m yet to put the silly scope on the end of the bus to prove this.

This interferes with the command signals that get sent to each train motor, that are slotted between the AC phase switch. The interference can cause the decoder in each loco to ignore the commands, or think it’s a DC voltage, stop the loco, resets, and takes off again.

The interference can be caused by a number of things, including micro shorts, or arcing between the loco wheels and the track, going across points, or diamond crossings etc, among other things.

I understand the use of “snubbers” can sort this out.

A basic “snubber” consists of a capacitor and resistor.

I’ve specs to use a:

Resistor 100 ohm 1/2 watt
Ceramic disc capacitor 0.1 uF 50VDC ( to manage edge spikes up to ~35V) The little yellow disc ones.

Now………………….. Jaycar does not list “Ceramic disc capacitor 0.1 uF 50VDC “

However they do have these:

0.1uF 50V Blue Chip Monolythic Capacitor – Pk.100

here

Will they do the same thing?

Taa muchly Mr Beeny Boy.

You can go back to bed now. 😊

probably do for what you want

transition said:

probably do for what you want

capacitors look a bit more like this below, you want C/capacitance, but you get a little L/inductance and R/resistance with it, depending on type of capacitor, size of capacitor, and lead length contributes also, which starts to matter as frequency gets high, very high, probably higher than you need bother about

of course the reality of X/reactance is more complex that, i’ve dumbed it down so I can pretend to understand it

Sorry, Woodie, just back from Pambula. Was helping one of my sisters move. Muggy as all fuck it was, and as I can get up a decent sweat in an igloo I was drenched.

As to your question about the Monolythic Capacitor – yep, use away – it is just a variation on a standard ceramic package.

As to the the resistor, 1/2 watt is probably overkill. I’d just go with a standard 1/4 watt jobby.

sibeen said:

Sorry, Woodie, just back from Pambula. Was helping one of my sisters move. Muggy as all fuck it was, and as I can get up a decent sweat in an igloo I was drenched.

As to your question about the Monolythic Capacitor – yep, use away – it is just a variation on a standard ceramic package.

As to the the resistor, 1/2 watt is probably overkill. I’d just go with a standard 1/4 watt jobby.

Taa muchly Mr Beeny Boy. 😁

Having said that, I was going to up it to a 1 watt resistor. Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

Wadda ya reckon?

Woodie said:

sibeen said:

Sorry, Woodie, just back from Pambula. Was helping one of my sisters move. Muggy as all fuck it was, and as I can get up a decent sweat in an igloo I was drenched.

As to your question about the Monolythic Capacitor – yep, use away – it is just a variation on a standard ceramic package.

As to the the resistor, 1/2 watt is probably overkill. I’d just go with a standard 1/4 watt jobby.

Taa muchly Mr Beeny Boy. 😁

Having said that, I was going to up it to a 1 watt resistor. Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

Wadda ya reckon?

Yeah, but if the snubber is drawing more than a few milliamps I’d be surprised.

sibeen said:

Woodie said:

sibeen said:

Sorry, Woodie, just back from Pambula. Was helping one of my sisters move. Muggy as all fuck it was, and as I can get up a decent sweat in an igloo I was drenched.

As to your question about the Monolythic Capacitor – yep, use away – it is just a variation on a standard ceramic package.

As to the the resistor, 1/2 watt is probably overkill. I’d just go with a standard 1/4 watt jobby.

Taa muchly Mr Beeny Boy. 😁

Having said that, I was going to up it to a 1 watt resistor. Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

Wadda ya reckon?

Yeah, but if the snubber is drawing more than a few milliamps I’d be surprised.

Kewlies. I’ll stay with your recommended.

Anyways, I’m gunna put me silly scope on it all and prove that I’ve got the problem I think I have.

I’ll keep you informed. 😁

> Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

That’s a lot just for trains. Why so high?

mollwollfumble said:

> Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

That’s a lot just for trains. Why so high?

This ain’t no kid’s “kept under the bed” trainset, Mr Fumble.

Some reading for you.

https://dccwiki.com/DCC_Power

Woodie said:

mollwollfumble said:

> Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

That’s a lot just for trains. Why so high?

This ain’t no kid’s “kept under the bed” trainset, Mr Fumble.

Some reading for you.

https://dccwiki.com/DCC_Power

I like that reading.

Is that switching applied on top of a fixed high frequency using phase modulation or amplitude modulation? I once worked out a system to use both phase modulation and amplitude modulation together.

Oh, I see, neither. “It is not superimposed on a DC or AC waveform, nor does it use a high frequency carrier, unlike past and current command control systems.” My system was a digital signal superimposed on a high frequency AC carrier, in my case the AC carrier was visible light.

> The nature of a square wave results in more demanding requirements for wiring to avoid voltage losses and signal distortion compared to analog control methods.

So it’s not wireless then? If it was wireless then this signal, being a square wave, would have a very strong loss of signal strength with distance. But I suppose that would be alright in your case, too, because the signal wouldn’t have to travel far. (My application was for long distance optical fibre multiplexed digital signal transmission).

> The data is encoded in the time domain … The amplification is performed by two pairs of transistors functioning as switches.

No problem there.

> For N scale, the amount of power needed is low, from 36 to 60 Watts. For HO it can range from 50 to 80W. With larger current boosters, HO can reach 125W, and with larger scales, 240W.

Checks web.

mollwollfumble said:

Woodie said:

mollwollfumble said:

> Cause if I’ve got a lot of locos on the track, it can draw 3 – 5 amps.

That’s a lot just for trains. Why so high?

This ain’t no kid’s “kept under the bed” trainset, Mr Fumble.

Some reading for you.

https://dccwiki.com/DCC_Power

I like that reading.

Is that switching applied on top of a fixed high frequency using phase modulation or amplitude modulation? I once worked out a system to use both phase modulation and amplitude modulation together.

Oh, I see, neither. “It is not superimposed on a DC or AC waveform, nor does it use a high frequency carrier, unlike past and current command control systems.” My system was a digital signal superimposed on a high frequency AC carrier, in my case the AC carrier was visible light.

> The nature of a square wave results in more demanding requirements for wiring to avoid voltage losses and signal distortion compared to analog control methods.

So it’s not wireless then? If it was wireless then this signal, being a square wave, would have a very strong loss of signal strength with distance. But I suppose that would be alright in your case, too, because the signal wouldn’t have to travel far. (My application was for long distance optical fibre multiplexed digital signal transmission).

> The data is encoded in the time domain … The amplification is performed by two pairs of transistors functioning as switches.

No problem there.

> For N scale, the amount of power needed is low, from 36 to 60 Watts. For HO it can range from 50 to 80W. With larger current boosters, HO can reach 125W, and with larger scales, 240W.

Checks web.

All a bit different now, Mr Fumble, since winding up the spring, putting it on the track, and WHIIIZZZZZZZZ round a cuppla times and repeat. 🚂🚂🚂

Woodie said:

All a bit different now, Mr Fumble, since winding up the spring, putting it on the track, and WHIIIZZZZZZZZ round a cuppla times and repeat. 🚂🚂🚂

LOL.

Dear Mr Beeny Boy,

A quick question.

I’ve got my silly scope out, and if you recall, it does 12V.

I need to to show up to 50V (spikes)

I can switch each channel to 1:10. This should do it?

But do I need a 1:10 probe as well? I think I do.

I’ll nee to make one, methinks.

Researching AWS.

Does me research

There’s this one, which seems nice and simple.

https://cromwell-intl.com/radio/probes.html

and this one, which is more complicated, and quite different from the other one.

https://www.youtube.com/watch?v=NxNChfFzAFM (2 mins)

Or will a 10K ohm resistor on it’s own suffice?

NB: I just run two separate probes. Ch1 & GRD. No resistors at all.

Woodie said:

Does me research

There’s this one, which seems nice and simple.

https://cromwell-intl.com/radio/probes.html

and this one, which is more complicated, and quite different from the other one.

https://www.youtube.com/watch?v=NxNChfFzAFM (2 mins)

Or will a 10K ohm resistor on it’s own suffice?

NB: I just run two separate probes. Ch1 & GRD. No resistors at all.

Well it’s useless anyway.

Peak Warming Man said:

Woodie said:

Does me research

There’s this one, which seems nice and simple.

https://cromwell-intl.com/radio/probes.html

and this one, which is more complicated, and quite different from the other one.

https://www.youtube.com/watch?v=NxNChfFzAFM (2 mins)

Or will a 10K ohm resistor on it’s own suffice?

NB: I just run two separate probes. Ch1 & GRD. No resistors at all.

Well it’s useless anyway.

I see what you did there…

Peak Warming Man said:

Woodie said:

Does me research

There’s this one, which seems nice and simple.

https://cromwell-intl.com/radio/probes.html

and this one, which is more complicated, and quite different from the other one.

https://www.youtube.com/watch?v=NxNChfFzAFM (2 mins)

Or will a 10K ohm resistor on it’s own suffice?

NB: I just run two separate probes. Ch1 & GRD. No resistors at all.

Well it’s useless anyway.

bump for Mr Beeny Boy.

Woodie said:

Dear Mr Beeny Boy,

A quick question.

I’ve got my silly scope out, and if you recall, it does 12V.

I need to to show up to 50V (spikes)

I can switch each channel to 1:10. This should do it?

But do I need a 1:10 probe as well? I think I do.

I’ll nee to make one, methinks.

Researching AWS.

bump

This one too.

Woodie said:

Woodie said:

Dear Mr Beeny Boy,

A quick question.

I’ve got my silly scope out, and if you recall, it does 12V.

I need to to show up to 50V (spikes)

I can switch each channel to 1:10. This should do it?

But do I need a 1:10 probe as well? I think I do.

I’ll nee to make one, methinks.

Researching AWS.

bump

This one too.

Yes, you do need a 10:1 probe as well. In fact CROs work far better with a 10:1 probe for higher bandwitdth measurements. An oscilloscope probe uses a special type of high resistance metal.

I’ll look at the rest in a day or two. I am quite pissed at the moment and have a 7 hour drive on he morrow, followed by my godson’s 21st, so Sunday is out, etc etc :)

sibeen said:

Woodie said:

Woodie said:

Dear Mr Beeny Boy,

A quick question.

I’ve got my silly scope out, and if you recall, it does 12V.

I need to to show up to 50V (spikes)

I can switch each channel to 1:10. This should do it?

But do I need a 1:10 probe as well? I think I do.

I’ll nee to make one, methinks.

Researching AWS.

bump

This one too.

Yes, you do need a 10:1 probe as well. In fact CROs work far better with a 10:1 probe for higher bandwitdth measurements. An oscilloscope probe uses a special type of high resistance metal.

I’ll look at the rest in a day or two. I am quite pissed at the moment and have a 7 hour drive on he morrow, followed by my godson’s 21st, so Sunday is out, etc etc :)

CRO = Cathode Ray Oscilloscope?

Mine’s $40 kit put together by me, and plugs into the USB port of my laptop.

It’s nuttin to high falootin’, hey what but.

bump for Mr Beeny Boy.

You forgot didn’t ya!!! Come on…….. On ya knees and beg for forgiveness.

taps foot and ponders

OK. You’re forgiven.

I took the easy way out and went for these,

https://www.ebay.com.au/itm/313757500042

Can’t go wrong really. 😁

Woodie said:

bump for Mr Beeny Boy.

You forgot didn’t ya!!! Come on…….. On ya knees and beg for forgiveness.

taps foot and ponders

OK. You’re forgiven.

I took the easy way out and went for these,

https://www.ebay.com.au/itm/313757500042

Can’t go wrong really. 😁

For the bandwidth that you are looking at these will be the grouse :)

sibeen said:

Woodie said:

bump for Mr Beeny Boy.

You forgot didn’t ya!!! Come on…….. On ya knees and beg for forgiveness.

taps foot and ponders

OK. You’re forgiven.

I took the easy way out and went for these,

https://www.ebay.com.au/itm/313757500042

Can’t go wrong really. 😁

For the bandwidth that you are looking at these will be the grouse :)

Just make sure you use them on the x10 setting.

sibeen said:

sibeen said:

Woodie said:

bump for Mr Beeny Boy.

You forgot didn’t ya!!! Come on…….. On ya knees and beg for forgiveness.

taps foot and ponders

OK. You’re forgiven.

I took the easy way out and went for these,

https://www.ebay.com.au/itm/313757500042

Can’t go wrong really. 😁

For the bandwidth that you are looking at these will be the grouse :)

Just make sure you use them on the x10 setting.

Had to get some male BNC chassis/panel connectors as well. I really should put the whole thing in a case.

All just ordered off Ebay and on their way. 😁