Live frog vs dead frog - pros and cons

JimmyB

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I think you’re right. I seem to remember seeing some when I watched the Journeys programme about the Isle of Mann Steam Railway the other day
Yep, that's where I think I saw it :)
 

Rhinochugger

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The IOM steam at Port Erin has push throughs, or so I am lead to believe. I am sure somebody will correct me if I am wrong :)
I think there are quite a few 1:1 examples - the weight helps ;)

They were doing some work at Port Erin when were there - changing the station layout in some way :)
 

Ralphmp

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Bit of drift, but how did you travel there - air or sea?
 

ntpntpntp

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Last edited:

Paul M

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So overall, I think what folk are saying is that

live frogs aid certain locos to traverse points at slow speed, but

they require discipline in use to ensure “push throughs” don’t happen as this could/would cause a short circuit (depending on how the point blades and frog are wired).
Prime example of someone asking a question, and actually reading and taking note of the answers! No names mentioned.
 

Software Tools

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"Weighted" throw-over point levers are reasonably common on prototype railways in non-interlocked settings, such as yards etc.

These allow points to be "trailed" through easily and are very convenient when shunting..... as long as the wagons/trains concerned completely clear the points before moving in the other direction again.

E56A823E-930E-4974-AE31-42D78792DE86.jpeg
 

Ralphmp

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Sorry, one further question. When I connect the “feed” to the point frog and my isolating track, should I include a diode somewhere in the circuit? When I had a Massoth Reverse Loop module it came with diodes to connect into the feeds to the tracks and, although I installed them, I never really understood why they were needed. Is it to protect from surges or such like?

(I did do a Google on this but it didn’t help me much, I’m afraid.)


Thanks
 

dunnyrail

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Sorry, one further question. When I connect the “feed” to the point frog and my isolating track, should I include a diode somewhere in the circuit? When I had a Massoth Reverse Loop module it came with diodes to connect into the feeds to the tracks and, although I installed them, I never really understood why they were needed. Is it to protect from surges or such like?

(I did do a Google on this but it didn’t help me much, I’m afraid.)


Thanks
Ok different issue. I assume you are not talking DCC?

With the points live frog you need a switch to swop the feed to the frog.
Straight ahead it comes from the curved rail.
Curved it comes the straight rail.
With DCC a ‘Frog Juicer’ does the same thing.

Again assuming you are not talking DCC. The reverse loop module uses diodes to allow the positive feed to be whatever way you turn the controller. Thus when you stop the loco in the loop you needed to reverse the controller but the loco carried on in the same direction.
 

phils2um

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Just to make clear, What Jon just described applies to analog track power only. This is the diode setup in the LGB analog reverse loop track section sets No. 1000K and the newer 10151.

I think the diodes Phil is referring to are those provided with the Massoth 8157001 (and LGB 55085) DCC reverse loop modules. These are diodes that can be optionally added to the sensor leads. The diodes lessen the susceptibility of the track sensor segments to false triggering.

But to answer Phil's question, no, in general you do not want to put diodes on the power feed to a live frog whether you are using analog or DCC track power.
 

dunnyrail

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Just to make clear, What Jon just described applies to analog track power only. This is the diode setup in the LGB analog reverse loop track section sets No. 1000K and the newer 10151.

I think the diodes Phil is referring to are those provided with the Massoth 8157001 (and LGB 55085) DCC reverse loop modules. These are diodes that can be optionally added to the sensor leads. The diodes lessen the susceptibility of the track sensor segments to false triggering.

But to answer Phil's question, no, in general you do not want to put diodes on the power feed to a live frog whether you are using analog or DCC track power.
Ok different issue. I assume you are not talking DCC?

With the points live frog you need a switch to swop the feed to the frog.
Straight ahead it comes from the curved rail.
Curved it comes the straight rail.
With DCC a ‘Frog Juicer’ does the same thing. EDIT DCC ONLY

Again assuming you are not talking DCC. The reverse loop module uses diodes to allow the positive feed to be whatever way you turn the controller. Thus when you stop the loco in the loop you needed to reverse the controller but the loco carried on in the same direction.

Actually with Live Frogs as stated in my middle sentence above applies to both Analogue and DCC. Though the “Frog Juicer “ can only work with DCC.
 

Ralphmp

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Just to make clear, What Jon just described applies to analog track power only. This is the diode setup in the LGB analog reverse loop track section sets No. 1000K and the newer 10151.

I think the diodes Phil is referring to are those provided with the Massoth 8157001 (and LGB 55085) DCC reverse loop modules. These are diodes that can be optionally added to the sensor leads. The diodes lessen the susceptibility of the track sensor segments to false triggering.

But to answer Phil's question, no, in general you do not want to put diodes on the power feed to a live frog whether you are using analog or DCC track power.
Yes, they’re the ones. As I’m DCC (when not battery) I‘ll leave diodes out of the picture!
 

phils2um

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Actually with Live Frogs as stated in my middle sentence above applies to both Analogue and DCC.
Absolutely, I agree Jon. I should have made clearer that I was referring to what you had written here:
The reverse loop module uses diodes to allow the positive feed to be whatever way you turn the controller. Thus when you stop the loco in the loop you needed to reverse the controller but the loco carried on in the same direction.
 

Dan

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Use a poly switch to feed the frog. This is like having an automatic self resetting fuse. Also note that the Zimo DCC decoder with built in supercaps has capacitor storage and works in DC and DCC powered track. My Stainz has 7 of the 10 farad capacitors in series and after charging the caps will run in open air for over 10 seconds with lights/smoke/motor on!!