Frog problem solved!

I think it does that by if there is a short, switch the frog polarity, otherwise leave as is, it switches fast enough that the momentum of the loco carries it through, and must also be quick enough for the decoder to avoid a reset as it would when a dead spot is present and the voltage for the decoder drops too low.

Jim

 

Hi Andy, these are sold for DCC use, is your dad's outside layout DC or DCC, in my experience these devices will not fix blade problems, are those points e.g. Electrofrog or Insulfrog, i.e. metal or plastic.

Considering metal frogs only, as not necessary with plastic frogs.

Scenario 1, DC, typically a siding is dead until powered from the track it branches off from via the blades, the blade sets the frog polarity and powers the siding from the frog, so no problem with frog polarity.

If the blade contact with the stock rail is poor then blade, frog and siding will not be powered reliably.

Scenario 2, DCC, both siding and the track it connects to are typically both live at all times as power is fed to both via droppers attached to a power bus, this would result in a permanent short circuit with an uninsulated metal frog.

Considering Peco Electrofrog points with DCC, when the siding and main track are both powered the frog has to be isolated, usually via an insulated joiner at the exits from the frog and insulated from the blades either by cutting links on later versions or by cutting rails on older versions.

Power is fed to the then insulated metal frog and polarity switched either by an external switch, e.g. on my railway either a microswitch activated by the moving tie, a slider switch that also provides the tie movement or in the case of point motors a switch attached to the point motor.

Alternatively use electronic devices like 'juicers' units from Gaugemaster to polarity switch.

They are not required for Insulfrog type points as the frog is non-conductive.

Even so if the blade contact with the stock rail is poor then the blade alone will not be powered properly, e.g. even the weight of a loco on it can cause intermittant power loss through blade movement sideways or vertically.

Some blades have wipers that can be tweaked, some rely on blade against stock rail, both types have their weaknesses.

I think that it is unlikely that these devices will help with faulty powering of blades because travelling into the frog via the faulty blade may not generate the required short to trigger it to switch polarity and feeding power back from the frog will be blocked by the cut link or rail cut that isolates the blade from the frog anyway.
A rather long answer I'm afraid

Jim

 

I have tended to avoid these units as they are IMO an expensive opt out for actually wiring the frogs as I mentioned above, especially if you have a large number of points, personally the only place I would use them is on a reversing loop with a point sprung one way, however this is not easily implemented in 4mm scale due to the light weight of rollingstock.

Manually wiring is not difficult, plenty of info available, it has been covered on this forum in recent times too, modifying old Peco Electrofrog points takes the time and effort.

Jim