Tortoise connectors and transformer problems

[Killybegs]

Discovered the benefit of the connectors today when we ran into a transformer problem - it kept cutting out. Being able to unplug the motors one at a time made it a lot easier to study the impact on the transformer. We got down to just six motors (90ma) before before the transformer stopped cutting out. As another 'identical' 1amp transformer happily operates 55 motors (825ma), I guess there is something wrong with the transformer. Actually that should be transformers as two units bought at the same time behaved identically. I assume the cut out must be set too low. We tried swapping transformers between circuits (the turnouts are on 3 circuits of 35, 20 and 12 units) but the problem always followed the transformer.

 

Waiting to hear what the supplier has to say!

[Kenton]

Are these separate open transformers or WallWart plug in enclosed units. Some of the Wall Warts are very poor spec and not so good for this type of use. They are designed as cheap (v.low ma) mobile phone (etc) charger power units. The voltage output is also not very high and I have seen ones ranging from ~3v to 18v If you are driving several Tortoise at the same time, or have them incompletely set up as still idling and not at their full stop points, then I'm not surprised that the transformer fails/overheats/can't keep up the power required.

[Killybegs]

Are these separate open transformers or WallWart plug in enclosed units. Some of the Wall Warts are very poor spec and not so good for this type of use. They are designed as cheap (v.low ma) mobile phone (etc) charger power units. The voltage output is also not very high and I have seen ones ranging from ~3v to 18v If you are driving several Tortoise at the same time, or have them incompletely set up as still idling and not at their full stop points, then I'm not surprised that the transformer fails/overheats/can't keep up the power required.

Thanks for your reply. These are expensive enclosed transformers from a reputable source. I assume that, provided the switch on a tortoise has completed its travel, it is no longer idling. According to the instructions that come with the motors, they use more power at stall than they do when operating, so where does idling fit in that equation?

[Donw]

You don't specify the transformers. All devices sold in this country should have a rating plate/label in them this should state the input and hopefully also the output. If it only puts out about 100ma (probably enough for a mobile phone charger) then six tortoises would be the max load. If the rating is ok but the transformer delivers the manufacturer should answer for it.

 

One trick if you use an AC supply and feed half cycles through diodes (i.e +ve or -ve half cycles) you can increase the load assuming they will not all be set the same way at once. Use the half cycle supply worked fine for me with no problems over two day exhibitions. Using a bi-polar led in each motor lead showed which way it was set.

 

Donw

 

 

[naugytrax]

where does idling fit in

 

You are right in believing that Tortoise switch machines never idle. Either they are moving, and consuming about 5 milliamps, or they are stalled because they physically can't move any further, and consuming about 15 mA. People sometimes confuse Tortoises with the Fulgurex and Lemaco slow action switch machines, which turn themselves off when they reach their limits of travel.

[Killybegs]

You don't specify the transformers. All devices sold in this country should have a rating plate/label in them this should state the input and hopefully also the output. If it only puts out about 100ma (probably enough for a mobile phone charger) then six tortoises would be the max load. If the rating is ok but the transformer delivers the manufacturer should answer for it.

 

One trick if you use an AC supply and feed half cycles through diodes (i.e +ve or -ve half cycles) you can increase the load assuming they will not all be set the same way at once. Use the half cycle supply worked fine for me with no problems over two day exhibitions. Using a bi-polar led in each motor lead showed which way it was set.

 

Donw

 

Thanks, I will bear that in mind. The transformers are rated 1amp and the supplier has already agreed to a full refund.

[jamie92208]

That's very useful to read as I had some problems with voltage drop using 1 amp transormers. As I brought more Tortoises into use the output dropped from about 16.5V to 13.5v which caused some cheap 24 v relays to stop operating. The moral of this is that I should ahve bought 12volt ones in the first place and not been a cheapskate. Now I always make sure that there is enough oomph in the 12v circuit for all the auxilliaries and keep that separate from the traction circuits. I hadn't appreciated the extra current at stall.

 

Jamie