[Techgunner]

I have searched the interwebs extensively to help with this question. I have a second generation Aristo C-16 with the newer fan driven smoke generator running on DC power. The issue I am having is even when the reservoir is half full, the generator will shut off the power to fan and heating element. If I stop the loco and start it again, the fan and heater will run for about 40 seconds and then shutoff again. This is very frustrating. I understand it is there to safeguard the heating element from burning out, but that is what the on/off switch is for.

Has anyone ever bypassed the shutoff circuit on an Aristo generator, and if so, what did you do? If not, what smoke generator do you recommend in place of the Aristo? I heard Train Li makes a replacement, but haven't heard any reviews.

 

[Dan Pierce]

The Trainli unit is a fan driven heater unit with no electronics inside and about the size of the Aristo unit used in the newer diesels. These smoke units are tied to a decoder which supplies the motor/heater power. Motors are 4-5 volts, heater is 15 volts on older units and higher on the newer units.

 

[Techgunner]

Motors are 4-5 volts, heater is 15 volts on older units and higher on the newer units.

So in order to wire the TrainLi unit up to my DC power I would need to have two wire feeds going to the unit and step down the power to both with resistors?

 

[Pete Thornton]

So in order to wire the TrainLi unit up to my DC power I would need to have two wire feeds going to the unit and step down the power to both with resistors?

You'd be better off using a voltage regulator that outputs 5V or 15V. They are readily available for a few bucks. I have one on my LiIon battery pack that outputs 11.9V, as the loco has a 12V ESC which hates 14+VDC.

 

[Techgunner]

You'd be better off using a voltage regulator that outputs 5V or 15V. They are readily available for a few bucks. I have one on my LiIon battery pack that outputs 11.9V, as the loco has a 12V ESC which hates 14+VDC.

I thought voltage regulators required a constant input power to operate. I have several 5 volt IC 7805's, but I didn't think they would work on an input voltage that varies. If it will work, then that would be great.

 

[Greg Elmassian]

OK, so the auto-shutoff circuit in the Aristo unit is a joke, it does not work, and over the lifetime of the smoke unit it's behavior will change.

Like Pete intimated, you will need a regulated supply AND to wire directly to the heater AND you will have to determine the voltage that works, so an adjustable regulator would help.

Depending on how careful you are about running out of fluid, and how much smoke you want, you will probably come up with something in the neighborhood of 7 to 9 volts.

The fan is about 5 volts, and if you run constant voltage to the unit, you really should run it pretty constantly, or you will have a lump of melted plastic.

By the time you come up with the variable regulator, and enough heat sink (because you will draw about 1 amp), you would be better off with a regulated buck-boost converter (no heat sinks required) and program in your desired voltage:

5A DC Boost Buck Step-Up/Down Constant Voltage Current Power Supply Module Kit | eBay

Find many great new & used options and get the best deals for 5A DC Boost Buck Step-Up/Down Constant Voltage Current Power Supply Module Kit at the best online prices at eBay! Free shipping for many products!

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There are TONS of these available on eBay and Amazon.

p.s. a 1 amp 7805 takes a BIG heat sink to dissipate the power of 1 amp and an input of 12 volts.... these are series regulators and "dump" the excess voltage as HEAT. These buck boost converters are switchers and do not generate heat (hardly at all).

 

[Techgunner]

OK, so the auto-shutoff circuit in the Aristo unit is a joke, it does not work, and over the lifetime of the smoke unit it's behavior will change.

Like Pete intimated, you will need a regulated supply AND to wire directly to the heater AND you will have to determine the voltage that works, so an adjustable regulator would help.

Depending on how careful you are about running out of fluid, and how much smoke you want, you will probably come up with something in the neighborhood of 7 to 9 volts.

The fan is about 5 volts, and if you run constant voltage to the unit, you really should run it pretty constantly, or you will have a lump of melted plastic.

By the time you come up with the variable regulator, and enough heat sink (because you will draw about 1 amp), you would be better off with a regulated buck-boost converter (no heat sinks required) and program in your desired voltage:

5A DC Boost Buck Step-Up/Down Constant Voltage Current Power Supply Module Kit | eBay

Find many great new & used options and get the best deals for 5A DC Boost Buck Step-Up/Down Constant Voltage Current Power Supply Module Kit at the best online prices at eBay! Free shipping for many products!

www.ebay.com

There are TONS of these available on eBay and Amazon.

p.s. a 1 amp 7805 takes a BIG heat sink to dissipate the power of 1 amp and an input of 12 volts.... these are series regulators and "dump" the excess voltage as HEAT. These buck boost converters are switchers and do not generate heat (hardly at all).

Thanks Greg. Much appreciated.

 

[Greg Elmassian]

The auto-shutoff circuit depends on a microprocessor, but it has been shown that it's "algorithm", while clever, fails and causes the unit to either quit early (your issue) or never quit (molten plastic).

The other issue is that smoke fluid does not stay isolated from the electronics, and it soaks into the ends of the electrolytic capacitors and they expand and literally rip themselves from the circuit board.

I use these smoke units, but bypass the wiring and just run 4 wires out, 2 to the fan and 2 to the heating element, and then run this from a DCC decoder.

Greg

 

[Dan Pierce]

I also use the decoder to control the fan and heater and my decoders have 3 fan control settings and 3 heater settings. Smoke is different for idle, running, accelerating or heavy load, plus the fan is switched on/off for chuff on steam engines.