Bachmann smoke generators, a question of voltage ?

[The Shed]

Max, correct, adjust by turning the brass screw on the blue box ( potentiometer), voltage range adjustable less 2.5V to operate the module, i.e input 4V output 1.5V......................

Input voltage range: 4-35V
Output Voltage range: 1.5-35V (adjustable)
Output current: rated current 2A, maximum 3A (heat sink required)
Conversion efficiency: Up to 92% (the higher the voltage, the higher the efficiency)

Non-isolated step-down module, short circuit protection: current limiting, a fuse or PTC* is advisable ( as this is being used for battery operation), a fuse will (should) be already present.

*PolySwitch Resettable PTC Fuses, PTC (positive temperature coefficient) device.

 

[maxi-model]

Max, correct, adjust by turning the brass screw on the blue box ( potentiometer), voltage range adjustable less 2.5V to operate the module, i.e input 4V output 1.5V......................
Input voltage range: 4-35V
Output Voltage range: 1.5-35V (adjustable)
Output current: rated current 2A, maximum 3A (heat sink required)
Conversion efficiency: Up to 92% (the higher the voltage, the higher the efficiency)

Which is why I seem to see those big black finned things attached to voltage regulators more often than not ? Like the one in the picture I posted ? Given that smoke generators could have a significant current draw, under certain circumstances, would it be advisable as a matter of course in this application. If so what would I need to buy and where would it fit in relation to the DC-DC card (sorry !) Max

 

[Neil Robinson]

You don't need to purchase ten, just sometimes better value if you're likely to need several. The price seems to have increased a fair bit since a couple of years ago.
No golden rule for the voltage, as mentioned Bachmann smoke units are of variable quality. Set it to give an acceptable amount of smoke with the unit about 20% full of fluid.

 

[Neil Robinson]

Which is why I seem to see those big black finned things attached to voltage regulators more often than not ? Like the one in the picture I posted ? Given that smoke generators could have a significant current draw, under certain circumstances, would it be advisable as a matter of course in this application. If so what would I need to buy and where would it fit in relation to the DC-DC card (sorry !) Max

I doubt you'd need anything like the 2A rating without heat sink. If you feel you'd really like a heat sink purchase regulator(s) with them ready fitted.

 

[The Shed]

Max, depends on the info for the Smoke Unit, as to whether a heatsink will be required.

Can't help with the voltage, you could as a base point compare it with your existing installations, start at a low voltage and increment in small voltage steps, until you achieve your desired plume!

A dedicated Aluminium Heat Sink for the LM2596 IC is available, although any IC heatsink that measures 11x5x11mm will do the same job, it is affixed to the top of the LM2596 IC.

Aluminium Heatsink TO-263 TO-220 LM2596 2596 2577 Pi Thermal adhesive Cooler New | eBay

(The heatsink is supplied with pre-applied thermal adhesive pad for easy application – just peel back the backing and stick the heatsink straight on! 5) VERY IMPORTANT >> Do not make ANY permanent connections.

www.ebay.co.uk

 

[maxi-model]

Max, depends on the info for the Smoke Unit, as to whether a heatsink will be required.

Can't help with the voltage, you could as a base point compare it with your existing installations, start at a low voltage and increment in small voltage steps, until you achieve your desired plume!

A dedicated Aluminium Heat Sink for the LM2596 IC is available, although any IC heatsink that measures 11x5x11mm will do the same job, it is affixed to the top of the LM2596 IC.

Aluminium Heatsink TO-263 TO-220 LM2596 2596 2577 Pi Thermal adhesive Cooler New | eBay

(The heatsink is supplied with pre-applied thermal adhesive pad for easy application – just peel back the backing and stick the heatsink straight on! 5) VERY IMPORTANT >> Do not make ANY permanent connections.

www.ebay.co.uk

Thank you Mr Shed (and all others). Both items now ordered. I'll take your tip on setting up the voltage. No problem with doing it static, although I have a number of Massoth rollers (need them when you have anything up to a 2-6-2 + 2-6-2 to test run) as I can switch the motors off on most. Max

 

[The Shed]

Max, just a thought, (and yet another small expense!) this item may well be useful to have in your armoury for testing and achieving the desired voltage level, same type of module as previously mentioned, has as an useful aid as in small screen and the ability to monitor the input and output voltages.

For testing for an acceptable voltage level to power the smoke unit, the screen will display the output voltage as you adjust the screw....saves the bother of keep attaching a Multimeter!

Once achieved, hook a Multimeter upto the original item as ordered, turn screw until desired voltage level, job done!

DC-DC Buck Step Down, converter Module LM2596 DC/DC 4.0~40V to 1.25~37V , LED | eBay

LM2596 DC-DC Step down Buck converter DC 4~40v to 1.25~37v with LED display. Current limit protection and thermal shutdown function. The LED display can be turned off by button (Nixie switch).

www.ebay.co.uk

 

[Greg Elmassian]

In terms of power, actually current is more important, as the resistance will change as the fluid level changes.

The ideal case would be a current limited supply, so when it runs out of fluid, there is less chance of harm (it will draw more current when dry)

Greg

 

[maxi-model]

Max, just a thought, (and yet another small expense!) this item may well be useful to have in your armoury for testing and achieving the desired voltage level, same type of module as previously mentioned, has as an useful aid as in small screen and the ability to monitor the input and output voltages.

For testing for an acceptable voltage level to power the smoke unit, the screen will display the output voltage as you adjust the screw....saves the bother of keep attaching a Multimeter!

Once achieved, hook a Multimeter upto the original item as ordered, turn screw until desired voltage level, job done!

DC-DC Buck Step Down, converter Module LM2596 DC/DC 4.0~40V to 1.25~37V , LED | eBay

LM2596 DC-DC Step down Buck converter DC 4~40v to 1.25~37v with LED display. Current limit protection and thermal shutdown function. The LED display can be turned off by button (Nixie switch).

www.ebay.co.uk

Thank you, but too late I have already made my purchase. However, I do have a multimeter, so carrying out the adjustment as per the video should not present a problem. But I will keep this search on file. It is interesting when one starts looking at similar items what else is out there, LED displays, higher amp ratings and built in heat sinks, etc'. Max

 

[maxi-model]

In terms of power, actually current is more important, as the resistance will change as the fluid level changes.

The ideal case would be a current limited supply, so when it runs out of fluid, there is less chance of harm (it will draw more current when dry)

Greg

I am getting mixed up with the terms "current" and "amps". the latter term which I have always assumed refers to the actual current drawn. I understand the term power as being defined in watts - The ESC's I am using are rated at 100 watts, as is my mini drill. So I found this What are amps, watts, volts and ohms? to try to help me understand. It would seem there is a subtle, to me, difference between the terms current and amps that I never previously understood. What measures, or device would you suggest Greg to offer a form of current protection to a smoke generator, and is there a link to show me what I should be looking for ? Would it be used in conjunction with a voltage regulator and if so are there devices that combine the two functions ?

Are we saying even with a restricted voltage there is still a risk of the smoke generator overheating and causing damage to surrounding plastic structures ? You mentioned wicks in a previous post - the Bachmann units do not use a "wick" as I understand it, a woven fabric item (much as you find in meths burning live steamers). Is the structure in the attached picture termed as a wick ? Not doubting you, just need a clarification - as in "two nations divided by a common language Max

 

[JimmyB]

I am getting mixed up with the terms "current" and "amps". the latter term which I have always assumed refers to the actual current drawn.

Max I have always been under the impression that current drawn is measured in Amp, like talking about speed and MPH, speed is measured in MPH (other units are available )

 

[PhilP]

Max I have always been under the impression that current drawn is measured in Amp, like talking about speed and MPH, speed is measured in MPH (other units are available )

Good analogy..

 

[maxi-model]

Max I have always been under the impression that current drawn is measured in Amp, like talking about speed and MPH, speed is measured in MPH (other units are available )

Agreed. I only mention it as I just seem to be picking up that the term "current" is not just amps on it's own. Perhaps I am just overeading things. I suppose if I really want a definition of current I should really stick my fingers in a light socket ( commiting the requisite rubber soled shoes) Max

 

[Gizzy]

The current is measured in Amps.

Resistance is measured in Ohms.

Potential Difference is measured in Volts

Power is measured in Watts.

The current rating of a UK plug is 13A as determined by the fuse, but you should put in a 3A fuse for say a bed-side lamp.

The mains voltage is 230 Volts AC.

Using water as an analogy, think of Volts as flow and Amps as pressure....

 

[Greg Elmassian]

Wrong Gizzy! actually bass-ackwards.

using the water analogy:

volts is pressure (notice you can measure pressure or volts anywhere without disturbing the flow)

amps is flow, the quanity of electrons or water actually moving... in electronics the amp meter must be in SERIES with the circuit, like a shunt, or the water analogy, something that measures cubic feet per minute (or liters, etc.)

also to continue the analogy, you can always measure volts or pressure even if the circuit is not "live"... you can measure the water pressure in your house even if nothing is flowing... and you can measure voltage on a battery even if the circuit is "off"

but current/amps is only measurable when the circuit is complete, i.e. electrons moving... same with water flow/consumption... you have to have a tap open to measure the gallons/minute.

Greg

 

[Greg Elmassian]

To the previous question, the only way I have seen a high-output smoke unit be able to protect itself, is with an "intelligent" circuit, Aristo used a microprocessor sampling current.

Again, perhaps this nuance was not noticed... the smoke unit will draw LESS current when it runs out of fluid... and this is when the damage occurs.

Happy to explain the physics of this, has to do with the conservation of energy, basic tenent of physics... to make it simple, when the unit is not doing work converting fluid to vapor, then it is doing less work, and thus draws less power... given a constant voltage, clearly it must draw less amps.

Greg

 

[Dan]

LGB uses the '5 volt' smoke unit and gives it between 6 to 6.8 volts for better smoke. I believe the Seuthe rating is 4 to 7 volts for this smoke unit, so 6 volts would give good smoke output. On another note, I have seen Bachmann use 12 volt leds for the lights in their engines, not sure how the Annie is configured, but the print does not show any egulators or resistors. I converted mine to DCC many ytears ago and installed a 12 volt regulator.

 

[Greg Elmassian]

If you examine the Bachmann "12v LEDS" you will find a very small resistor in the leads from the LED somewhere, once I found an 1/8 watt resistor, which was almost invisible.

Greg