Stupid question about DC walk-around throttle

[Paul M.]

I was reading a listing on eBay about a walkaround throttle. It said it could be used for N/ HO scale. I model HO scale. However:( wait for the stupid question )

It says:

The model 851's high impact styrene case measures only 4" X 2" X 1". The inside is packed with circutry. No additional circuit boards need to be installed. Simply wire it to an existing 12VAC to 18VAC power source and to your tracks and you're in business!

Does it output in DC or AC? I have a Bachmann Spectrum Magnum power pack that I'll use for my "power source"

Thanks for reading this,

Paul

[Atlantic Central]

Paul,

It most likely puts out DC, but info like a name brand would be helpfull

Sheldon

[Paul M.]

Sheldon:

Here's a link:
http://cgi.ebay.com/AWESOME-HO-SCALE-WALKAROUND-THROTTLE_W0QQitemZ260095983371QQcategoryZ19142QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[lanny]

Hi Paul,

It sure 'sounds' good ... however, I would contact the seller and tell him the specific power pak you are using and ask him if there are any known problems, power, etc. with this device and your power pak.

I use an MRC Control Master 20 with the MRC hand held throttles which run about $22.00 with cable, at online RR stores. This powerpak can run anything from 'Z' to 'G' depending on what position the 'guage' switch is in. It works beautifully.

Experts like Hunt, Jim B., Nigel and many others can give you electrical info ... but I wonder if you might need something more 'robust' than the power pak you have in order for this to work 'as advertised'?

lanny nicolet

[lanny]

PS to Paul,

Your question is definetely NOT a stupid question!

We all learn when questions like yours are asked on this forum.

lanny nicolet

[Atlantic Central]

Paul,

Yes, you hook it up to an AC source and you DC that is filtered and controlled to run your trains. Looks like a decent product.

Sheldon

[glennk28]

A club I used to operate at used several different throttles like this.  In fact, we had a standardized 4-pin plug system to feed them AC and send DC to the track. We had MRC, Troller, and handmade throttles--as I recall the MRC's had to have a rectifier installed to be able to use them this way--but it made for a good way to operate--If this one takes AC input you can even use an old Lionel transformer to power it.  gj

[Jim Banner]

Pulse Width Modulation is pretty standard stuff for dc motor control.  Most if not all DCC decoders use PWM to control motor speed.  PWM improves the low speed performance of most locomotives.  The rest do not need it.  Depending on the repetition rate of the pulses, it may make the motor growl or whine or the rate might be too high to hear.  You might want to ask the seller about this.

If your power source can put out 1.5 amps ac then it will power this throttle up to its maximum.  That would be a power pack rating of about 25 VA (I am not sure what your Spectrum Magnum is rated.)  It will not provide more power to the rails than the power pack can deliver.  What it can do is provide better control of that power.

[Tony Walsham]

Looks like a quality product.

Sheldon said:  "Yes, you hook it up to an AC source and you DC that is filtered and controlled to run your trains. Looks like a decent product."

As Jim says PWM is perfectly good for all DC locos.
However, a PWM output is not filtered DC and should not be used to power locos that are equipped with DCC decoders.  The pwm signal can "confuse" them, and in a worst case scenario, actually damage the decoder.

I would ask the maker if they are prepared to guarantee the product to be safe with DCC decoder equipped locos.

[msowsun]

I don't think this is really a "Walkaround" throttle. I would call it a "Tethered" throttle. You can only walk until you run out of wire length.

A true "Walkaround" allows you to unplug the throttle and plug in at a different location while the train continues moving.   

[Jim Banner]

I don't think this is really a "Walkaround" throttle. I would call it a "Tethered" throttle. You can only walk until you run out of wire length.

A true "Walkaround" allows you to unplug the throttle and plug in at a different location while the train continues moving.   

The product under discussion is definitely a "tethered throttle."  But also a "walkaround throttle" in my books.  They were originally named "walk around throttles" because they were not fixed in place like a regular power pack or a Marnostat.  You could walk around with them and still control your train.  Throttles that would keep the train running even when the throttle was unplugged were called "memory throttles."  And when unplugged, they could not control your train.

If we really want to change the definition of walkaround, let's apply it only to throttles that you can unplug and walk around with, still in complete control of your train.  In other words, wireless throttles.  I think we could all agree that these are "the true walkaround." 

[Paul M.]

Thanks, everybody. I just might get it.

[lanny]

Just one more quick note regarding Jim B's last post on this topic. The difference between a true 'walk around' throttle as opposed to 'tethered' throttles.

By Jim's definition, which I completely agree with, my Control Master 20 which is advertised as having a 'walk around throttle', really doesn't. I can set the speed/ momentum, etc.  that I wish the locomotive/train to run at from point 'A', then unplug the MRC throttle. The train will continue running at those settings.

But to change anything, I have to 'plug' the throttle back in at point 'B' or back at point 'A'. So it is still, for control purposes a 'tethered throttle'. The plug-ins are standard phone jacks, so it would be easy to have several different plug ins on my layout.

Thanks for making that clarification, Jim. I suspect that a true 'walk around throttle' is probably not something that is available for the MRC DC/Analog power pak I use.

Or is it? :-)

lanny nicolet