Help me find one of these AC transformers..

[peteski]

To protect against overloading the transformer (and blowing its internal fuse) , you could add a polyswitch, or other type of fuse, between the transformer output and the throttle input.

True. 

[Greg Elmassian]

Looking at the circuit, it seems that you could use a DC supply too. The incoming AC is immediately rectified and filtered to DC.

Greg

[peteski]

Looking at the circuit, it seems that you could use a DC supply too. The incoming AC is immediately rectified and filtered to DC.

Greg

Look again Greg:  They tap the AC signal from the bottom leg of the rectifier to produce pulses for the throttle circuit. It needs AC.

[Greg Elmassian]

That's why I said seems, was not looking in depth, saw the voltage divider, but you are correct, that's apparently the pulse source, 120 hz?

Greg

[peteski]

That's why I said seems, was not looking in depth, saw the voltage divider, but you are correct, that's apparently the pulse source, 120 hz?

Greg

No, it is on the AC side of the rectifier, so 60Hz, half-wave pulses.

[Greg Elmassian]

This is what happens to a person who goes by memory instead of actually going back and looking at the schematic.

Score 2 for Petski...   

If you nail me on the TCS thread, that will be the third strike for today.

Oh, but I am done for the day, see you tomorrow 

[peteski]

This is what happens to a person who goes by memory instead of actually going back and looking at the schematic.

Score 2 for Petski...   

If you nail me on the TCS thread, that will be the third strike for today.

Oh, but I am done for the day, see you tomorrow 

Not out to get you - just trying to prevent him from getting a power source which would not work. 

[peteski]

I think that there is something worth mentioning about this throttle:  It will most likely make your DC model (the motor in it) buzz at low speeds.  While the throttle utilizes the "new fangled" PWM motor control, the pulses are at the same rate as the AC power in your house: 60Hz or 60 times a second.  That is an audible frequency. Some early (and some current inexpensive) DCC decoders use low frequency PWM to drive the motor and they also buzz.  But most DC decoders uses much higher PWM pulse frequency (like 20kHZ or 20,000 times a second). Those are beyond the range of hearing.

[coosvalley]

Thanks for mentioning that, if it bothers me too much I'll stick with my rusty reliable MRC Controlmaster X. But I really want hand held control, and the other option that I like for this, the MRC controlmaster 20, goes for a pretty penny on ebay these days..So this is an experiment, and folks who have these seem to like them.

I think I will just use a small power pack for the AC, as that gives me some sort of short protection. Mostly I was just hoping to cut out the middle man(power pack), so to speak. It would be a cleaner slimmer install with just the wall wart, but I think I can fit a small Atlas or Bman power pack, mounted between the frame of the layout, for a low profile, no snag solution.(I'm trying to keep everything recessed within the frame for easy moving)Despite being able to find that specific wall wart at 3 vendors, either shipping costs or minimum orders have made that the more expensive route, for what amounts to basically the same result.

[peteski]

If you have a old throttle unit which has the AC accessories output you could use it to power up your 1.5 AMP PWM WALK-AROUND THROTTLE,  or at least to try it out while you are looking for a suitable wall-wart.
The AC accessories output is usually 16V (which is perfect for that PWM throttle). The only difference is that you will not get a full 1.5A out of the PWM throttle (but you likely don't need it anyway). But it will function just fine.  Or just make this your permanent setup (using the old throttle AC output instead of the wall-wart).

[coosvalley]

If you have a old throttle unit which has the AC accessories output you could use it to power up your 1.5 AMP PWM WALK-AROUND THROTTLE,  or at least to try it out while you are looking for a suitable wall-wart.
The AC accessories output is usually 16V (which is perfect for that PWM throttle). The only difference is that you will not get a full 1.5A out of the PWM throttle (but you likely don't need it anyway). But it will function just fine.  Or just make this your permanent setup (using the old throttle AC output instead of the wall-wart).

I think I will just use a small power pack for the AC, as that gives me some sort of short protection.

Good idea!. ..But, yes, it looks like this is the solution if I cannot get one of the recommended AC adapters(for a reasonable price!)...

[peteski]

Good idea!. ..But, yes, it looks like this is the solution if I cannot get one of the recommended AC adapters(for a reasonable price!)...

Or just take your new throttle for a test-run while you are researching the AC adapters. This doesn't have to be a permanent solution, and you are probably curious about how this new throttle works. 

[metalworkertom]

I just ordered 2 of these throttles in kit form. What is your opinion of them ?