electric drive on the cheap?

[chooch]

Put a smooth steel disc or something and use a bicycle hand brake.
Plum Cove control panel has some kind of rheostat--turn knob, that you can use to limit speed even if you turn the throttle all the way On. Good for limiting speed with kids, adults, learners or those just Trying a loco unit out.

For comparisons to other controllers, what is the PRICE of the 4qd, is it USA made ?
Have you looked at the other sites I mentioned for information or ideas?
chooch

[fresnojay]

Mike,
I have something that I can help you out with and have it on hand. It will take care of your entire controller needs. Hand unit and controller. PM me if you are interested. I will be at the NG meet next weekend and can bring it too so free delivery .

Jason

[Kimball McGinley]

Yes, most small (100 Watt, 200 Watt, etc.) electric scooters are just on-off, even if it is a twist throtle. My 400 watt E-zip does have 3 speeds, I do not know how that is accomplished however. No regenerative braking either; they all coast freely and require wheel brakes to slow and stop.

[Harlock]

Yes, most small (100 Watt, 200 Watt, etc.) electric scooters are just on-off, even if it is a twist throtle. My 400 watt E-zip does have 3 speeds, I do not know how that is accomplished however. No regenerative braking either; they all coast freely and require wheel brakes to slow and stop.

Thanks, I was kind of afraid of that. The braking can be made up for with a bicycle brake as someone else mentioned, but not having continuously variable acceleration could make it not very fun to control.

[one_inch_railroad]

Harlock,

I will second the recommendation for the Syren 50 motor controller. It's only $120 bucks compared to the $3-400 you would spend on a 4QD board.

The switching frequency used in 32Khz well above the range of human hearing so you don't get that annoying PWM humming noise.

Synchronous regenerative drive:
Going one step farther than just regenerative braking, a SyRen motor driver will return power to
the battery any time a deceleration or motor reversal is commanded. This can lead to dramatic
improvements in run time for systems that stop or reverse often, like a placement robot or a
vehicle driving on hilly terrain. This drive scheme also saves power by returning the inductive
energy stored in the motor windings to the battery each switching cycle, instead of burning it as
heat in the motor windings. This makes part-throttle operation very efficient.

Thermal and overcurrent protection:
SyRen 50 features dual temperature sensors and overcurrent sensing. It will protect itself from
failure due to overheating, overloading and short circuits.


Compact Size:
SyRen utilizes surface mount construction to provide the most power from a compact package.
Its small size and light weight mean you have more space for cargo, batteries, or can make your
robot smaller and more nimble than the competition.

Carefree reversing:
Unlike some other motor drivers, there is no need for the SyRen to stop before being
commanded to reverse. You can go from full forward immediately to full reverse or vice versa.
Braking and acceleration are proportional to the amount of reversal commanded, so gentle or
rapid reversing is possible.

If I were you this is how I would wire it up.

Option 3: Analog One-direction with
forward/reverse select on S2

A signal on S1 of 0v corresponds to the motor being fully
stopped. 5v corresponds to full power. A second signal is
fed to S2. If the signal on S2 is greater than 2.5 volts, the
SyRen will drive the motor forward. If the signal on S2 is
less than 2.5 volts, the SyRen will drive the motor
backwards. The signal on S2 can be either an analog signal
or a digital signal. This is useful for vehicles with a reverse selector switch.

All the inputs and outputs are screw terminals.

Just wire up a 5K linear pot using the onboard 0V and 5V outputs with the center wire fed into S1. This pot would control the speed of your motor. Then have a switch wired from 5V to S2. When the switch is closed and S2 gets the 5V the locomotive will go forward. When the switch is open it will go backwards.

I would also recommend getting a 5V USB to TTL serial cable so you can hook up the controller to your computer to program the ramp settings. The software is free and uses a graphical user interface. No need to write code or anything like that.

Here is a link to a USB to TTL serial cable from Sparkfun electronics.

https://www.sparkfun.com/products/9718

[chooch]

To: one- inch-railroad.
What an Excellent post, Excellent!! So thorough and descriptive you just can`t beat the little controller for what it does and the low cost. The Syren 25 is less cost and also works Quite well. I use a couple and know of others that use either one.

I don`t know the Technicals like you described, just know I like the controller and it is Simple to hook up. I did mount it on a Heat sink though where I had to mount it.
thank you.
chooch

[cbrew]

the only thing i would add to one- inch-railroad post is adding a 100k resistor across 0v and s1, this way if anything was to happen to the cable between the controller and the handheld, the loco will go to full stop. with out it, the input will float and cause a run away.

Mike the Diagram i sent you supports this mode (I forgot to state that)

Option 3: Analog One-direction with
forward/reverse select on S2

[one_inch_railroad]

I forgot to ask if you were going to use one motor or two. If you use two I would suggest using the Sabertooth 2x32 so each motor has its own output channel.

Another advantage of the 2x32 is that there is an onboard USB mini B connector so you wouldn't need to use the USB to TTL serial converter

The Sabertooth 2x32 is only 5 dollars more than the Syren50

I would hesitate recommending the Syren 25 for a 1.5" scale ride on application. Perhaps it would be enough but I would rather spend a few extra dollars and have a board rated at a higher capacity than what is needed so if pulling a longer heavy load on a hot day you don't have to worry about burning out the motor controller. I have heard of people with 4QD boards doing this quite often.

I know you will not be using radio control but I thought I would mention that there was a thread on radio control quite a long time ago. Chiloquinruss from Train Mountain said:

This is the operating rule at Train Mountain and so far the only commercial rig that has passed the fail safe test are the units currently sold by Mountain Car. All others have not passed the test. Russ

The interurban I wired up for radio control passes the failsafe test. When the car is running I have turned off the radio several times simulating a loss of signal. It only takes 1 second for the car to stop once the transmitter has been turned off. If I turn the transmitter back on it takes a few seconds for the transmitter and
receiver to re-establish their link, but once they do the car starts moving again. I was quite impressed.

Adding to what Cbrew said on using a 100K pulldown resistor. I would also think about wiring a deadmans switch in series with the potentiometer. I like these arcade style buttons from sparkfun. They are nice and big so are easy to find with your thumb/fingers instead of those little momentary pushbuttons. They have a very nice "click" to them and because that actual switch is a microswitch it doesn't take a lot of effort to hold it down. If you have too much spring tension your hand would fatigue over time and thats definitely something to consider too

https://www.sparkfun.com/products/9336

You could also wire a key switch in series with the potentiometer so that you can leave it sitting somewhere at a meet and not have to worry about some young kids or any other uninvited engineers taking it out for a spin!

https://www.sparkfun.com/products/11473

[cbrew]

tho i have run the original box cab with a syren 25, it did have issue moving my 8 cars plus cold steam engine at train mountain at slow speed, because of that, I have moved up to the syren 50 for all the box cabs.

as for needing to move to the sabertooth for twin motors, i am not sure if you need to,
after speaking with the techs, i wired two syren 50 to four 500w motors (with the thought we may need to add two more syren's later) to our surprise, the syren 50s commanded anything you hooked to the loco like a boss.

i designed the system to be two distinct and redundant systems. we will be putting it through its paces again this weekend along with my twins (just applying the finishing touches tonight)

[one_inch_railroad]

cbrew:

Thats an excellent point. You could also just wire up two Syren50's to the same Pot. I know Harlock said he wanted to keep costs down. Buying 2 Syren50's would set you back $240 dollars, still less than a 4QD board though! Whereas the Sabertooth 2x32 is only $125. Plus with the Syren50's you would also have to order the USB to TTL serial cable. I know Harlock said he wants a nice ramp so the engine starts and stops gradually.

But if he doesn't mind spending a bit more money two Syren50's would still be a great option.

Another thing I like about these boards is that you can control as many motor controllers from a single Pot. as you want. I asked there tech support people and they said they have customers that have wired up as many as 10 of them.

One of the downsides to the one inch scale Iron Pony engines is that you can only MU two units together. With the Decho units you can wire up as many as you want. A friend of mine told me he was St Croix and they ran 10 Decho engines together. He said you could really feel the dynamic brakes with 10 engines. Now do you really need to be able to MU more than two engines on a regular basis. No, probably not. But it's a nice thing to have if your at a meet and want to MU with another guys engines and have a four unit lashup or something like that etc.

If I were selling engines commercially I would think MU'ing more than two locos would be on my priority list. I know the question of MU'ing electric engines comes up here from time to time.

[cbrew]

well my point was there is two 500w motors on each syren 50.

as for MUing the syrens, i will be able to MU as many units to on controller as i wish (with in reason of course)
and it only takes three wires to do so. if my math is right. I should be able to MU the large loco to my box cabs with out issue. tho i may need to revisit my spreadsheet on the gear ratios.

[chooch]

cbrew and one-inch-railroad--
Are you both saying Simply, the Syren controllers are an OK product depending on what you might build for a locomotive-large or small, how many cars (and load)you want to pull and on what type railroad. (grades, etc.)And they will handle pretty high watt motors--500?
thank you.
chooch