Here is what I meant about 'using' a Kato's existing board.I only needed to use a balancing resistor to make the the lamps on the cab & the ditchlights match in intensity, fairly easy.Hope you find it interesting.
http://cs.trains.com/mrr/f/88/p/198637/2175074.aspx#2175074
I agree with T.Z.
In my DC jobs I do not have a double rectifier (as I know of), in this scenario, (the circuit above) it seems the goals were to really cut down the voltage to the LED's, if each Diode eats 0.7 Volts, it would take that circuit 4.2 volts to begin to operate (my estimate), so yes, that is a dead initial start! Especially when you consider it is in series with the motor, add in that start voltage & you may very well be up high in the 'Normal' cruising range in a straight motored model!!! I have not done an Ath BB lighting project in a while, but I have a few I'd like to!Do not expect anything soon, but I will post here & give specifics, when I get to it.The requirements I have will be;1 Headlight2 FWD Ditchlights1 Rear Light2 Optional Rear Ditchights (Branchline Road Switcher, -no turn table access).1 Optional blinking BeaconAll in DC & directional, & directly wired, (no circuitboard cheats [like in a Kato])..
Thanks,
Well, I have used 1/2 that circuit, but with a light bulb not an LED. That is I have one bridge rectifier with a 1.5V lamp across it. It works great.
In the circuit shown I don't understand why there is the second diode in line with the LED. I assume it is limiting the reverse voltage to the LED. Even so why add the 2nd bridge rectifier forcing more voltage through the LED section of the circuit. I would replace the 2nd bridge rectifier with two diodes, in parallel of opposite polarities.
Are you using circuit components rated for high enough voltage and current?
And of course a locomotive equipped with such a circuit is going to have a higher starting voltage. That is the whole point. That pre-starting voltage is what lights the lamp.
Hey Jim,
No light boards..these are your standard Athearn Blue Box models. The motors happen to be really clean and they're strong runners. The heat coming off the bridge rectifiers was way to hot after hooking up the circuit to the motor with aligator clips. I just can't figure out why anyone would use that circuit.
I'll just go with the simple LEDs & resistors. They draw some current...using 1.8mm LEDs..I believe they need about 3 Volts but its a trade off...so you loose some power but its negligible I think?. And I'm planning on putting 2 lights up front and 2 in the rear. Have to see if that depleats the power to much.
Thanks
Paul
PennStation It really sucks the power up as well.
It really sucks the power up as well.
I am also using DC and I would not use this circuit. Being in series with the motor is going to cause a substantial starting voltage increase. It sounds like you already found that out.
When I do a re motor, flash removal, N/S wheels, more weight, etc, one of the goals is lower starting voltage @ a given speed, not a higher one.
PennStation the other option will be to just make a simple LED circuit using a few LEDs and fiber optic filament. That is just LEDs + resistors. Very simple and no heat generated.
That is what I do. If it already has low quality LEDs on a decent board like a Kato, I desolder and install better LEDs.
Jim
Has anyone installed this circuit into a DC engine? I am hesitant to use it because I built the circuit and while testing it the bridge rectifiers get very hot and either it is supposed to get very hot (which seems wrong) or I've got something wired wrong....but I don't think so. It really sucks the power up as well. Anyway, just wondering if anyone had any experience with it? I intend to light some old Athearn BB U30C's (PRR)..headlights, number boards, back up lights..the other option will be to just make a simple LED circuit using a few LEDs and fiber optic filament. That is just LEDs + resistors. Very simple and no heat generated.
Just curious if anyone ever used this circuit. And wondering why? I found it through one of the forums .. Not sure if it was MRR. Originally I was trying to see if there is anyway to light in DC and get so called lights on while the engine is standing still. Don't want to use batteries. And it's just not worth it to install DCC in these engines.