I was discussing this with someone and said when I found the circuit I'd post it. Well her 'tis; http://www.members.optusnet.com.au/nswmn/con_brill_dc.htm
Auto reversing constant headlights...
- Thread starter tramcar trev
- Start date
Tramcar Trev said:
Trev I think it was me that you were discussing this with.
The output of the motor controller I am using has a constant voltage across the motor output but the motor does not move.
The LEDs across the motor output both light so all I can think of is that there is not enough current to move the motor but enough to light the LEDs.
12V across a motor at throttle neutral and it does not move, move throttle either FWD or REV and motor moves LEDs both stay lit.
It is the weirdest thing I have seen in my time as an electronics tech, all I can guess is that the output is from a controlled current source i.e. voltage is present but current is limited depending on throttle position.
The OEM told me that I could not get directional lighting by putting LEDs across the motor output but sold me a radio controlled relay to do the switching (maybe they saw me coming).
Yes now I think of it it was you.... Naturally you have checked that the motor runs? I threw out 6 dead Li-ions cuz my meter would not detect a voltage but it was a faulty meter, mad scramble through the recycling....
The motors definitely run, the train runs smooth as silk.
Contacted the OEM about the LEDs being on all the time and this is the reply.
"Syren is designed to drive an inductive load, like a motor, and not a resistive one, like an LED. So the LED will always be on."
I will continue to play with the lighting I have found a circuit that use the RC relay with a different config to what I am using so I am going to use that one.
Maybe I'll make it company policy that the front light is always lit.
You can get away with anything by putting it in company policy just ask my previous boss.
Contacted the OEM about the LEDs being on all the time and this is the reply.
"Syren is designed to drive an inductive load, like a motor, and not a resistive one, like an LED. So the LED will always be on."
I will continue to play with the lighting I have found a circuit that use the RC relay with a different config to what I am using so I am going to use that one.
Maybe I'll make it company policy that the front light is always lit.
You can get away with anything by putting it in company policy just ask my previous boss.
When installing a led across a motor, it will light in both directions due to the back emf output of the motor.
When a motor turns, the commutator makes and breaks contact with the power source and at this time becomes a generator from the magnetic field creating voltage when the current goes away.
When a motor turns, the commutator makes and breaks contact with the power source and at this time becomes a generator from the magnetic field creating voltage when the current goes away.