Motor Circuit - Page 1
Forum section: electronics / beginners

author: Thejmr
author_rank: Newbie
timestamp: May 28, 2015, 11:14:26 am
content: Hi everyone this may sound a very strange one, HoweverI have model railway and the points are powered by motors at 24volts via an arduino powering relays. etc. All my motors work but one of them. If i connect it like the diagram the motor i guess is shorting as it tries to fire in both directions at once take one return off and the motor works. Before i have to go to the trouble of replacing the motor I am wondering if there is anything out there that could help fix the issue. I'm not the best at all this but i use google and learn as I go.Please find attached the diagram in the leaflet that is provided with the motor.only differences areon the last image on the bottom of the last page.The 16volts is 24volts there is no CDUand the PL26 is a Relayall the other motors work fine its just this onesorry to be a pain

author: Cliff Matthews
author_rank: Unknown
timestamp: May 28, 2015, 11:51:37 am
content: You mentioned both directions at once - if the shaft was vibrating, it could just mean the motors run AC (switched by DC relays). Have you swapped this motor with one of the others?

author: Thejmr
author_rank: Newbie
timestamp: May 28, 2015, 12:34:09 pm
content: yes I have swapped the motor and its works with other motors its just this one motor.

author: Cliff Matthews
author_rank: Unknown
timestamp: May 28, 2015, 06:25:11 pm
content: You have a volt meter? (Just a little more info can guide folks to give better answers)Are your relays sending AC or DC to the motors? Also without power, does the problem motors shaft turn by hand? If so, does it sound and feel like the others?The commutator and brushes should be smooth (it shouldn't grab when you turn the shaft). If you have no experience talking apart a motor, don't until you know what you're getting into...Tons of vids on YouTube - Example:Your 24v motor's likely much larger but you get the idea... re-assembly can be tricky.

author: ignator
author_rank: Regular Contributor
timestamp: May 28, 2015, 08:21:53 pm
content: Quote from: Thejmr onTodayat 06:14:26 AMI'm guessing the CDU is a bridge rectifier. As from the instruction, it appears to me to be a solenoid 'motor' that is throwing the track turnout mechanism.And your driving it with AC, but you need DC, if my belief is the CDU is a rectifier. It probably has a current limit resistor in the circuit as well to prevent diode or solenoid winding damage.

author: MarkF
author_rank: Super Contributor
timestamp: May 28, 2015, 08:56:26 pm
content: These don't look exactly like motors but back to back solenoids. Do the working ones snap from side to side when energized or is there a worm gear moving the turnout shaft?I would get a meter and check that there are no shorts between the coils on either side. Also try taking the unit out of the circuit and jumper power to each coil independently.

author: C
author_rank: Super Contributor
timestamp: May 28, 2015, 09:40:24 pm
content: CDU = Capacitor discharge unitPL-10 in your attachment is a dual solenoid motor.Two coils of wire or two electromagnets.In the picture you have two wires to the right that go into the black area, that is one coil/ electromagnet.You have the same on the left forming a second electromagnet.The right electromagnet moves the points one direction, the left electromagnet moves the points in the other direction.Only one electromagnet should be powered for a short time. Power both and they fight.Test for PL-10connect one electromagnet's two wires to the two wires of your 24 V ac supplyRemember short time, 1 second or less is enough.the points should move one way ( the bar that sticks out of your points motor should move to one end)repeat test using other two wires.Note: will not move bar if it's already at that end.Just guessing now think you have relay problem or wiring problem.C

author: C
author_rank: Super Contributor
timestamp: May 28, 2015, 10:07:06 pm
content: PL-26One relay will not do the job. It would leave power connected all the time to your points motors, not good -- points motors,burn up.PL-26 is a momentary single pole, double throw with center off switch. This equals two relays, one to open points, one to close points.For many turnouts or points as you call them, you could have one direction relay and then one relay for each turnout/point so that you can power it for a short time.C

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 28, 2015, 10:45:03 pm
content: Quote from: C on May 28, 2015, 10:07:06 pmAnd, pulling the track switch/points with a passive spring isn't very positive, and will waste even more energy when the solenoid is pulling against it. Many good reasons to use a pair of solenoids, one for each position. And the magic box probably contains some capacitors to give the solenoids some extra "boost" to change the switch, but then pass no significant current after the action.

author: Thejmr
author_rank: Newbie
timestamp: June 04, 2015, 08:58:43 am
content: wow I got a lot of replies. the relay switches on for 250ms then off.As C said currently this motor when fully wired up they are fighting with eachother and therefore going no where fast.C I can provide a Video of what is happening and the wiring if this would help.