Point motor switches

samesame
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Re: Point motor switches

#11

Post by samesame » Mon Feb 11, 2019 6:45 pm

Sorry Brian I didn't see your post before I posted the capacitor/ diode diagram which I think is essentially the same as yours. Thanks again.

Ron S
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Re: Point motor switches

#12

Post by Ron S » Mon Feb 11, 2019 7:35 pm

As I said in post #5, I use the one-wire circuit that Brian posted in #9 but with a minor change, all capacitors are 2200uf & if two solenoids as one like a crossover, then I make it 4700uf and always use a 19v DC supply.
All solenoids now have either the Peco accessory switch or a microswitch to operate LEDs on the panel. I have found that LEDs opearted by the toggle saves wiring but it has been known for the toggle to show a direction but the solenoid has not moved for some reason.
Turnouts frogs are basically dead frogs ( similar to Unifrogs)

The 19v supply - I use one like this
https://www.ebay.com.au/itm/19V-3-95A-A ... ctupt=true
Ron

NCE DCC, 00 scale, very loosely based on GWR

samesame
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Re: Point motor switches

#13

Post by samesame » Thu Feb 14, 2019 2:09 pm

Hello again

So I decided to go with the one wire design (thanks Brian for the diagram) and set up a test rig. I am using a Seep PM1 point motor and a centre off SPDT toggle switch (this was what I had to hand). The nearest capacitor I could find on the Rapid Electronics site was a 1000uf 50V version. The power supply is a laptop charger producing 20V DC.

For some reason the motor will only throw roughly half of the distance between the solenoids which isn't enough to switch the point. I understand that it should throw the full distance.

Does anybody know where I'm going wrong?

samesame
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Re: Point motor switches

#14

Post by samesame » Thu Feb 14, 2019 2:18 pm

As I said in post #5, I use the one-wire circuit that Brian posted in #9 but with a minor change, all capacitors are 2200uf & if two solenoids as one like a crossover, then I make it 4700uf and always use a 19v DC supply.
Hi Ron S. Only just saw your post. Do you think I need the higher rated capacitor to fix this problem?

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Brian
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Re: Point motor switches

#15

Post by Brian » Thu Feb 14, 2019 3:06 pm

Hi
1000uF should be OK though larger values will give a greater whack! Try the Seep off the point/layout in free air. Does it 'pop' over and back both ways?

To double check... The Negative lead of the electrolytic cap is to the point motors diodes commoned together connection. The two diodes (one on each coil) are connected inverse to each other, so as the banded end of one diode is towards Seep A tab and the unbanded end of the other diode is on B Seep terminal. The capacitors positive lead is wired directly to the SPDT switches middle tab. switches outer tabs have the DC Positive and Negative on them. Tab C on the Seep goes to the Negative of the supply which is also to one tab on the operating switch too.

User problems with this circuit is the one main reason I removed the circuit from the web site, when the site was re written with new software.
Image << Click the Icon to go to my website

samesame
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Re: Point motor switches

#16

Post by samesame » Thu Feb 14, 2019 5:13 pm

I've checked all the polarities and they are as you describe. The problem persists with the motor unmounted in free air.

I've copied the wiring set up on this video:

https://www.youtube.com/watch?v=041Ji8zBMIw

Would soldered joints be better than a connecting block?

Ron S
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Re: Point motor switches

#17

Post by Ron S » Thu Feb 14, 2019 9:39 pm

Use a 2200uf capacitor as shown in the video or if you have another 1000uf , add that in parallel with the existing 1000uf. And the terminal strip is OK.
Ron

NCE DCC, 00 scale, very loosely based on GWR

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Brian
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Re: Point motor switches

#18

Post by Brian » Thu Feb 14, 2019 10:37 pm

Unfortunately Seep PM1 to PM4 solenoid motors are exceptionally power hungry! Also they are in need of very careful fitting to the baseboard/point above to ensure correct operation.
If yours do not operate in one direction in free air and all tests prove correct as outlined in the message above, then either the power supply is not providing the voltage and current needed or the capacitor is not providing sufficient punch to operate the motors coil.
Please be aware that at least 2 seconds should elapse between switch operations to ensure the capacitor reaches fully charged condition.
Image << Click the Icon to go to my website

Ron S
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Re: Point motor switches

#19

Post by Ron S » Thu Feb 14, 2019 10:50 pm

And to add to Brian's reply, the initial charging current is high as Peco solenoids need around 2-3 amps to be effective especially if their accessory switch is added. The discharge of course for the other direction movement is good as long as the capacitor value is better than 1000uf and the solenoid moves freely.
Ron

NCE DCC, 00 scale, very loosely based on GWR

samesame
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Re: Point motor switches

#20

Post by samesame » Sun Feb 17, 2019 11:29 pm

Upgraded the capacitor to 2200uf and everything works fine.

Many thanks for all your help.

By the by, I have managed to retrofit the point motors to the already ballasted layout by back drilling. You drill a small navigation hole two sleeper gaps along and then measure back. I was worried that the drill would trash the tie bar but if you use a depth guard and take it slowly it works. Just thought I would mention it as most of the tutorials I have watched or read say that you have to drill the hole before you fit and ballast the point. Obviously better if you can but all is not lost if you are retrofitting.

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