Help with SES-II and/or Caswell pump controller

[bob the builder]

Good morning, all!

I've got a cylinder that I'm building right now for my 48th Type VII and I'm running an air pump that is controlled with the Caswell (KMC Designs) control unit. I also have a vent that is actuated by a solenoid. The solenoid draws too much amperage for the built in controller on the pump circuit board, so I'm running an SES-II to control it.

The issue I'm having is that the stick direction for activating the pump and for activating the vent are both in the same direction. Basically the same stick direction activates both functions in one direction and nothing happens in the other. I need to reverse either the SES or the pump controller, but I have no idea how to do it without the use of an additional servo reversing module. For now I just have the two functions on a different channel. Worst case I can do that long-term as I have channels to spare, but it's a bit messy and I'd like both functions to be carried out on the same channel.

Any idea how I can reverse throw on either module?

Thanks.


Bob

[bigdave]

Bob
I think Kevin's control unit has a reversing switch, or maybe that's a fail safe switch.
Interesting problem though.
Kevin is the one to talk to. Good luck. BD

[bigdave]

Actually thinking about it, it should be simple.
Both devices are two separate switches.
So just use the other switch on one of the units.
There are three outputs on the SES2.
Ground, hot, hot.
Just use the other hot. You can assign the failsafe side on both devices.
Unless I am under thinking it that should work for you. BD

[bigdave]

I think they switch the grounds in the SES2 so it would be Ground Hot Ground.
It's been a while. BD

[JWLaRue]

What BD suggested is exactly what I did with the SES-II for my home-grown wet RCABS system.

-Jeff

[bob the builder]

I'm afraid I'm not understanding what you had in mind, guys. The SES switch that I have has two jumpers, one for momentary/latching and one for the failsafe on/off. There are only two outputs with screwdown terminals. It could be that it's actually an SES-3 (must be, now that I think of it).

I see that Caswell sells a SUB ES2 switch that would be perfect for this application. If I just yank the pump board from the back of the pump, I can use this single module to control both functions. Might go that route...

[JWLaRue]

Bob,

I can send you a scan of the SES-II instructions if you'd like.....?

-Jeff

[bigdave]

Mine is a two position electronic switch.
Center off and either way turns on one of the two switches.
It had three screw down connections for connecting the pump or valve.
Center (plus) connects to both devices, and one ground from each device.
If your joy stick or three position switch is in the center both devices are off.
Moving the stick either to one end or the other turns on the device.

[KevinMC]

Good morning, all!

I've got a cylinder that I'm building right now for my 48th Type VII and I'm running an air pump that is controlled with the Caswell (KMC Designs) control unit. I also have a vent that is actuated by a solenoid. The solenoid draws too much amperage for the built in controller on the pump circuit board, so I'm running an SES-II to control it.

The issue I'm having is that the stick direction for activating the pump and for activating the vent are both in the same direction. Basically the same stick direction activates both functions in one direction and nothing happens in the other. I need to reverse either the SES or the pump controller, but I have no idea how to do it without the use of an additional servo reversing module. For now I just have the two functions on a different channel. Worst case I can do that long-term as I have channels to spare, but it's a bit messy and I'd like both functions to be carried out on the same channel.

Any idea how I can reverse throw on either module?

Thanks.


Bob

Hi Bob!

Wow, I feel late to the party here. Unfortunately reversing the control of pump and solenoid is not one of the programmable features of the PSC. How much current does your solenoid draw? How long do you expect to be holding it ON for? If worst came to worst, you could drive a small relay from the PSC and your solenoid off the relay contacts, but before jumping to that help me to better understand what you've got...

KMc

[bob the builder]

All good, guys. I just used a little MERS switch to drive the solenoid. Unfortunately it draws more than the 0.5Amps tat the controller can handle, so a separate unit was needed.

Thanks for the help, everyone!

[KevinMC]

Unfortunately it draws more than the 0.5Amps tat the controller can handle, so a separate unit was needed.

How much more does it need? (This is good data for me to have at hand if I roll that design up to a larger FET...)

[bob the builder]

The one I was using had a spike at 2A and a normal pull of around 0.65A. Your rating is probably okay. I was just using a beast of a solenoid because it's what I had here.

[KevinMC]

Hi Bob,

Thanks for the info - that backs up my previous thoughts that if I do an update to this board I should be looking for at least 1A (nominal) current draw.

It's a pretty small FET that drives that circuit on the existing board - you're right to be concerned. I want to say it would probably handle it, but you'd definitely be pushing the limit. Out of curiosity, does the solenoid need that much power to throw, or might it be able to still do it's thing with an inline resistor to knock down the current just a little?

[bob the builder]

Good question. I would assume it would still be good. It only pulls about 3/16" so it could likely do with less power. I'm not worried as I have it all rigged up and working perfectly with that secondary switch unit. No harm, no foul... All is good!