Help with Water Pump

[alec_t]

It would have been better if you had started your own thread for that topic.
If you are asking how to reduce the voltage from an OEM controller of the type provided by the pump manufacturer then the answer would be to change the ratio of the resistors forming the voltage-divider which feeds back a voltage to pin 4 of the 2576 regulator IC in the controller.

 

[alec_t]

Tried file upload. Still not working

 

[KeepItSimpleStupid]

If the uploads don't work, you can email me the files and I'll upload them to a Cloud so we can all have access to them. I can then PM everyone the link to the Folder.

 

[salty joe]

Thanks KISS, 5 schematics are on the way. I heard of a cloud, but not at all familiar with them. Very cool-thanks.

 

[alec_t]

Yes, the cloud could be handy, KISS, until EM gets things fixed. I've just emailed Joe an updated schematic of the speed control.

 

[4pyros]

I can see them in the clouds thanks.
and Happy New Year

 

[KeepItSimpleStupid]

Speed Module Mk_3 (SM_Mk_3) uploaded to Cloud. Looks like the order is, "as uploaded" rather than alphabetical. You can check Properties for the file name. On this file I incorporated the date in the name.

Joe says.

Here’s the latest speed module. I had to order a few parts. Oh well, in the meantime I can see if 10.3V to the controller will drive the pumps. If it does, then 12V certainly should. It’s my understanding that 12V makes a backup easier.

---

Joe:

Backup may be trickier because of the 12 V supply and only backing up 2 pumps although it remains to be seen. Backing up two pumps instead of 4 makes the run-time longer. 4, because 2 out of the six pumps are always off.

Happy New Year everybody!

 

[alec_t]

Backup may be trickier because of the 12 V supply

I think 12V backup (assuming that 12V gives enough flow) would involve little more than a battery plus a hefty diode plus a trickle charge, providing a fully-charged battery is used initially.

Edit: Happy New Year, guys. Less than an hour to 2013 for me.
BTW I've just noticed that the Cloud images have changed from gif to jpg format. Can that be avoided or is it yet another Microsoft 'feature' which we have to accept?

 

[KeepItSimpleStupid]

@ alec

A slight misinterpretation. "The 12 V supply" meant with the the shared 12 V linear regulator.

Any number of complications could arise: e.g. having to make that a buck-boost regulator, because Vgs is too low at 8V which migh be a battery cut off.
Sorry 'bout that.

 

[alec_t]

Any number of complications could arise: e.g. having to make that a buck-boost regulator, because Vgs is too low at 8V which migh be a battery cut off.

Hmm. As the backup will only be for the two filter pumps which run continuously I think the PDMs and the Speed Module (and possibly a Fault Module) associated with them would get by on a tad less than 12V, so I hope a buck-boost reg would not be needed. I was hoping we could use steering diodes to route supply voltages appropriately. I'll play with a sim or two and see how voltage-dependent those modules are.

 

[KeepItSimpleStupid]

@alec
Assuming you used a 7812, your already down 2V. So, at a minimum you should change to an LDO regulator.

Drop in switching regulator replacements such as these https://www.electro-tech-online.com/custompdfs/2012/12/526428.pdf exist. Note possible protection required.

This website https://www.gravitech.us/312v1aswvore.html (different part#) is useless unless you like pretty pictures. e.g. You have no idea if it's buck-boost.

PS: I forgot ronv. A very important contributor. I PM'ed him with the Cloud URL.

 

[ronv]

Thanks KISS. I got them. I'll try printing them when I'm on the other computer.

Happy new Year!

 

[ronv]

If the speed control works on on 12 volts I think something like this would work for backup. The only loss is the diode drop. It will be slow to charge a large battery but hopefully the power won't fail every other day.

You set the voltage with no battery attached. Then hook up the battery.

 

[ronv]

[quoe[Edit: Happy New Year, guys. Less than an hour to 2013 for me.
BTW I've just noticed that the Cloud images have changed from gif to jpg format. Can that be avoided or is it yet another Microsoft 'feature' which we have to accept?

The image looks better if you right click it and select view original.

 

[KeepItSimpleStupid]

I just double clicked it in FF and it was fine.

Seems like ronv can attach pics. I havn't tried.

 

[ronv]

I have always used .png. Maybe it doesn't like gifs.

 

[KeepItSimpleStupid]

The images didn't change from .gif to .jpg. I got them from Joe as .jpg's. All I did, is "Save Image As" and I had no other choices but a .jpg. Agreed, GIF is a better format for non-picture images.

Latest speed module in .jpg

 

[KeepItSimpleStupid]

Latest speed module in GIF

Works for me!

 

[alec_t]

Hey, you guys can now attach pics! I'll try attaching a pic of how I envisage a simple backup arrangement might be (Joe, don't build it yet ).


Edit: Tarrah! Upload now seems to work for me too!

 

[ronv]

There may be a couple of problems with the circuit. (I think)
The 12 volts will try to be powered thru the trickle charge resistor during normal operation. Not knowing the exact 12 volt current draw the battery voltage could try to go to 20 volts - the battery would hold it down to about 15 or so - this will eventually overcharge the battery causing gassing. Or if the draw is high enough the 12 volts will be supplied thru the regulator. But in this case the battery will only be charged to 12 volts which is only about 50% of capacity.
The circuit I posted gets around these problems by setting the charge voltage to 13.6 volts which is a safe float voltage and at 13.6 volts the battery is fully charged.