Help with Water Pump

[ronv]

You have a big battery and a low charge current so room temperature would probably be the only consideration.

 

[alec_t]

When they are running on the battery, would they only consume about half as much power?

Job to say. Motors don't behave like simple resistors. At lower volts the pump will run slower; but that means the back-emf is lower too, which counters the expected current reduction. With your DMM on its 10A range and in series with the pump you could check.

would a 70ah battery run two old filter pumps for about 54 hours?

I doubt it. The battery would probably be totally drained (and damaged) before then.

the temp will be between 50-70F, 10-21C.

It's actually the battery temp which counts, and the battery may get a bit warm as it charges. The NTC ideally should be in good thermal contact with the battery. But as Ron says, with a big battery room temperature will dominate.

 

[KeepItSimpleStupid]

The battery also gets warm on discharges too.

 

[salty joe]

The amperage when a pump is connected to the old PS is 1.13. When the pump is running on the battery, the A is 1.4. ): Does that make sense?
BTW, you guys know where the smiley faces are on this improved site?

Oops. That 1.4A is running both pumps. 0.7A/pump, that's not so bad.

So with a 70ah deep cycle battery I think I could get a day+ running on the battery.

OK, there's the smiley, nothing for an angry sad boy though.

 

[KeepItSimpleStupid]

Using 70 AH and 1.4 A,I get like 50 hours using this page. https://www.powerstream.com/battery-run-time-calculator.htm

The only way to know is to test it while monitoring battery voltage. There is info in the recent posts about what voltage will be too low to discharge the battery to.

 

[salty joe]

Hi KISS, i should have added 'without damaging the battery'. From what I've read, some deep cycle batteries cycle deeper than others.

 

[alec_t]

So with a 70ah deep cycle battery I think I could get a day+ running on the battery.

Should do that comfortably.

nothing for an angry sad boy though.

Why one of those Joe?

 

[salty joe]

I was just joking. I'm a happy boy. Usaully. I was pretty bummed for a minute when I thought the old pumps were drawing more current on 12V than 20.6V. And one or two times when I let some wires touch that had no business getting together and things fried I was angry boy. Some bad words might have slipped out. But that's all small stuff, I have so much to be grateful for.

https://www.electro-tech-online.com/attachments/74426/


I'm trying to dial in the flick by playing with C10. One 0.1uf gives me almost enough flick with the trimmer adjusted all the way. Two 0.1uf caps in parallel is a teeny bit too much flick with the trimmer adjusted the other way. These are radial caps. This cap has the value I'm looking for, but is a different type of cap. Is it likely to work here?

https://www.ebay.com/itm/10-x-0-15u...ultDomain_0&hash=item3cb9ca7c3a#ht_1379wt_866

24 hours+ on the battery is awesome!

It is so nice to be able to use the search function and type more than one line in the response box without everything jumping around. I used to go to Microsoft Word and copy and paste. Word made me look like a champion speller. I miss all the happy/sad/confused etc faces and the automatic restore, but all in all this upgrade is super.

 

[alec_t]

To save sending off for another cap could you just leave C10 at 0.1uF but replace R3 (now 150k) with ~270k-390k?
I'm still confused about some of the new site features, but hopefully we'll get all the old functionality back eventually. EM's got his work cut out.

 

[salty joe]

Thank you Alec, I'll try switching out R3 tomorrow. I appreciate that idea.

 

[salty joe]

I replaced R3 with a 390K, but don't have everything hooked up yet.
Awhile ago when I fired up the 8 new pumps I did not have the 8 diodes included as shown in the bottom left of the link. It looks like those 8 diodes on signal ground are connected to +24V. That doesn't seem right, but what do I know? Just double checking, can you please have a look?

Right now, I don't have the wave system hooked up because I just want to dial in the flick. I don't need to worry about those diodes for the flick test, do I?
Thanks all.

https://www.electro-tech-online.com/attachments/74720/

 

[salty joe]

I replaced R3 with a 390K, but don't have everything hooked up yet.
Awhile ago when I fired up the 8 new pumps I did not have the 8 diodes included as shown in the bottom left of the link. It looks like those 8 diodes on signal ground are connected to +24V. That doesn't seem right, but what do I know? Just double checking, can you please have a look?

Right now, I don't have the wave system hooked up because I just want to dial in the flick. I don't need to worry about those diodes for the flick test, do I?
Thanks all.

https://www.electro-tech-online.com/attachments/74720/

 

[alec_t]

The 8 diodes (they're not connected to ground!) provide the multiple redundancy you requested for the 24V input supply voltage to the 12V regulator. As long as at least one of the 8 new power supplies is operating the 12V regulator will get its 24V input (minus 0.6V dropped by the respective diode). So you do need to worry about the diodes (well, at least one of them). No 24V input = no 12V output = no flick, no nothing.

 

[salty joe]

Thanks, those beefy diodes are all hooked up. I thought I missed something. Hope to test flick tonight.

 

[salty joe]

I hooked up the tidal system but all four new pumps ran. The tidal timer seems to be toggling from 3.1V to 15.0V. There is 15.0V at the 12V terminal points. Leg one ofthe 7812Vreg is 23.7V, leg two is 3.1V and leg three is 15V??? I checked and it is a 7812. Last time I hooked it up, it ran like a champ...ugg. Bad Vreg? The only change I can think of is the 390K at R3 in TPASM and I disconnected one of the two 0.1uf caps in paralell at C10. I'll double check that the polarity is correct at C10 in the morning. I'm pretty sure all connections are right, but I'll double check.

On TPASM, I have a row of signal ground terminal points for distribution. I have a seperate row of terminal points for power ground. Should I run a wire to connect the row of power grounds with the row of signal grounds?

 

[KeepItSimpleStupid]

Check for a bad ground connection on the regulator. Try ohmmeter with the system off.

Ideally signal and power ground for everything should connect at one point, the power supply (-) terminal.

If this is your point of distribution, then power and signal should be connected together there.

This could be the problem with the 7812.

 

[alec_t]

Leg 2 of the 7812 reg should be 0V, so there is a grounding problem. The reg puts out 12V above the leg 2 voltage, hence if leg 2 is not 0V you get the wrong voltage (in this case 12+3.1). The reg itself seems ok.

Should I run a wire to connect the row of power grounds with the row of signal grounds?

Yes, as KISS says. They must go to a common point (as per the star grounding arrangement I posted) connected to mains earth.

 

[salty joe]

Thanks KISS and Alec. I'll try that tonight. Fingers crossed.

 

[salty joe]

You guys nailed that one-thanks a million! The tidal system is back to working like a champ.
I spliced into gound of two of the cords feeding the new PSs and sent one to signal ground and the other to power ground. I guess I'll splice into ground on all 8 cords feeding the new PSs and send 4 to power ground and 4 to signal ground, for redundancy.
The flick is a bit much with 390K at R3 and 0.1uf at C10. I don't have anything between 150K and 390K. So I'm thinking of going back to 150K and trying this 1.5uf cap unless it's not a good cap for the job. I ordered it late last week.
**broken link removed**

Thanks again, you guys made my day.

 

[KeepItSimpleStupid]

Joe, two 390K in parallel is (in my head) 150+45 or 195K. Remember that formula works for same value resistors.

You can also try, two 0.1 uf caps in SERIES to get 1/2 the capacitance or 0.05 uf. In parallel, 2x the capacitance 0.2 uF.