Help with Water Pump

[alec_t]

If you haven't already found the bug here's the green LED fix (hopefully!):-
**broken link removed**
This trimmer needs to be adjusted with the battery disconnected, with either or both power supplies on, and with R1 temporarily shorted across so that VinU1 = +Vext. Set the trimmer such that the voltage at the inverting input (marked x) of the opamp is ~50mV greater than the voltage at the non-inverting input (marked y). If you don't yet have the NTC 68k resistor use a 100k ordinary resistor for now.

 

[salty joe]

Thanks Alec.
My computer did not notify me so I did not see your reply until now. Sure am glad I checked in.
I get an invalid message from the attachment. In a little bit after I'm done cleaning the kitchen, I'll contact the administrater.

 

[KeepItSimpleStupid]

@Joe
I get the error too.

]The forum has some wacky algortithm about wheter to notify or not. You REALLY have to visit the forum to "re-read" a message to be guaranteed notification. Don't just read it in your email.

 

[alec_t]

Try again....

 

[salty joe]

Got it-thanks.
I'll get after it tomorrow.

 

[salty joe]

I installed the mod for the LED charging indicator-looks good so far. The LED is off. I recently charged the battery so I'll let the pumps run the battery down a little and turn the PSs back on and see the LED come on.
Thanks for another fix.
Is this the part we want for R9?
https://www.digikey.com/product-detail/en/ERT-J1VA680J/P10535CT-ND/269390
Thanks a bunch.

KISS, I always visit the site. I think my computer is squirrelly and getting worse. I better back up my pics!

 

[alec_t]

looks good so far

Good. Setting the trimmer was probably a bit fiddly?

Is this the part we want for R9?

Similar sort of thing, but 68kΩ, not 68Ω

 

[salty joe]

The trimmer was not too bad to set. I got 15.31V on X (pin 13) and 15.82 on Y (pin 12).

Thanks for catching that 68K!

 

[alec_t]

I got 15.31V on X (pin 13) and 15.82 on Y (pin 12).

Should be the other way round, i.e. volts on pin 13 > pin 12

 

[salty joe]

oops
I'll adjust it tonight. Thanks. I better tighten up.

Last night, I ran the pumps on the battery for 45 minutes. When the PSs were plugged back in, LM317 on the heat sink got just warm to the touch and there were 12.76V at the battery terminals.
I let the filter pumps run all night. LM317 is just barely above room temp and there are 13.23V at the battery terminals.

 

[alec_t]

So the LM317 is doing its job. Good that it's not getting too hot. It will take quite a while to fully charge the battery. In theory the charge rate starts off at ~ 0.5A then drops slowly down to ~50mA, at which point the green LED should go off, marking the end of the bulk charge. Charging then continues as a trickle.

 

[salty joe]

Yes, I was happy, really happy, not to have an issue with heat.
With battery disconnected, I took a quick reading before work and X (pin 13) adjusts from 15.11-15.76V. Y (pin 12) remains at 15.85V. At this point, I can't give X more voltage than Y.

 

[alec_t]

If you've 'run out of trimmer adjustment' it's likely because of resistor tolerances. A 1k resistor (or the closest value, <2k, you have to hand) inserted between the end terminal of the trimmer and the top of R11 should solve that and allow the pin 13 voltage to be set higher (15.85V + 0.05 V).

 

[salty joe]

Thanks Alec.
I installed a 1K between R11 and the trimmer. With the battery disconnected, the adjustment range for pin 13 is now 15.22-15.85V. So close..

Edit:
I replaced the 1K with a 1K5 and the max V at pin 13 is now 15.90V. I'm letting the pumps run on the battery while I eat dinner, can't wait to see if we got it.

Edit:
I let the pumps run down the battery for 40 minutes and still no indicator light when the PSs are turned on. The LM317's heatsink got considerably warmer, borderline hot. Not hot enough to raise a blister but hot enough to be uncomfortable to touch. Could the increased heat have anything to do with the 1K5 resistor added between R11 and the trimmer?
Everything's shut down for now.

 

[alec_t]

The 1k5 should be ok.

Could the increased heat have anything to do with the 1K5 resistor added between R11 and the trimmer?

No. The 317 will be hot when its pushing 0.5A + into the battery, since it's then dissipating ~ 0.5 x (21-13) = 4W. It's built to cope with more than that and has internal temperature and current limiting. Can't recall how big the heatsink is, but if you could bolt on a bit of extra metal sheet to extend it that would would drop the temperature. Don't forget the heatsink is at power supply voltage, not ground.
As for no indicator light, you did remember to remove the temporary short across R1?
What voltages do you get at pins 12, 13, 14 of the LM324 when the battery is charging?

 

[salty joe]

With the battery charging, there were 15.83-15.84V at pin 12, 15.75-15.76V at pin 13 and 0.94-0.95V at pin 14.

After your last post I realized that I never did short R1. Sorry. So I disconnected the battery, jumped a wire across R1 and got pretty much the same numbers. 15.83 at pin 12 and 15.89V at pin 13.
When I removed the jumper, connected the battery and plugged the PSs back in, the pumps did not run. No pump LEDs no nothing. With the PSs turned off, the pump lights and the red 'battery in use' LED came on, but the pumps did not run.
I thought maybe it affected the filter pump timer so I pushed the ‘on’ button to no avail.

Any chance you could help sort this out?

 

[alec_t]

With the battery charging, there were 15.83-15.84V at pin 12, 15.75-15.76V at pin 13 and 0.94-0.95V at pin 14.

Something fishy at pin 14. If pin 12 > pin 13 (as it should be when charging at 0.5A) then pin 14 should be > 10V.
1) Double-check the connections to/around the LM324.

When I removed the jumper, connected the battery and plugged the PSs back in, the pumps did not run. No pump LEDs no nothing. With the PSs turned off, the pump lights and the red 'battery in use' LED came on, but the pumps did not run.

2) Can you confirm the battery was re-connected with the correct polarity?
2) Are any of the fuses blown?
3) With the battery disconnected and the PSs powered up what volts do you get at the points labelled Pump+1, Pump+2, +12.6 in the FPPB-Mk2 and PDMs?
4) With the PSs both off and the pumps connected what is the battery terminal voltage?

 

[salty joe]

Thanks Alec. I have a couple long days ahead, if you could wait until then for me to tackle this, I'd appreciate it. Thanks for the diagnostics.

 

[salty joe]

I temporarily connected pin 4 to 12.6V and everything came to life. Tomorrow, I'll look into +Vext.

I pulled the negative wire off the battery and it slipped out of my hand and touched the positive terminal (the positive wire was still connected to the battery) for a split second. I heard a faint crackle and saw a tiny puff of smoke. I think it came from the LM317. Everything still seemed to work, but the LM317 got hot in a hurry. I think it might be toast, can you tell me how to test it? I have a couple more LM317 and it should not be hard to replace.

 

[alec_t]

I temporarily connected pin 4 to 12.6V and everything came to life.

If you mean pin4 of the LM324 that was risky: if either PS was on at the time it put ~ 20V on to the 12.6V rail

I pulled the negative wire off the battery and it slipped out of my hand and touched the positive terminal (the positive wire was still connected to the battery) for a split second.

That sounds like you 'just' shorted the (disconnected) battery. If so it's unlikely to have harmed anything else. It would probably also mean that the '317 was then running flat out to charge up the battery, accounting for it getting hot quickly.

Everything still seemed to work, but the LM317 got hot in a hurry. I think it might be toast, can you tell me how to test it?

Disconnect the battery +ve (c-a-r-e-f-u-l-l-y ).
Until the filter pump power supply issues are resolved it would be best to keep the PDMs of the two filter pumps disconnected.
Measure the volts at the points labelled Supply+1, Supply+2, +12.6. You should get ~ 20, 20 12.6, respectively.