Help with Water Pump

[salty joe]

If you are going to order parts you might pick up a few 1Ufd. caps like these:
https://www.mouser.com/ds/2/40/skycap-sr-8826.pdf
and some 100 ohm resistors. This is a just in case if one of the modules starts to oscillate like the fussy pumps.

In that link, there are 1uf caps listed under x7r and z5u. I could not find 1 ufd.

I ordered everything for your charger except the just in case 1uf cap.
Would one of these 1uf caps work?

multilayer monolithic 50V
radial tantulum 35V
radial elecrolyt 50V
5% polyester box type 100V
Thanks.

 

[alec_t]

If this is intended for a snubber then I'd go for the 100V poly type. BTW 1ufd = 1uf = 1 microfarad.

 

[KeepItSimpleStupid]

Here is a good Mouser p/n: 667-ECQ-V1J105JM which is specifically designed for pulse applications.
Yep, the polyester type or metalized polyester.

 

[ronv]

Yes, either the multilayer or the poly, whichever is cheapest.

 

[salty joe]

Thanks guys, the poly caps are on the way. I can hardly wait for the parts for speed control to get here. When I was a kid I used to feel the same way waiting for stamps from H. E. Harris.

 

[KeepItSimpleStupid]

So, are you doing any testing at all at this point?

Joe: As you found out, not all capacitor types are equal. If you ever run into a high voltage oil filled cap (not likely), don't ever touch both terminals. They actually have to be stored with a "keeper" on them. The "keeper" is a short across the terminals, otherwise the cap can bite you.

 

[salty joe]

No testing yet- the parts to finish speed control should be here any day. Then I'll tie everything together and see how she runs.

 

[4pyros]

When I was a kid I used to feel the same way waiting for stamps from H. E. Harris.

I used to do that too.

 

[salty joe]

The parts for the speed control arrived. Won't be able to solder until probably Sunday, but Sunday for sure.

 

[4pyros]

Good luck standing by.

 

[salty joe]

Thanks.

 

[salty joe]

For speed control Mk3, I have two pulse delay sections and one speed set section on the same board. (Only two pumps will have speed control)
In the pulse delay setions, I used pins 5 and 10 from IC LM324 for ref. Can I connect pins 5 & 10 together and take that directly to the ref of the speed set section?

Can I do the same sort of thing with spd?

 

[alec_t]

Can I connect pins 5 & 10 together and take that directly to the ref of the speed set section?
Can I do the same sort of thing with spd?

Yes and yes. Both pumps should then run at ~ the same speed.

 

[salty joe]

Well I hooked everything together, but I must have a connection wrong or something. The two alarm LEDs I have hooked up came on immediately, but the piezo did not sound. The pumps did not run at all. I'll start going over it tomorrow. I ran 12V to Vt of the PDM for non-stop pumping.

I noticed the fault sensor has Vt connections, one for each pump. Except for the wave pumps, I was going to use a single Vt per two pumps because the tide and filter pumps are run as pairs. I left the Vt connections from the fault sensor disconnected. The working pair of PDMs has a single Vt terminal point. Oh well, darn it.

 

[alec_t]

Well I hooked everything together, but I must have a connection wrong or something

Double check; particularly the +V and ground connections of all modules/sections.
Do you now have the Vt and Fault inputs of U1d in the PDMs connected to the Fault Sensor (I think they were temproarily grounded previously)?
What voltages are at the Spd and Ref terminals of the Speed-Set Section (when the SetMax and SetMin trimmers are each about mid-setting), and at the output of U1b in the Pulse Delay Section section?

The two alarm LEDs I have hooked up came on immediately, but the piezo did not sound.

That's odd, if the alarm section is as shown in theTPASM schematic (albeit with only 2 alarm inputs). If either LED is on the voltage at Q1 collector in that section should be close to 0V. Check that. How much current does you alarm beeper need?

The pumps did not run at all.

Which would account for the alarm LEDs being on.

I ran 12V to Vt of the PDM for non-stop pumping.

Fine.

I was going to use a single Vt per two pumps

Fine. Vt1=Vt2=Vt for the pair.

 

[salty joe]

On my pair of PDM15s, I tied all Vt connections together to a single terminal point. I ran 12V to the PDM Vt and the fault sensor module Vt. All the connections look good. I feel confident that nothing is mislabeled.

With max & min trimmers at about 12.5K, spd is 7.39V, ref is 0.09V, output of Ub1 is 2.58-2.63V.

I had the piezo connected backwards. Duh.

With 12V ran to the fault sensor Vt, the pumps still did not run. They did make a hum, but it was not the same hum sound as before we installed that 2K2 resistor on the PDM. After 5-10 seconds, the piezo started screaming. PDM trimmers are set about halfway.
Thanks.

 

[alec_t]

spd is 7.39V, ref is 0.09V,

As per design √.

output of U1b is 2.58-2.63V

Surprisingly low. I would expect > 9V as measured by a DMM.

I had the piezo connected backwards

That would make a difference .

the pumps still did not run. They did make a hum, but it was not the same hum sound as before

With only 2.6V (avg) on U1b output the FET isn't turned on for as long and/or as much as before, so the hum is different and the pumps aren't getting enough oomph to get them started.

After 5-10 seconds, the piezo started screaming. PDM trimmers are set about halfway.

Looks as though the alarm section works as intended. Presumably the alarm LEDs lit at the same time as the screaming started?

Next test: What voltages do you get at (a) the output of U1a in the Pulse Delay Section and (b) the junction of R3/R4 in that section?

 

[salty joe]

In the pulse delay section, the output at U1a is 9.1V and R3/R4 is 6.12V.

I double checked the output at U1b and got around 2.75V at D1 or D2 cathode. I have two pulse delay sections and got the same reading on both IC cornerpin/D1/D3 cathode junctions.

Thanks for the testing.

 

[alec_t]

Maybe the FET is oscillating again. Try connecting the anode of D1 (i.e the SpeedCon output of the delay section) via a 2k2 resistor (instead of directly) to the SpeedCon input of the PDM.

 

[salty joe]

I soldered a 2K2 on the speedcon wire between the pulse delay section and the PDM, but it did not seem to make any difference.
BTW, the alarm sounds after 5-10 sec. even if no pumps are hooked up.