Help with Water Pump

[ronv]

And on my birthday to.

 

[KeepItSimpleStupid]

Happy BD! On the day before my BD later this month, I'm scheduled for an infected tooth extraction and hopefully implant placement.

This is great. These devices are finally getting ready to go to final test before they go into the duplicator.

Anybody want to try to persuade Joe to make real PCB's?

Joe has been amazing to work with. Congrats to everybody!

 

[salty joe]

+1 on happy BD!
KISS, I'm certainly willing to look at making a printed circuit board, but for this project at least, I don't want to get into another learning curve. It seems like something printed would have to be manufactured by a machine. Thanks for the compliment-it's been you guys willing to share your high powered know how.

 

[alec_t]

It's gratifying that most bits now seem to be working as intended. Just the LED to sort out. What voltage does your DMM show between Pump+ and Pump- when the pump's running but the LED isn't lit?

I think I'll use all new PDMs

Well at least you'll have a couple of spares to hand (hopefully not needed) . Next project back-up power supply? Or are you having a breather before considering that?

Best wishes for the extraction etc, KISS.
And Happy Birthday ronv!

 

[KeepItSimpleStupid]

@alec

Not sure what schematic we are talking about, but if it's the LED that's across the pump, maybe it needs a series diode because of the reverse breakdown spikes? It could already be damaged?

@Joe
If you happen to have a 9 V battery and something near a 10K resistor, you can put them in seres to get a 0.9 mA or so current source. Now, connect the combination to the LED and measure with your voltmeter, the voltage across the LED in both directions and report.

 

[KeepItSimpleStupid]

PCB making 101

There are two techniques used for the hobbyest and the latter seems to be doing better. 1) UV exposure and 2) Toner Transfer

Both require "artwork" from a PCB layout program.

I've done #1 using the sun and pre-sensitized boards and using professional photolithography equipment and coating, baking and exposing the boards. Resist as it's called can be negative or positive/.

You expose and develop the boards (assuming pre-sensitized) and etch with one of three systems: 1) Ferric Chloride; 2) Ammonium Persulfate or 3) A mix of Hydrogen Peroxide and Hydrochloric acid. #3 can be regenerated with an air bubbler. I've done #1 and #2.

I liked polyester paper when I made the exposeure mask and instead of a vacuum frame, I used a drop of water.

2) Toner transfer is you print the toner on paper that might release it easy. Some commercial papers, some photopapers and glossy magazine pages are used. An iron or a modified laminator (the preferred method) to transfer the toner from the paper to the board.

Drilling is tedious. A press with carbide bits is recommended.

I've done a re-flow solder thing using a frying pan and peanut oil. Alternatively there are tin plating solutions which I don't like.

Or, you can send them away to be made. No components are usually installed. A fried likes this service: http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html Just to give you an idea on prices.

Yea, another learning curve. One, that I also need to deal with. Some PCB making programs are free, but most free ones are limited in capabilities. KiCAD is an Open Source totally free program.

 

[alec_t]

the LED that's across the pump, maybe it needs a series diode because of the reverse breakdown spikes? It could already be damaged?

That's why I suggested Joe check the LED. If the PDM is powered up without the pump connected the LED should light. Or your proposed method would also do the trick.

 

[salty joe]

What voltage does your DMM show between Pump+ and Pump- when the pump's running but the LED isn't lit?
Best wishes for the extraction etc, KISS.

+1 on the tooth.

At the terminal points for the pump, with pump at a low speed I got 11.3V and on high 20.2V. The LED was not lit up at all.
0V across LED for pump on PDM with pump running.
I'll goof with it tomorror, I got some crappy little 24 hour bug that's going around.

 

[alec_t]

0V across LED for pump on PDM with pump running.

Sounds like the LED has failed short-circuit. I'd try another LED, with a 1N4148 (or whatever you've got) diode in series with it as Ron suggested. Get well soon!

 

[alec_t]

with pump at a low speed I got 11.3V

That's fine. It does, however, suggest that a 12V battery for backup of the power supply won't be enough to give you a decent pump speed for non-feed situations. At some point we'll have to re-think the backup system if you go that route.

 

[salty joe]

@alec
Not sure what schematic we are talking about, but if it's the LED that's across the pump, maybe it needs a series diode because of the reverse breakdown spikes? It could already be damaged?
@Joe
If you happen to have a 9 V battery and something near a 10K resistor, you can put them in seres to get a 0.9 mA or so current source. Now, connect the combination to the LED and measure with your voltmeter, the voltage across the LED in both directions and report.

Well, I think that LED is toast. I disconnected the PDM from speed control and hooked up the tide controller, just to make sure there wasn’t something about speed control the LED did not like. The pump toggled like it’s supposed to, but the LED is dead. When I replace the LED, does it matter which leg of the LED gets the diode? Should the anode or the cathode be connected to the LED?

That's fine. It does, however, suggest that a 12V battery for backup of the power supply won't be enough to give you a decent pump speed for non-feed situations. At some point we'll have to re-think the backup system if you go that route.

My only intention for battery backup is to keep some water moving through the filter to prevent stagnation. Two pumps at that 11.3V speed looked good to me for emergency backup. I would probably not feed at all during that time. So, if we can rig it up to run on low during a power outage, that would buy me time and that would be great.
I’d like to get a grip on the LED problem and then start emergency backup. Unless you guys would rather I made myself busy making new PDMs for a while.
KISS, the PCB looks very cool but I think I need to stay on as much familiar territory as I can at this point.
Thanks guys.

 

[KeepItSimpleStupid]

When I replace the LED, does it matter which leg of the LED gets the diode? Should the anode or the cathode be connected to the LED?

The order doesn't matter, but the direction of the diode and LED do matter. If this LED is a standard t 1- 3/4 LED about 0.200 in diameter and even smaller ones, you should notice that there is a Flat near one lead.

If the LED and the diode were side by side.

(LED +) (LED Flat) ---->|-----
LED..........................DIODE

You can transport the DIODE to either side, just don't reverse it. The series resistor can be anywhere in the string too. e.g. LEFT, RIGHT or middle.

(+) Anode, (-) cathode

It's in your best interest, I think to run one or two pumps at some lfunctionality when your around to listen for a stop.

The 11.3 V is still a problem. Thinking caps on everyone. FWIW: I though these ideal diode controllers would help. https://www.electro-tech-online.com/custompdfs/2013/02/2PB_idealdiodesf.pdf NADA.

If the diode is in wrong, the LED won't work.

 

[salty joe]

Not sure I have this right, but I think you are saying to either connect the anode of the diode to the positive leg of the LED or connect the cathode of the diode to the negative leg of the LED.

I thought the lower the voltage the pump was running on, the longer the battery would last. 11.3V was near the pump's lower limit of not working, maybe it would be a better idea to use 12V as the min V. Would that make things easier?

 

[alec_t]

My only intention for battery backup is to keep some water moving through the filter to prevent stagnation. Two pumps at that 11.3V speed looked good to me for emergency backup.

In that case a 12V battery backup will be ok. That simplifies things.

Not sure I have this right

Fraid not. The leg next to the flat on the LED body is the LED cathode (-ve leg). Connect that to the diode anode. Or connect the LED anode to the diode cathode.

I thought the lower the voltage the pump was running on, the longer the battery would last.

That should be so, though it might be better to run the pump at 12V to move it's operating point a bit above the limit of not working. It won't make much difference to the battery discharge rate.

@KISS
Yes, those ideal diodes look promising. Haven't come across those before.

 

[KeepItSimpleStupid]

@Joe
For the LED thing: Think batteries in series. Each device, the LED, resistor and diode are in series with polarities arranged so that IF the devices were batteries, the voltages add. That means + to - to + to - to + to - and you get a + and - for the entire string.

 

[salty joe]

. That simplifies things.

That's music to my ears

Thanks guys for clearing up the diode on the LED.

 

[KeepItSimpleStupid]

@ Alec
Useful?: https://www.mini-box.com/Y-PWR-Hot-Swap-Load-Sharing-Controller
Cheap enough.

 

[alec_t]

@KISS
Looks ok, providing Joe doesn't turn on all his pumps simultaneously, which would draw more than the 10A for which each channel is rated.

 

[4pyros]

@ Alec
Useful?: https://www.mini-box.com/Y-PWR-Hot-Swap-Load-Sharing-Controller
Cheap enough.

Nice little controller.

 

[salty joe]

With the tide controller at four pumps, eventually the two idle pumps are bound to "flick" at the same time the running pair start. (The running pair will run for 30 sec, off 5 sec) The wave controller will individually turn two pumps on and off all day. The filter pumps will run nonstop with speed control. So it's not hard to imagine five pumps starting simultaniously, with two more pumps running.

But I'm lost-what is that smart little controller for?