Fishin boat aerator timer

[GT1000000]

Hey,
New NOOB here. I want to make a timer circuit, that I can waterproof, to control the on-off cycle of a 12 volt DC, 3 amp or less motor.
It is the aerator pump for the livewell of a fishing boat. I would like to be able to have the pump come on for 30 seconds-2 minutes, then shut off for about 5-15 minutes.
As far as waterproofing, I intend to seal it up in silicone caulking or some such material. Even though it probably won't get wet, it is in a boat and the possibility always exists...
Thanks in advance for any help or suggestions.
BTW, I know a little something, something about electronics, but only as a dummy.
Please, dumb down your explanations, although if you link me to a circuit diagram, I can follow that pretty much OK.
I would also like to keep the whole thing under 2 inches square, if possible.
gus

 

[Dragon Tamer]

Once again, this problem can be solved with a simple but reliable 555 timer circuit. It will easily run off of the 12V DC you supply to it and can controll the motor using an external current booster like a relay or a MOSFET.

I have attached a circuit that can illistrate the principal to you. The circuit will change states once every 7 to 8 minutes there about and the relation to on off time can be adjusted with the pot connceted to pin 5.

Sorry for the slopieness of the circuit, I didn't have any CAD programs to make it so I did it with MS paint isntad.

Your can play around with the RC network used for timing and can see if you get a better time constant 1.44*R*C= time in seconds

 

[GT1000000]

Thanks Vince, that should work just fine. I do have a couple of questions. I need some clarification on certain parts of the circuit. 1- V+ can be the same 12V battery voltage that I am using for the motor? and 2- the transistor? just below the Motor, IRL 3103, is that a TO220AB? 3- Obviously I will need to mount the 3103 on a heat sink?
Again, thanks, gus

 

[KMoffett]

If you don't want to start from scratch:https://www.vellemanusa.com/downloads/0/infosheets/datasheet_vm188-uk.pdf
Can't recommend a vendor because we don't know where you are.

In the US check these: **broken link removed**

Ken

 

[Dragon Tamer]

1- V+ can be the same 12V battery voltage that I am using for the motor?

Yes, most 555 timers can handel up to 15V easily and continue to work normaly.

2- the transistor? just below the Motor, IRL 3103, is that a TO220AB?

Yes, that is a TO-220 transistor. I can't remember the voltage limit off the top of my head (I think it's 32V) but it can handel 64A of current so it should have no trouble with your motor.

3- Obviously I will need to mount the 3103 on a heat sink?

Yes you should probably have a heat sink for the transistor but since it is only running for about 7 minutes at a time it doesn't need to be too large unless you modify the duty cycle. I would recomend making your heat sink as large as possible to avoid destruction of your transistor.

I also just realised that I did not label the pins for the transistor in that schematic.
The pinout is as follows:
1) Gate, this is connected to the 10k resistor
2) Drain, this is connected to your motor
3) Source, this is connected to ground
4) Drain, this is the heat sink tab on the back of the transistor and is connected to pin 2

 

[Boncuk]

Here is a "super duper" timer circuit for you.

I designed it not to torture the fish before they land in the frying pan.

It consists of two timer circuits each triggering the other.

Starting the circuit the relay pulls in and switches on the load (shown with a green LED). Instead of using a relay for the air pump you might use a MosFet transistor like a BUZ11. At a current of 3A it doesn't need a heatsink. Bolting it to the metal case of the circuit you'll have a heatsink already.

When the activating timer has timed out it triggers the pause timer, which in turn triggers the activating timer when timing out.

Both timers are count down timers and can be preset to any value from 0 to 9 using decimal BCD coder switches.

When your fish start floating with their bellies upside you just hit the reset button which instantaneously activates the air pump and starts the timing sequence.

Too complicated for the purpose? I know people and therefor I love animals.

Regards

Boncuk

 

[GT1000000]

Thanks a bunch, Vince, Ken and Boncuk. You have given me plenty to work with. I am sure I will find one of the circuits will do the trick.
I like the first one, because for a NOOB like me, it should be inexpensive and easy to construct.
I like the second option, because if the first couple of attempts at building my own fail, I could just buy one of the many available kits.
And, third, I like the complexity and elegance of the last one, but I wouldn't have a clue where to begin., quite a bit out of my league and over my head...
gus

 

[Boncuk]

Hi Gus,

if you want to stick to my design I will complete the circuit with clock pulses every minute and design a printed circuit board for you - free of any charge.

I'm here to help and I'm happy if somebody wants my help.

Although the schematic looks complicated it will be fun for you to populate the board(s).

I suggest to use a remote panel for individual timer settings plugged into the clock board which then will take over any new value at timer change overs or by a reset button (also contained on the remote board).

I suppose the device just has to be spill prove which doesn't require to seal it completely.

Regards

Boncuk

 

[GT1000000]

Hi Boncuk,
I could probably pull it off, but since I am quite low on the experience and knowledge ladder, I would almost need some step by step guidance. First of all, I have a couple of questions regarding the size of the completed circuits, as there is a size constraint of about 2" square, and secondly, what is the approximate cost of all of the components? I know most of the basics of electronics, and how to etch a single sided PC board, along with excellent soldering skill. I just don't know what the component schematics stand for, so I would need a thorough and complete parts list.
If you don't think this would be too much trouble for you, I would be inclined to try your design.
By the way, what will the timer look like when it is done...would it have a rotary switch for time length, a momentary push to reset button, is this going to be like two controllers, 1- for on time,2-for off time????
Thanks again,gus

 

[dougy83]

if you want to stick to my design I will complete the circuit with clock pulses every minute and design a printed circuit board for you - free of any charge.

I'm here to help and I'm happy if somebody wants my help.

@Boncuk: You interested in getting [potentially] paid to do this simple board layout? https://www.electro-tech-online.com...schematic-to-eagle-gerber.121698/#post1003473

EDIT: sorry for the off-topic posting...

 

[Boncuk]

@Boncuk: You interested in getting [potentially] paid to do this simple board layout? https://www.electro-tech-online.com...schematic-to-eagle-gerber.121698/#post1003473

EDIT: sorry for the off-topic posting...

Hi dougy83,

the OP already sent me a PM requesting the circuit - and it's also finished and posted in the thread.

Money doesn't have a bad odor and I can use some to get my house finished. Moving into the half finished house today.

Cheers

Boncuk

 

[Boncuk]

Hi Gus,

I guess I can squeeze all parts on a 2X2" board. If you meant 2 square inches total size I'll pull off.

It's impossible to put eight ICs on a board of 1.4" length and width.

I estimate the entire cost for the parts not to exceed US$ 10.

Boncuk

 

[GT1000000]

Hi Gus,

I guess I can squeeze all parts on a 2X2" board. If you meant 2 square inches total size I'll pull off.

It's impossible to put eight ICs on a board of 1.4" length and width.

I estimate the entire cost for the parts not to exceed US$ 10.

Boncuk

The price is perfect. Even if it costs double that.
The size, I can probably squeeze a 2.5"X3" board behind the panel, or even a double-stacked configuration, as depth is not as critical.
Or maybe orient the boards perpendicular to the panel as opposed to parallel. As long as the controls can bemounted on the faceplate.
Thanks, again.
gus

 

[Boncuk]

Hi Gus,

OK then. I'll plan for a "sandwich" not exceeding the dimensions you posted.

Please let me know where you want the power connector and the air pump connector.

Regards

Boncuk

 

[GT1000000]

Hi Boncuk,

Power connections can be just 4 tinned wires, as all of the connections will be soldered directly to their respective sources.

I will also be incorporating a SPDT switch on the panel. One position will be to power the aerator directly, for filling of the live wells, and the other position will be to run the aerator through the timer circuit.

On the surface of the control panel, for the timer circuit, if possible I would like an OFF time pot. and an ON time pot., along with a reset button.

Also, come to think of it, I could have the circuit mounted somewhat remotely and just have leads to the control panel for the pots. and resets etc. What do you think. That could eliminate the size constraint.

Thanks,gus

 

[Boncuk]

Hi Gus,

I buried the idea doing this job using discrete parts.

There would be a total of 10 ICs + 2 BCD coder switches (rotary type), which makes a design even with stacked boards impossible due to size limitations.

Therefor I changed my mind to make one board with a 16X2char LC display and a few push buttons like "menu", "up", "down" and "enter". The LCD backlight will be controlled by daylight, being dimmed at night.

This option provides time intervals up to 1,000 hours (if you like ).

I'll provide a circuit and PCB layout suggestion soon.

Regards

Boncuk

 

[GT1000000]

Hi Boncuk,
Sounds incredibly amazing. I hope I am up to the task of putting something like this together.
Thanks,gus

 

[Boncuk]

Hi Gus,

your PCB size limitation gives me headaches.

This time it's the display unit being larger than 3" long. The board I have designed is now 2.5X3.225".

Some parts have to be mounted on the solder side and since the PCB must be double sided that fact won't matter.

Here is a PCB overlook.

Boncuk

 

[GT1000000]

Hi Boncuk,
The circuit looks like a work of art, do you really think I can put this together?
Also, remember that I have to get all of the parts for this circuit from internet sources and price and availability are BIG concerns.
How big is the display?, I might be able to make an adjustment to my panel configuration.
Thanks again and Best regards, Gus

 

[Boncuk]

Hi Gus,

I think getting the parts from Mouser or Digikey should not be a problem. All parts are standard elements except for the microcontroller (ATMega8P) which will be programmed and shipped to you from Germany.

If so you might skip the 6pin R/A box header (ribbon cable connector) which is required for in-circuit-programming.

The 16X2 char. LC-display measures 80X36mm (3.15X1.147"). The board dimensions are 3.225X2.500".

The PCB layout might look confusing for a beginner. If you follow the assembly instructions I'll provide nothing should go wrong.

However some care has to be taken concerning proper soldering.

Regards

Boncuk