10 Second Operation Bubble Machine

Building on the Instructable to add a 3.5mm switch port to a commonly available bubble machine and the 10 second disco light box - I have combined the two.

The bubble machine is controlled through the use of a 3.5mm switch. This enables children with complex needs a way to have an impact on their surroundings in a positive way. Through previous discussion with the teachers - 10 seconds was discussed as a reasonable length of time for the bubble machine to activate and provide bubbles - although this can be altered.

This modification doesn't allow the bubble machine to be used without a switch as the original switch on the top is used to provide power to a time delay relay. It does require basic soldering skills.

As with previous projects I’ve tried to keep the tools required to a low number and the parts costs as low as practicable. I have assumed that anyone checking my projects out may want to get more actively involved so I'll include basic options for tools and supplies plus a more advanced option. See how you feel.

Parts

Children's bubble machine like this here or here

3.5mm mono jack socket available here

HW-516 time delay relay - https://www.aliexpress.com/item/1005007549722717.html?spm=a2g0o.order_list.order_list_main.45.27991802mqJls1

Signal wire - Cut to lengths as you see fit (I used lengths between 15cm and 20cm here purely to let me keep the wires clear of the internal fan when it spins) I've used a few different colours here but feel free to use whatever colour you prefer - here

Tools

Tools to build this:

Good soldering iron starter kit - available here

or a more advanced soldering station with holder that I'm using here

Lead free solder (smaller packs are available) here

Drill - here

6mm drill bit - here

Wire strippers (I use these as they take the work out of wire sizing) - here

Wire cutters - here

#1 Philips head bladed screw driver - here or hardware shop of choice

AA batteries - this is a 20 pack which has balanced price and performance

These links are only suggestions for these supplies mind. I have included a few affiliate links for some supplies but only because they are cheap and effective supplies.

To open the bubble machine, remove the battery cover and place to one side. Look for the 6 Philips head screws and unscrew them all. Once you have opened the bubble machine case you can see the internals.

Gently pull the fan & motor surround to release it from the case taking care not to put too much pressure on the wires.

Using the screwdriver, unscrew the screws to release the motor surround from the front piece, and then unscrew the screws connecting the sides of the motor surround. Note the cut out at the bottom where the wires pass through. - we will be using this again later.

We will be turning the external switch into a power switch between the red (positive) battery point and the time delay connection to control power to the time delay rely and allow the system to be turned on and off without draining the batteries.

Next we will be making a 3.5mm socket jack that will become the activation switch for the bubbles.

Note: the motor has an orientation with mounts and support padding.

Locate and mark a suitable position for the 3.5mm jack socket. The position needs to be clear of the fan mechanism so take your time to get this correct.

Using the drill and the 6mm drill bit, make the hole for the jack. I propped the casing on a piece of wood to give the drill something to press into. I added a chamfer to the inside of the hole with a countersink bit but a deburr tool or a gentle scrape to remove any burrs.

I then soldered a decent length of signal wire (I used around 20cm) to the normally open contacts of the 3.5mm jack socket. Normally open means that pressing the switch closes the connection to make it - that's what we want.

You can confirm this with the continuity setting on a multi-meter, or if you've bought the mono jacks from the link above - it's these tabs shown.

I added the wired up 3.5mm jack socket to allow me to check the fit of the assembly and make sure it was clear of the where the fan housing would be. It looked good so I fitted the external nut and tightened it to hold the socket in place.

At this point I removed the wire going from the switch to the motor and connected this to the positive power IN on the time delay relay as shown.

I added soldered a length of wire to the positive motor connection and ran this to the positive power OUT of the time delay relay.

I removed the negative wire going from the motor to the battery compartment and connected this to the negative power OUT on the time delay relay as shown.

To provide power for the signal trigger - I ran a loop of wire from the positive power IN on the time delay relay to one side of the trigger.

I connected one wire of the 3.5mm jack to the other side of the signal trigger and the loose wire to the negative power IN on the time delay relay - this provides our switching mechanism. A second wire goes between the negative terminal of the battery compartment and the negative power IN on the time delay relay to complete the circuit.

It's starting to look messy here but stick with me, you're doing great.

At this point - it's time to power up the relay and program it so add batteries to the battery compartment and switch the system on. You should see the LED display on the time delay relay light up and flash 3 times.

If this doesn't make any sense - here's a youtube video which explains it well and a website that gives a good overview.

The board I got has reverse polarity protection which I felt was pretty cool for something so cheap and when you power the module down, it stores the settings.

There's lots of options but we will only deal with the OP (on time) parameter for this project.

Parameters

Parameter description: "OP" - On Power time, "CL" - off time, "LOP" - the number of cycles (1-999 times, "---" represents infinite loop - we won't be using these second two).

Timing range

0.1 seconds (min) to 999 minutes (max)

How to choose the time range?

After setting the mode selection screen parameter value by a short press of the "STOP" button, you can select the time range;

XXX. decimal point in the unit place, time range: 1 second to 999 seconds.

XX.X decimal point in decade place, Timing range: 0.1 seconds to 99.9 seconds

The parameters are independent of each other, but are shared by different Modes.

For example, in P1.1 mode, if you set the on-time "OP" to 5 seconds, then switch to P1.2 mode, it's "OP" will be 5 seconds too.

From the main interface (display 000), short press "SET" button will display "OP" ( "CL", "LOP") and the corresponding time XXX;

Some parameters only use "OP" (such as the mode P1.1, P1.2, P1.3), short press the "SET" key to display only the “OP” and the corresponding time;

Some models have parameters "OP", "CL", "LOP" (such as the mode P3.1, P3.2), short press "SET" button will display "OP" and the corresponding time, “CL” and the corresponding time, “LOP” and the corresponding number of times;

In the main interface by short press "SET" key to see information about the parameters of the current mode - which is handy.

So How do we set parameters?

Technically - you should read the instructions to determine the required operating mode - but we're here to play.

When the module is powered up, the display will show the current work mode (P1.1 default mode so lets use this). To enter the main interface; press "SET" button for 2 seconds and release to enter the mode selection interface; pick a mode by pressing the "UP", "DOWN" key to select the mode (P1.1 ~ P-4). I used P1.1 to keep things easy.

Select the mode (such as P1.1), short press the "SET" button, then the parameter to be set flashes ( "OP" on-time, "CL" off time, "LOP" cycles), by using the "UP", "DOWN" keys to adjust the parameter value. If you press and hold the "UP", "DOWN" keys you get a rapid increase or decrease, a short press of the "UP", "DOWN" keys allows more preciuse increase or decrease by one unit. Once you're happy, short press the "STOP" key to select the decimal point position, select the time range (0.1 seconds to 999 minutes) then short press the "SET" button to set the next parameters of the mode if you want to.

We want to set "OP" to 10.0 seconds, then move the decimal point to the second from right place so the digital display shows 10.0.

After the parameters are set, long press "SET" button for 2 seconds then release. The name of the current mode will flash once, and then return to the main screen. Great work!

Now lets check it to ensure it works (see the video - I've reused the video from my 10 second disco light here, apologies I'll record a fresh section for this shortly) and yes - you'll need a 3.5mm jack button or to bridge out the 3.5mm jack contacts.

Great - lets get everything back into the bubble machine.

PS - On the main interface: If the relay does not work, the display will show "000", with a decimal point under relay state.

There are loads more modes and features available so feel free to have a play with them and have fun.

Remove the batteries from the compartment to make reassembly easier.

Carefully place the motor surround around the motor, making sure no wires are trapped by the surround and screw together then onto the red piece.

Align and slot the fan and motor assembly into the case, check to ensure the tabs either side of the fan motor are positioned correctly. The completed assembly should look as shown in images 3 and 4 (you can see the motor tab under the red wires).

When you're happy with how everything fits into the case and are content that the wires will stay clear of the fan - add the side and screw back into position taking care to align the front section and not trap any wires.

Add 4x AA batteries and test by pressing the normal switch on, then use a 3.5mm jack button (see my other Instructables for how to build one of these if you don't have one to hand, it's here) - if it works, celebrate with a victory lap and a nice cup of tea.

If it doesn't work - check the wire and solder connections at the battery, switch and motor tabs, check that the time delay relay is getting power and for any cables that may have become trapped during reassembly.

One improvement I will make with the next design will be to add a dab of hot glue to keep the wires away from the fan blades on when putting everything back together.