How to Hack a Greeting Card Sound Module to play entire sound clip

I bought a bunch of the recordable greeting card sound modules for a project.  The problem is that these sound modules only play when the greeting card (circuit) is open so only a portion of the sound clip is played if you close the card (circuit).  Is there an easy way to hack these sound modules so that the entire sound clip is played each time they are activated?

sort by: active | newest | oldest
iceng3 years ago

Yes and smd components will fit the card.

DeKooy (author)  iceng3 years ago

Is it as simple as adding a capacitor so that there is enough "juice" to power the 10 second sound clip? Can you provide any details on the modification? If you haven't already guessed I am a newbie...

iceng DeKooy3 years ago

That word newbie scares me ;-)

A capacitor that supplies enough current to power a sound module will be huge.

I suggest ( no smd for a newbie ) an SCR, a disc capacitor, a 100 or 47 ohm resistor 1/8 or 1/4 Watt, and regrettably a second coin battery.

The extra battery is for the voltage drop for the SCR and the card switch turns on the SCR which stays on by passing the old S1 switch until the music module turns off or lowers the current.



One way to do this is to add an electronic latch, also called monostable, also called flip-flop, to your circuit.


These things are well understood to those versed in the art, and somebody here could help you out, if you want to go that route; i.e. to build a latching circuit, compatible with the existing battery, and input of your greeting card module. No guarantees about getting the finished circuit to fit back in the card.

Another way to do this is to build a mechanical latch. That is to say you replace the existing momentary switch, with a kind of switch that just permanently stays closed. For example if you have two springy contacts, held apart by a thin strip of plastic, and the plastic strip can be pulled loose by opening the card, then you've got a mechanical switch that closes and stays closed.

The problem with this mechanical latch I've just described, is that now the switch is just stuck closed, and depending on how the module is wired that might cause the module to just loop its sound sample over, and over, and over again...

So if you only want the sample to play completely, exactly once, and without involvement from the victim, I mean whoever opens the card, then the electronic latch is probably what you need.

It is too bad this greeting card was not designed to work exactly the way you want it to work, because at that stage in the process it would have been really easy to change.

You mean other than keeping the card open for the entire time?

Easy way? No. But it can be done. You'll just need additional circuitry to make it work. When you open the card you make a connection between the battery and the circuit. When you close it the circuit is powered off. So you need a circuit that will sit between the battery and the card's circuit and keep the card powered for a determined amount of time. You may have a hard time keeping it within the card though.